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  • VTD-XML Parsing Performance (speed critical factor). Requesting Feedback/Comments

    - by andreas
    Hello, I am about to use VTD-XML (found at http://vtd-xml.sourceforge.net/) but I am interested in getting real-case usage feedback, by any one that has used the library and has any comments. At the URL (http://vtd-xml.sourceforge.net/) there are benchmarks but if someone has used VTD-XML and has comments FOR it I would like to hear them. Speed is a critical factor in the application and comments after real-case usage, by developers, is what i am looking for. Regards,

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  • Fermat factorization method limit

    - by Fakrudeen
    I am trying to implement Fermat's factorization [Algorithm C in Art of computer programming Vol. 2]. Unfortunately in my edition [ISBN 81-7758-335-2], this algorithm is printed incorrectly. what should be the condition on factor-inner loop below? I am running the loop till y <= n [passed in as limit]. (if (< limit y) 0 (factor-inner x (+ y 2) (- r y) limit)) Is there anyway to avoid this condition altogether, as it will double the speed of loop? (define (factor n) (let ( ( square-root (inexact->exact (floor (sqrt n))) ) ) (factor-inner (+ (* 2 square-root) 1) 1 (- (* square-root square-root) n) n) ) ) (define (factor-inner x y r limit) (if (= r 0) (/ (- x y) 2) (begin (display x)(display " ")(display y)(display " ")(display r)(newline) ;(sleep-current-thread 1) (if (< r 0) (factor-inner (+ x 2) y (+ r x) limit) (if (< limit y) 0 (factor-inner x (+ y 2) (- r y) limit)) ) ) ) )

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  • I'm trying to implement 2 factor authentication on the cheap. How would I do that?

    - by Biff MaGriff
    Ok so I need 2 of the 3. Something the user knows. Something the user has. Something the user is. I have a system that is exposed to the internet and we need clients to connect in a secure manner to satisfy our security standards. I'm thinking when a user registers to use our system we send them an application that they install on their home system. The application generates a key based on a timed randomness algorithm. Our application server has the same algorithm so when the user submits their credentials with the key we know that they are a legitimate user. Is this a valid method of 2 factor authentication? What is another way of doing this? Are there any pitfalls that I should be aware of? Thanks for your help!

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  • How to create a column containing a string of stars to inidcate levels of a factor in a data frame i

    - by PaulHurleyuk
    (second question today - must be a bad day) I have a dataframe with various columns, inculding a concentration column (numeric), a flag highlighting invalid results (boolean) and a description of the problem (character) dput(df) structure(list(x = c(1, 2, 3, 4, 5, 6, 7, 8, 9, 10), rawconc = c(77.4, 52.6, 86.5, 44.5, 167, 16.2, 59.3, 123, 1.95, 181), reason = structure(c(NA, NA, 2L, NA, NA, NA, 2L, 1L, NA, NA), .Label = c("Fails Acceptance Criteria", "Poor Injection"), class = "factor"), flag = c("False", "False", "True", "False", "False", "False", "True", "True", "False", "False" )), .Names = c("x", "rawconc", "reason", "flag"), row.names = c(NA, -10L), class = "data.frame") I can create a column with the numeric level of the reason column df$level<-as.numeric(df$reason) df x rawconc reason flag level 1 1 77.40 <NA> False NA 2 2 52.60 <NA> False NA 3 3 86.50 Poor Injection True 2 4 4 44.50 <NA> False NA 5 5 167.00 <NA> False NA 6 6 16.20 <NA> False NA 7 7 59.30 Poor Injection True 2 8 8 123.00 Fails Acceptance Criteria True 1 9 9 1.95 <NA> False NA 10 10 181.00 <NA> False NA and here's what I want to do to create a column with 'level' many stars, but it fails df$stars<-paste(rep("*",df$level)sep="",collapse="") Error: unexpected symbol in "df$stars<-paste(rep("*",df$level)sep" df$stars<-paste(rep("*",df$level),sep="",collapse="") Error in rep("*", df$level) : invalid 'times' argument rep("*",df$level) Error in rep("*", df$level) : invalid 'times' argument df$stars<-paste(rep("*",pmax(df$level,0,na.rm=TRUE)),sep="",collapse="") Error in rep("*", pmax(df$level, 0, na.rm = TRUE)) : invalid 'times' argument It seems that rep needs to be fed one value at a time. I feel that this should be possible (and my gut says 'use lapply' but my apply fu is v. poor) ANy one want to try ?

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  • Problem with JavaScript arithmetic

    - by Lynn
    I have a form for my customers to add budget projections. A prominent user wants to be able to show dollar values in either dollars, Kila-dollars or Mega-dollars. I'm trying to achieve this with a group of radio buttons that call the following JavaScript function, but am having problems with rounding that make the results look pretty crummy. Any advice would be much appreciated! Lynn function setDollars(new_mode) { var factor; var myfield; var myval; var cur_mode = document.proj_form.cur_dollars.value; if(cur_mode == new_mode) { return; } else if((cur_mode == 'd')&&(new_mode == 'kd')) { factor = "0.001"; } else if((cur_mode == 'd')&&(new_mode == 'md')) { factor = "0.000001"; } else if((cur_mode == 'kd')&&(new_mode == 'd')) { factor = "1000"; } else if((cur_mode == 'kd')&&(new_mode == 'md')) { factor = "0.001"; } else if((cur_mode == 'md')&&(new_mode == 'kd')) { factor = "1000"; } else if((cur_mode == 'md')&&(new_mode == 'd')) { factor = "1000000"; } document.proj_form.cur_dollars.value = new_mode; var cur_idx = document.proj_form.cur_idx.value; var available_slots = 13 - cur_idx; var td_name; var cell; var new_value; //Adjust dollar values for projections for(i=1;i<13;i++) { var myfield = eval('document.proj_form.proj_'+i); if(myfield.value == '') { myfield.value = 0; } var myval = parseFloat(myfield.value) * parseFloat(factor); myfield.value = myval; if(i < cur_idx) { document.getElementById("actual_"+i).innerHTML = myval; } }

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  • Unique prime factors using HashSet

    - by theGreenCabbage
    I wrote a method that recursively finds prime factors. Originally, the method simply printed values. I am currently trying to add them to a HashSet to find the unique prime factors. In each of my original print statements, I added a primes.add() in order to add that particular integer into my set. My printed output remains the same, for example, if I put in the integer 24, I get 2*2*2*3. However, as soon as I print the HashSet, the output is simply [2]. public static Set<Integer> primeFactors(int n) { Set<Integer> primes = new HashSet<Integer>(); if(n <= 1) { System.out.print(n); primes.add(n); } else { for(int factor = 2; factor <= n; factor++) { if(n % factor == 0) { System.out.print(factor); primes.add(factor); if(factor < n) { System.out.print('*'); primeFactors(n/factor); } return primes; } } } return primes; } I have tried debugging via putting print statements around every line, but was unable to figure out why my .add() was not adding some values into my HashSet.

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  • dmidecode showing more ram slots than available?

    - by Jestep
    I have some failing RAM in a server and I ran dmidecode to figure out what tyoe of RAM I needed to replace it with. The server has 6 RAM slots, 4 of which are in use. When I run dmidecode this is what I get. dmidecode 2.10 SMBIOS 2.4 present. Handle 0x001F, DMI type 17, 27 bytes Memory Device Array Handle: 0x001E Error Information Handle: No Error Total Width: 72 bits Data Width: 64 bits Size: 2048 MB Form Factor: DIMM Set: 1 Locator: JXXX Bank Locator: DIMM 00 Type: DDR2 Type Detail: Synchronous Speed: 667 MHz Manufacturer: Not Specified Serial Number: Not Specified Asset Tag: Not Specified Part Number: Not Specified Handle 0x0020, DMI type 17, 27 bytes Memory Device Array Handle: 0x001E Error Information Handle: No Error Total Width: 72 bits Data Width: 64 bits Size: 2048 MB Form Factor: DIMM Set: 1 Locator: JXXX Bank Locator: DIMM 01 Type: DDR2 Type Detail: Synchronous Speed: 667 MHz Manufacturer: Not Specified Serial Number: Not Specified Asset Tag: Not Specified Part Number: Not Specified Handle 0x0021, DMI type 17, 27 bytes Memory Device Array Handle: 0x001E Error Information Handle: No Error Total Width: Unknown Data Width: Unknown Size: No Module Installed Form Factor: DIMM Set: 1 Locator: JXXX Bank Locator: DIMM 02 Type: DDR2 Type Detail: Synchronous Speed: 667 MHz Manufacturer: Not Specified Serial Number: Not Specified Asset Tag: Not Specified Part Number: Not Specified Handle 0x0022, DMI type 17, 27 bytes Memory Device Array Handle: 0x001E Error Information Handle: No Error Total Width: Unknown Data Width: Unknown Size: No Module Installed Form Factor: DIMM Set: 1 Locator: JXXX Bank Locator: DIMM 03 Type: DDR2 Type Detail: Synchronous Speed: 667 MHz Manufacturer: Not Specified Serial Number: Not Specified Asset Tag: Not Specified Part Number: Not Specified Handle 0x0023, DMI type 17, 27 bytes Memory Device Array Handle: 0x001E Error Information Handle: No Error Total Width: 72 bits Data Width: 64 bits Size: 2048 MB Form Factor: DIMM Set: 1 Locator: JXXX Bank Locator: DIMM 10 Type: DDR2 Type Detail: Synchronous Speed: 667 MHz Manufacturer: Not Specified Serial Number: Not Specified Asset Tag: Not Specified Part Number: Not Specified Handle 0x0024, DMI type 17, 27 bytes Memory Device Array Handle: 0x001E Error Information Handle: No Error Total Width: 72 bits Data Width: 64 bits Size: 2048 MB Form Factor: DIMM Set: 1 Locator: JXXX Bank Locator: DIMM 11 Type: DDR2 Type Detail: Synchronous Speed: 667 MHz Manufacturer: Not Specified Serial Number: Not Specified Asset Tag: Not Specified Part Number: Not Specified Handle 0x0025, DMI type 17, 27 bytes Memory Device Array Handle: 0x001E Error Information Handle: No Error Total Width: Unknown Data Width: Unknown Size: No Module Installed Form Factor: DIMM Set: 1 Locator: JXXX Bank Locator: DIMM 12 Type: DDR2 Type Detail: Synchronous Speed: 667 MHz Manufacturer: Not Specified Serial Number: Not Specified Asset Tag: Not Specified Part Number: Not Specified Handle 0x0026, DMI type 17, 27 bytes Memory Device Array Handle: 0x001E Error Information Handle: No Error Total Width: Unknown Data Width: Unknown Size: No Module Installed Form Factor: DIMM Set: 1 Locator: JXXX Bank Locator: DIMM 13 Type: DDR2 Type Detail: Synchronous Speed: 667 MHz Manufacturer: Not Specified Serial Number: Not Specified Asset Tag: Not Specified Part Number: Not Specified Does anyone know why it would show 8 slots, with 4 empty instead of 6 slots with 2 empty? Also, but my records and by other tools, the server has 16Gb and not 8Gb in it currently. grep MemTotal /proc/meminfo MemTotal: 16435808 kB The board is a Tyan S5372-LC, running CentOS 5.4 x64. Also, my error log is showing errors in bank 6. Is there any way to determine which slot bank 6 is in via: dmidecode?

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  • Parse youtube links PHP

    - by Isis
    Hello 34|http://v19.lscache8.c.youtube.com/videoplayback?ip=0.0.0.0&sparams=id,expire,ip,ipbits,itag,algorithm,burst,factor,oc:U0dWRlZUVF9FSkNNNl9OTlhF&fexp=902210&algorithm=throttle-factor&itag=34&ipbits=0&burst=40&sver=3&expire=1271696400&key=yt1&signature=583C4A85FA65B6B9782B8B4B5E1F1C08D9EADCA3.5B28033470580BC52EB92A1CB71DBAFE0C4A2A8D&factor=1.25&id=cf3cec58d98073dc,5|http://v24.lscache4.c.youtube.com/videoplayback?ip=0.0.0.0&sparams=id,expire,ip,ipbits,itag,algorithm,burst,factor,oc:U0dWRlZUVF9FSkNNNl9OTlhF&fexp=902210&algorithm=throttle-factor&itag=5&ipbits=0&burst=40&sver=3&expire=1271696400&key=yt1&signature=7B74075BAA26B05A028B2219FD52D7A45197F555.A8878413DC7BB3FFAB0C9219CBD3FCDD7221B440&factor=1.25&id=cf3cec58d98073dc How to parse this text for: 34 http://... (before ,5|) 5 http://... to end Previously it was done so: if (preg_match_all('#|(.*?),#', $urlmap, $b)) { } Sorry for baaaaad english

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  • Lazy sequence or recur for mathematical power function?

    - by StackedCrooked
    As an exercise I implemented the mathematical power function. Once using recur: (defn power [a n] (let [multiply (fn [x factor i] (if (zero? i) x (recur (* x factor) factor (dec i))))] (multiply a a (dec n)))) And once with lazy-seq: (defn power [a n] (letfn [(multiply [a factor] (lazy-seq (cons a (multiply (* a factor) factor))))] (nth (multiply a a) (dec n)))) Which implementation do you think is superior? I truly have no idea.. (I'd use recur because it's easier to understand.) I read that lazy-seq is fast because is uses internal caching. But I don't see any opportunities for caching in my sample. Am I overlooking something?

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  • Warning as Error - How to rid these

    - by coffeeaddict
    I cannot figure out how to get rid of errors that basically should not be halting my compile in VS 2010 and should not be show stoppers, or at least I will fix them later but I don't want the compile to just error and halt on these kinds of problems. For example I'm getting the following error: Error 1 Warning as Error: XML comment on 'ScrewTurn.Wiki.SearchEngine.Relevance.Finalize(float)' has a paramref tag for 'IsFinalized', but there is no parameter by that name C:\www\Wiki\Screwturn3_0_2_509\SearchEngine\Relevance.cs 60 70 SearchEngine for this code: /// /// Normalizes the relevance after finalization. /// /// The normalization factor. /// If is false ( was not called). public void NormalizeAfterFinalization(float factor) { if(factor < 0) throw new ArgumentOutOfRangeException("factor", "Factor must be greater than or equal to zero"); if(!isFinalized) throw new InvalidOperationException("Normalization can be performed only after finalization"); value = value * factor; } I looked in Tools | Options and I don't see where I can tweak the compiler and tell it not to worry about comment or XHTML based errors.

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  • break dataframe into subsets by factor values, send to function that returns glm class, how to recom

    - by Alex Holcombe
    Thanks to Hadley's plyr package ddply function we can take a dataframe, break it down into subdataframes by factors, send each to a function, and then combine the function results for each subdataframe into a new dataframe. But what if the function returns an object of a class like glm or in my case, a c("glm", "lm"). Then, these can't be combined into a dataframe can they? I get this error instead Error in as.data.frame.default(x[[i]], optional = TRUE, stringsAsFactors = stringsAsFactors) : cannot coerce class 'c("glm", "lm")' into a data.frame Is there some more flexible data structure that will accommodate all the complex glm class results of my function calls, preserving the information regarding the dataframe subsets? Or should this be done in an entirely different way?

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  • A Digg-like rotating homepage of popular content, how to include date as a factor?

    - by Ferdy
    I am building an advanced image sharing web application. As you may expect, users can upload images and others can comments on it, vote on it, and favorite it. These events will determine the popularity of the image, which I capture in a "karma" field. Now I want to create a Digg-like homepage system, showing the most popular images. It's easy, since I already have the weighted Karma score. I just sort on that descendingly to show the 20 most valued images. The part that is missing is time. I do not want extremely popular images to always be on the homepage. I guess an easy solution is to restrict the result set to the last 24 hours. However, I'm also thinking that in order to keep the image rotation occur throughout the day, time can be some kind of variable where its offset has an influence on the image's sorting. Specific questions: Would you recommend the easy scenario (just sort for best images within 24 hours) or the more sophisticated one (use datetime offset as part of the sorting)? If you advise the latter, any help on the mathematical solution to this? Would it be best to run a scheduled service to mark images for the homepage, or would you advise a direct query (I'm using MySQL) As an extra note, the homepage should support paging and on a quiet day should include entries of days before in order to make sure it is always "filled" I'm not asking the community to build this algorithm, just looking for some advise :)

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  • How can I factor out repeated expressions in an SQL Query? Column aliases don't seem to be the ticke

    - by Weston C
    So, I've got a query that looks something like this: SELECT id, DATE_FORMAT(CONVERT_TZ(callTime,'+0:00','-7:00'),'%b %d %Y') as callDate, DATE_FORMAT(CONVERT_TZ(callTime,'+0:00','-7:00'),'%H:%i') as callTimeOfDay, SEC_TO_TIME(callLength) as callLength FROM cs_calldata WHERE customerCode='999999-abc-blahblahblah' AND CONVERT_TZ(callTime,'+0:00','-7:00') >= '2010-04-25' AND CONVERT_TZ(callTime,'+0:00','-7:00') <= '2010-05-25' If you're like me, you probably start thinking that maybe it would improve readability and possibly the performance of this query if I wasn't asking it to compute CONVERT_TZ(callTime,'+0:00','-7:00') four separate times. So I try to create a column alias for that expression and replace further occurances with that alias: SELECT id, CONVERT_TZ(callTime,'+0:00','-7:00') as callTimeZoned, DATE_FORMAT(callTimeZoned,'%b %d %Y') as callDate, DATE_FORMAT(callTimeZoned,'%H:%i') as callTimeOfDay, SEC_TO_TIME(callLength) as callLength FROM cs_calldata WHERE customerCode='5999999-abc-blahblahblah' AND callTimeZoned >= '2010-04-25' AND callTimeZoned <= '2010-05-25' This is when I learned, to quote the MySQL manual: Standard SQL disallows references to column aliases in a WHERE clause. This restriction is imposed because when the WHERE clause is evaluated, the column value may not yet have been determined. So, that approach would seem to be dead in the water. How is someone writing queries with recurring expressions like this supposed to deal with it?

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  • How do I construct a 3D model of a room from 2 stereo cameras? What is the determining factor to an

    - by yasumi
    Currently, I have extracted depth points to construct a 3D model from 2 stereo cameras. The methods I have used are openCV graphCut method and a software from http://sourceforge.net/projects/reconststereo/. However, the generated 3D models are not very accurate, which leads me to question: 1) What is the problem with pixel-based method? 2) Should I change my pixel-based method to feature-based or object-recognition-based method? Is there a best method? 3) Are there any other ways to do such reconstruction? Additionally, the depth extracted comes only from 2 images. What if I am turning the camera 360 degrees to obtain a video? Looking forward to suggestion on how to combine this depth information. Thank you very much :)

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  • how to re-factor a web site for 3G?

    - by George2
    Hello everyone, I have a traditional web site which serves users from desktop computer browsers. I am using Microsoft technologies, like ASP.Net, C#, .Net, SQL Server 2008, IIS and Windows Server 2008. Nowadays, more and more users are using 3G mobile phones, and I am wondering from software perspective, how to add new features to my web site (do I need a client application runs on mobile phone as well?) so that 3G users could have good user experience or new kinds of 3G specific applications? Any recommended documents or real samples are welcome. For 3G users, I want to distinguish from traditional less-powered and slow network access GPRS mobile phone. thanks in advance, George

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  • Is the W3 standard a major factor when google decides SERP position?

    - by Camran
    I have a dynamic php website which index only has around 800 errors according to the w3 validator online. I have tried checking major websites like ebay, stackoverflow and others also, all with around 400 errors. So my first thought is, what good is that validator when it always displays errors? Secondly, will the errors affect my SERP ranking? ie, will me fixing these errors as good as I can increase my Google search position? Thanks

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  • VLC 2.0.3 on Lubuntu 12.04: No audio?

    - by drezabek
    I am on Lubuntu 12.04, and I have installed VLC media player version 2.0.3. When I try and play an audio file, it appears to load fine, and the media position bar displays the progress, and it says it is playing, but I can't here any thing through my speakers. I can hear game audio, web audio, and audio from SMPlayer just fine, but with VLC, I can't here anything. Below is the "Messages" output with the verbosity option set to "2 (debug)" main debug: processing request item: The Bottom, node: Playlist, skip: 0 main debug: resyncing on The Bottom main debug: The Bottom is at 0 main debug: starting playback of the new playlist item main debug: resyncing on The Bottom main debug: The Bottom is at 0 main debug: creating new input thread main debug: Creating an input for 'The Bottom' main debug: TIMER input launching for 'Floex - Machinarium Soundtrack - 01 The Bottom.flac' : 23.706 ms - Total 23.706 ms / 1 intvls (Avg 23.706 ms) main debug: using timeshift granularity of 50 MiB, in path '/tmp' main debug: `file:///home/doug/Music/unsorted/Floex%20-%20Machinarium%20Soundtrack/Floex%20-%20Machinarium%20Soundtrack%20-%2001%20The%20Bottom.flac' gives access `file' demux `' path `/home/doug/Music/unsorted/Floex%20-%20Machinarium%20Soundtrack/Floex%20-%20Machinarium%20Soundtrack%20-%2001%20The%20Bottom.flac' main debug: creating demux: access='file' demux='' location='/home/doug/Music/unsorted/Floex%20-%20Machinarium%20Soundtrack/Floex%20-%20Machinarium%20Soundtrack%20-%2001%20The%20Bottom.flac' file='/home/doug/Music/unsorted/Floex - Machinarium Soundtrack/Floex - Machinarium Soundtrack - 01 The Bottom.flac' main debug: looking for access_demux module: 3 candidates main debug: no access_demux module matching "file" could be loaded main debug: TIMER module_need() : 2.332 ms - Total 2.332 ms / 1 intvls (Avg 2.332 ms) main debug: creating access 'file' location='/home/doug/Music/unsorted/Floex%20-%20Machinarium%20Soundtrack/Floex%20-%20Machinarium%20Soundtrack%20-%2001%20The%20Bottom.flac', path='/home/doug/Music/unsorted/Floex - Machinarium Soundtrack/Floex - Machinarium Soundtrack - 01 The Bottom.flac' main debug: looking for access module: 2 candidates filesystem debug: opening file `/home/doug/Music/unsorted/Floex - Machinarium Soundtrack/Floex - Machinarium Soundtrack - 01 The Bottom.flac' main debug: using access module "filesystem" main debug: TIMER module_need() : 0.762 ms - Total 0.762 ms / 1 intvls (Avg 0.762 ms) main debug: Using stream method for AStream* main debug: starting pre-buffering main debug: received first data after 0 ms main debug: pre-buffering done 1024 bytes in 0s - 43478 KiB/s main debug: looking for stream_filter module: 7 candidates main debug: no stream_filter module matching "any" could be loaded main debug: TIMER module_need() : 0.236 ms - Total 0.236 ms / 1 intvls (Avg 0.236 ms) main debug: looking for stream_filter module: 1 candidate main debug: using stream_filter module "stream_filter_record" main debug: TIMER module_need() : 0.156 ms - Total 0.156 ms / 1 intvls (Avg 0.156 ms) main debug: creating demux: access='file' demux='' location='/home/doug/Music/unsorted/Floex%20-%20Machinarium%20Soundtrack/Floex%20-%20Machinarium%20Soundtrack%20-%2001%20The%20Bottom.flac' file='/home/doug/Music/unsorted/Floex - Machinarium Soundtrack/Floex - Machinarium Soundtrack - 01 The Bottom.flac' main debug: looking for demux module: 54 candidates flacsys debug: Picture type=3 mime=image/png description='' file length=679371 qt4 debug: IM: Setting an input main debug: looking for packetizer module: 21 candidates main debug: using packetizer module "packetizer_flac" main debug: TIMER module_need() : 0.211 ms - Total 0.211 ms / 1 intvls (Avg 0.211 ms) main debug: using demux module "flacsys" main debug: TIMER module_need() : 4.023 ms - Total 4.023 ms / 1 intvls (Avg 4.023 ms) main debug: looking for a subtitle file in /home/doug/Music/unsorted/Floex - Machinarium Soundtrack/ main debug: looking for meta reader module: 2 candidates main debug: using meta reader module "taglib" main debug: TIMER module_need() : 5.245 ms - Total 5.245 ms / 1 intvls (Avg 5.245 ms) main debug: removing module "taglib" main debug: `file:///home/doug/Music/unsorted/Floex%20-%20Machinarium%20Soundtrack/Floex%20-%20Machinarium%20Soundtrack%20-%2001%20The%20Bottom.flac' successfully opened main debug: selecting program id=0 main debug: looking for decoder module: 30 candidates main debug: using decoder module "flac" main debug: TIMER module_need() : 0.442 ms - Total 0.442 ms / 1 intvls (Avg 0.442 ms) main debug: Buffering 0% flac debug: decode STREAMINFO flac debug: channels:2 samplerate:44100 bitspersamples:16 flac debug: STREAMINFO decoded main debug: Buffering 30% main debug: recycling audio output main debug: looking for audio output module: 3 candidates main debug: Buffering 61% pulse debug: using stereo channel map pulse debug: using library version 1.1.0 pulse debug: (compiled with version 1.1.0, protocol 26) main debug: Buffering 92% main debug: Stream buffering done (371 ms in 2 ms) pulse debug: connected locally to unix:/home/doug/.pulse/dce22254e867f905188a2ce200000003-runtime/native as client #14 pulse debug: using protocol 26, server protocol 26 pulse debug: using buffer metrics: maxlength=4194304, tlength=9880, prebuf=0, minreq=3528 pulse debug: connected to sink 0: alsa_output.pci-0000_00_14.2.analog-stereo main debug: using audio output module "pulse" main debug: TIMER module_need() : 4.571 ms - Total 4.571 ms / 1 intvls (Avg 4.571 ms) main debug: output 's16l' 44100 Hz Stereo frame=1 samples/4 bytes main debug: mixer 'f32l' 44100 Hz Stereo frame=1 samples/8 bytes main debug: filter(s) 'f32l'->'s16l' 44100 Hz->44100 Hz Stereo->Stereo main debug: looking for audio filter module: 14 candidates audio_format debug: f32l->s16l, bits per sample: 32->16 main debug: using audio filter module "audio_format" main debug: TIMER module_need() : 0.187 ms - Total 0.187 ms / 1 intvls (Avg 0.187 ms) main debug: conversion pipeline completed main debug: looking for audio mixer module: 2 candidates main debug: using audio mixer module "float32_mixer" main debug: TIMER module_need() : 0.125 ms - Total 0.125 ms / 1 intvls (Avg 0.125 ms) main debug: input 's16l' 44100 Hz Stereo frame=1 samples/4 bytes main debug: looking for audio filter module: 1 candidate scaletempo debug: format: 44100 rate, 2 nch, 4 bps, fl32 scaletempo debug: params: 30 stride, 0.200 overlap, 14 search scaletempo debug: 1.000 scale, 1323.000 stride_in, 1323 stride_out, 1059 standing, 264 overlap, 617 search, 2204 queue, fl32 mode main debug: using audio filter module "scaletempo" main debug: TIMER module_need() : 0.233 ms - Total 0.233 ms / 1 intvls (Avg 0.233 ms) main debug: filter(s) 's16l'->'f32l' 44100 Hz->44100 Hz Stereo->Stereo pulse debug: listing sink alsa_output.pci-0000_00_14.2.analog-stereo (0): Built-in Audio Analog Stereo main debug: looking for audio filter module: 14 candidates audio_format debug: s16l->f32l, bits per sample: 16->32 main debug: using audio filter module "audio_format" main debug: TIMER module_need() : 0.147 ms - Total 0.147 ms / 1 intvls (Avg 0.147 ms) main debug: conversion pipeline completed pulse debug: base volume: 65536 main debug: looking for audio filter module: 1 candidate equalizer debug: equalizer loaded for 44100 Hz with 10 bands 2 pass equalizer debug: 60 Hz -> factor:0.000000 alpha:0.003013 beta:0.993973 gamma:1.993901 equalizer debug: 170 Hz -> factor:0.000000 alpha:0.008490 beta:0.983019 gamma:1.982437 equalizer debug: 310 Hz -> factor:0.000000 alpha:0.015374 beta:0.969252 gamma:1.967331 equalizer debug: 600 Hz -> factor:0.000000 alpha:0.029328 beta:0.941343 gamma:1.934254 equalizer debug: 1000 Hz -> factor:0.000000 alpha:0.047918 beta:0.904163 gamma:1.884869 equalizer debug: 3000 Hz -> factor:0.000000 alpha:0.130408 beta:0.739184 gamma:1.582718 equalizer debug: 6000 Hz -> factor:0.000000 alpha:0.226555 beta:0.546889 gamma:1.015267 equalizer debug: 12000 Hz -> factor:0.000000 alpha:0.344937 beta:0.310127 gamma:-0.181410 equalizer debug: 14000 Hz -> factor:0.000000 alpha:0.366438 beta:0.267123 gamma:-0.521151 equalizer debug: 16000 Hz -> factor:0.000000 alpha:0.379009 beta:0.241981 gamma:-0.808451 main debug: using audio filter module "equalizer" main debug: TIMER module_need() : 0.353 ms - Total 0.353 ms / 1 intvls (Avg 0.353 ms) main debug: filter(s) 'f32l'->'f32l' 44100 Hz->44100 Hz Stereo->Stereo main debug: conversion pipeline completed main debug: looking for visualization2 module: 1 candidate main debug: looking for text renderer module: 2 candidates freetype debug: Building font databases. freetype debug: Took 0 microseconds freetype debug: Using Serif Bold as font from file /usr/share/fonts/truetype/ttf-dejavu/DejaVuSans.ttf freetype debug: using fontsize: 2 main debug: using text renderer module "freetype" main debug: TIMER module_need() : 3.278 ms - Total 3.278 ms / 1 intvls (Avg 3.278 ms) main debug: looking for video filter2 module: 18 candidates swscale debug: 32x32 chroma: YUVA -> 16x16 chroma: RGBA with scaling using Bicubic (good quality) main debug: using video filter2 module "swscale" main debug: TIMER module_need() : 1.037 ms - Total 1.037 ms / 1 intvls (Avg 1.037 ms) main debug: looking for video filter2 module: 18 candidates yuvp debug: YUVP to YUVA converter main debug: using video filter2 module "yuvp" main debug: TIMER module_need() : 0.156 ms - Total 0.156 ms / 1 intvls (Avg 0.156 ms) main debug: Deinterlacing available main debug: deinterlace 0, mode blend, is_needed 0 main debug: Opening vout display wrapper main debug: looking for vout display module: 6 candidates main debug: looking for vout window xid module: 4 candidates qt4 debug: requesting video... qt4 debug: Video was requested 0, 0 main debug: using vout window xid module "qt4" main debug: TIMER module_need() : 61.671 ms - Total 61.671 ms / 1 intvls (Avg 61.671 ms) main debug: looking for inhibit module: 2 candidates main debug: using inhibit module "xdg_screensaver" main debug: TIMER module_need() : 0.336 ms - Total 0.336 ms / 1 intvls (Avg 0.336 ms) xdg_screensaver debug: started xdg-screensaver (PID = 6682) xcb_xv debug: connected to X11.0 server xcb_xv debug: vendor : The X.Org Foundation xcb_xv debug: version: 11103000 xcb_xv debug: using screen 0x15a xcb_xv debug: using XVideo extension v2.2 xcb_xv debug: using adaptor NV17 Video Texture xcb_xv debug: using port 310 xcb_xv debug: using image format 0x30323449 xcb_xv debug: using X11 visual ID 0x21 (depth: 24) xcb_xv debug: using X11 window 0x03400000 xcb_xv debug: using X11 graphic context 0x03400002 main debug: VoutDisplayEvent 'fullscreen' 0 main debug: VoutDisplayEvent 'resize' 800x500 window main debug: using vout display module "xcb_xv" main debug: TIMER module_need() : 69.890 ms - Total 69.890 ms / 1 intvls (Avg 69.890 ms) main debug: original format sz 800x500, of (0,0), vsz 800x500, 4cc I420, sar 1:1, msk r0x0 g0x0 b0x0 main debug: removing module "freetype" main debug: looking for text renderer module: 2 candidates freetype debug: Building font databases. freetype debug: Took 0 microseconds freetype debug: Using Serif Bold as font from file /usr/share/fonts/truetype/ttf-dejavu/DejaVuSans.ttf freetype debug: using fontsize: 2 main debug: using text renderer module "freetype" main debug: TIMER module_need() : 4.552 ms - Total 4.552 ms / 1 intvls (Avg 4.552 ms) main debug: using visualization2 module "visual" main debug: TIMER module_need() : 84.104 ms - Total 84.104 ms / 1 intvls (Avg 84.104 ms) main debug: filter(s) 'f32l'->'f32l' 44100 Hz->44100 Hz Stereo->Stereo main debug: conversion pipeline completed main debug: filter(s) 'f32l'->'f32l' 44100 Hz->44100 Hz Stereo->Stereo main debug: conversion pipeline completed main debug: filter(s) 'f32l'->'f32l' 48510 Hz->44100 Hz Stereo->Stereo main debug: looking for audio filter module: 14 candidates main debug: using audio filter module "samplerate" main debug: TIMER module_need() : 0.375 ms - Total 0.375 ms / 1 intvls (Avg 0.375 ms) main debug: conversion pipeline completed main debug: End of audio preroll main debug: Decoder buffering done in 91 ms main warning: PTS is out of range (-9269), dropping buffer pulse debug: deferring start (190703 us) main debug: looking for video blending module: 1 candidate main debug: using video blending module "blend" main debug: TIMER module_need() : 0.275 ms - Total 0.275 ms / 1 intvls (Avg 0.275 ms) main debug: Detected interlaced video main debug: deinterlace 0, mode blend, is_needed 1 xcb_xv debug: display is visible pulse debug: starting deferred pulse warning: too late by 93760 us pulse debug: changed sample rate to 44186 Hz pulse debug: started pulse warning: too late by 94474 us pulse debug: changed sample rate to 44229 Hz pulse warning: too late by 93532 us pulse debug: changed sample rate to 44272 Hz pulse warning: too late by 92829 us pulse debug: changed sample rate to 44315 Hz pulse warning: too late by 92132 us pulse debug: changed sample rate to 44358 Hz xcb_xv debug: display is visible pulse warning: too late by 91534 us pulse debug: changed sample rate to 44401 Hz xcb_xv debug: display is visible pulse warning: too late by 89482 us pulse debug: changed sample rate to 44440 Hz xcb_xv debug: display is visible xcb_xv debug: display is visible pulse warning: too late by 87529 us pulse debug: changed sample rate to 44479 Hz pulse warning: too late by 84577 us pulse debug: changed sample rate to 44504 Hz main debug: auto hiding mouse cursor pulse warning: too late by 78562 us pulse debug: changed sample rate to 44492 Hz pulse warning: too late by 68015 us pulse debug: changed sample rate to 44422 Hz xcb_xv debug: display is visible xcb_xv debug: display is visible xcb_xv debug: display is visible xcb_xv debug: display is visible main debug: auto hiding mouse cursor pulse debug: changed sample rate to 44336 Hz xcb_xv debug: display is visible xcb_xv debug: display is visible xcb_xv debug: display is visible main debug: auto hiding mouse cursor I have had issues with VLC in the past- the audio quality was extremely crackly, as if the headphone jack was plugged in only half way, and the sounds were extremely sharp and caused my speakers to make a ringing/vibrating noise... It would eventually start working after I messed around with the audio settings, but it happened every restart. I eventually switched to SMPlayer, but now I need some of the features that VLC offers, but I still can't use VLC. At this point, the audio can not be heard at all, and the method I used before, messing around with the audio settings, isn't getting me anywhere. (note, I reposted this on VideoLan's forums, link is here: http://forum.videolan.org/viewtopic.php?f=13&t=104726) Please let me know if you need more information, or are confused by something I posted! Thanks!

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  • Keeping the meshes "thickness" the same when scaling an object

    - by user1806687
    I've been bashing my head for the past couple of weeks trying to find a way to help me accomplish, on first look very easy task. So, I got this one object currently made out of 5 cuboids (2 sides, 1 top, 1 bottom, 1 back), this is just for an example, later on there will be whole range of different set ups. Now, the thing is when the user chooses to scale the whole object this is what should happen: X scale: top and bottom cuboids should get scaled by a scale factor, sides should get moved so they are positioned just like they were before(in this case at both ends of top and bottom cuboids), back should get scaled so it fits like before(if I simply scale it by a scale factor it will leave gaps on each side). Y scale: sides should get scaled by a scale factor, top and bottom cuboid should get moved, and back should also get scaled. Z scale: sides, top and bottom cuboids should get scaled, back should get moved. Hope you can help, EDIT: So, I've decided to explain the situation once more, this time more detailed(hopefully). I've also made some pictures of how the scaling should look like, where is the problem and the wrong way of scaling. I this example I will be using a thick walled box, with one face missing, where each wall is made by a cuboid(but later on there will be diffrent shapes of objects, where a one of the face might be roundish, or triangle or even under some angle), scaling will be 2x on X axis. 1.This is how the default object without any scaling applied looks like: http://img856.imageshack.us/img856/4293/defaulttz.png 2.If I scale the whole object(all of the meshes) by some scale factor, the problem becomes that the "thickness" of the object walls also change(which I do not want): http://img822.imageshack.us/img822/9073/wrongwaytoscale.png 3.This is how the correct scaling should look like. Appropriate faces gets caled in this case where the scale is on X axis(top, bottom, back): http://imageshack.us/photo/my-images/163/rightwayxscale1.png/ 4.But the scale factor might not be the same for all object all of the times. In this case the back has to get scaled a bit more or it leaves gaps: http://imageshack.us/photo/my-images/9/problemwhenscaling.png/ 5.If everything goes well this is how the final object should look like: http://imageshack.us/photo/my-images/856/rightwayxscale2.png/ So, as you have might noticed there are quite a bit of things to look out when scaling. I am asking you, if any of you have any idea on how to accomplish this scaling. I have tried whole bunch of things, from scaling all of the object by the same scale factor, to subtracting and adding sizes to get the right size. But nothing I tried worked, if one mesh got scaled correctly then others didnt. Donwload the example object. English is not my first language, so I am really sorry if its hard to understand what I am saying.

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  • Trying to keep filled bars in a faceted plot

    - by John Horton
    Not sure what I'm doing wrong here. I have this plot: ggplot(data.PE5, aes(ybands,fill=factor(decide))) + geom_bar(position="dodge") which produces: Then I want to facet by a factor, creating two stacked plots w/ dodged, colored bars ggplot(data.PE5, aes(ybands,fill=factor(decide))) + geom_bar(position="dodge") + facet_grid(~group_label) However, I lose the factor-based coloring, which I want to keep:

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  • Using Live Data in Database Development Work

    - by Phil Factor
    Guest Editorial for Simple-Talk Newsletter... in which Phil Factor reacts with some exasperation when coming across a report that a majority of companies were still using financial and personal data for both developing and testing database applications. If you routinely test your development work using real production data that contains personal or financial information, you are probably being irresponsible, and at worst, risking a heavy financial penalty for your company. Surprisingly, over 80% of financial companies still do this. Plenty of data breaches and fraud have happened from the use of real data for testing, and a data breach is a nightmare for any organisation that suffers one. The cost of each data breach averages out at around $7.2 million in the US in notification, escalation, credit monitoring, fines, litigation, legal costs, and lost business due to customer churn, £1.9 million in the UK. 70% of data breaches are done from within the organisation. Real data can be exploited in a number of ways for malicious or criminal purposes. It isn't just the obvious use of items such as name and address, date of birth, social security number, and credit card and bank account numbers: Data can be exploited in many subtle ways, so there are excellent reasons to ensure that a high priority is given to the detection and prevention of any data breaches. You'll never successfully guess all the ways that real data can be exploited maliciously, or the ease with which it can be accessed. It would be silly to argue that developers never need access to a copy of the database containing live data. Developers sometimes need to track a bug that can only be replicated on the data from the live database. However, it has to be done in a very restrictive harness. The law makes no distinction between development and production databases when a data breach occurs, so the data has to be held with all appropriate security measures in place. In Europe, the use of personal data for testing requires the explicit consent of the people whose data is being held. There are federal standards such as GLBA, PCI DSS and HIPAA, and most US States have privacy legislation. The task of ensuring compliance and tight security in such circumstances is an expensive and time-consuming overhead. The developer is likely to suffer investigation if a data breach occurs, even if the company manages to stay in business. Ironically, the use of copies of live data isn't usually the most effective way to develop or test your data. Data is usually time-specific and isn't usually current by the time it is used for testing, Existing data doesn't help much for new functionality, and every time the data is refreshed from production, any test data is likely to be overwritten. Also, it is not always going to test all the 'edge' conditions that are likely to flush out bugs. You still have the task of simulating the dynamics of actual usage of the database, and here you have no alternative to creating 'spoofed' data. Because of the complexities of relational data, It used to be that there was no realistic alternative to developing and testing with live data. However, this is no longer the case. Real data can be obfuscated, or it can be created entirely from scratch. The latter process used to be impractical, now that there are plenty of third-party tools to choose from. The process of obfuscation isn't risk free. The process must access the live data, and the success of the obfuscation process has to be carefully monitored. Database data security isn't an exciting topic to you or I, but to a hacker it can be an all-consuming obsession, especially if there is financial or political gain involved. This is not the sort of adversary one would wish for and it is far better to accept, and work with, security restrictions that exist for using live data in database development work, especially when the tools exist to create large realistic database test data that can be better for several aspects of testing.

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  • Some Original Expressions

    - by Phil Factor
    Guest Editorial for Simple-Talk newsletterIn a guest editorial for the Simple-Talk Newsletter, Phil Factor wonders if we are still likely to find some more novel and unexpected ways of using the newer features of Transact SQL: or maybe in some features that have always been there! There can be a great deal of fun to be had in trying out recent features of SQL Expressions to see if  they provide new functionality.  It is surprisingly rare to find things that couldn’t be done before, but in a different   and more cumbersome way; but it is great to experiment or to read of someone else making that discovery.  One such recent feature is the ‘table value constructor’, or ‘VALUES constructor’, that managed to get into SQL Server 2008 from Standard SQL.  This allows you to create derived tables of up to 1000 rows neatly within select statements that consist of  lists of row values.  E.g. SELECT Old_Welsh, number FROM (VALUES ('Un',1),('Dou',2),('Tri',3),('Petuar',4),('Pimp',5),('Chwech',6),('Seith',7),('Wyth',8),('Nau',9),('Dec',10)) AS WelshWordsToTen (Old_Welsh, number) These values can be expressions that return single values, including, surprisingly, subqueries. You can use this device to create views, or in the USING clause of a MERGE statement. Joe Celko covered  this here and here.  It can become extraordinarily handy to use once one gets into the way of thinking in these terms, and I’ve rewritten a lot of routines to use the constructor, but the old way of using UNION can be used the same way, but is a little slower and more long-winded. The use of scalar SQL subqueries as an expression in a VALUES constructor, and then applied to a MERGE, has got me thinking. It looks very clever, but what use could one put it to? I haven’t seen anything yet that couldn’t be done almost as  simply in SQL Server 2000, but I’m hopeful that someone will come up with a way of solving a tricky problem, just in the same way that a freak of the XML syntax forever made the in-line  production of delimited lists from an expression easy, or that a weird XML pirouette could do an elegant  pivot-table rotation. It is in this sort of experimentation where the community of users can make a real contribution. The dissemination of techniques such as the Number, or Tally table, or the unconventional ways that the UPDATE statement can be used, has been rapid due to articles and blogs. However, there is plenty to be done to explore some of the less obvious features of Transact SQL. Even some of the features introduced into SQL Server 2000 are hardly well-known. Certain operations on data are still awkward to perform in Transact SQL, but we mustn’t, I think, be too ready to state that certain things can only be done in the application layer, or using a CLR routine. With the vast array of features in the product, and with the tools that surround it, I feel that there is generally a way of getting tricky things done. Or should we just stick to our lasts and push anything difficult out into procedural code? I’d love to know your views.

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  • Informed TDD &ndash; Kata &ldquo;To Roman Numerals&rdquo;

    - by Ralf Westphal
    Originally posted on: http://geekswithblogs.net/theArchitectsNapkin/archive/2014/05/28/informed-tdd-ndash-kata-ldquoto-roman-numeralsrdquo.aspxIn a comment on my article on what I call Informed TDD (ITDD) reader gustav asked how this approach would apply to the kata “To Roman Numerals”. And whether ITDD wasn´t a violation of TDD´s principle of leaving out “advanced topics like mocks”. I like to respond with this article to his questions. There´s more to say than fits into a commentary. Mocks and TDD I don´t see in how far TDD is avoiding or opposed to mocks. TDD and mocks are orthogonal. TDD is about pocess, mocks are about structure and costs. Maybe by moving forward in tiny red+green+refactor steps less need arises for mocks. But then… if the functionality you need to implement requires “expensive” resource access you can´t avoid using mocks. Because you don´t want to constantly run all your tests against the real resource. True, in ITDD mocks seem to be in almost inflationary use. That´s not what you usually see in TDD demonstrations. However, there´s a reason for that as I tried to explain. I don´t use mocks as proxies for “expensive” resource. Rather they are stand-ins for functionality not yet implemented. They allow me to get a test green on a high level of abstraction. That way I can move forward in a top-down fashion. But if you think of mocks as “advanced” or if you don´t want to use a tool like JustMock, then you don´t need to use mocks. You just need to stand the sight of red tests for a little longer ;-) Let me show you what I mean by that by doing a kata. ITDD for “To Roman Numerals” gustav asked for the kata “To Roman Numerals”. I won´t explain the requirements again. You can find descriptions and TDD demonstrations all over the internet, like this one from Corey Haines. Now here is, how I would do this kata differently. 1. Analyse A demonstration of TDD should never skip the analysis phase. It should be made explicit. The requirements should be formalized and acceptance test cases should be compiled. “Formalization” in this case to me means describing the API of the required functionality. “[D]esign a program to work with Roman numerals” like written in this “requirement document” is not enough to start software development. Coding should only begin, if the interface between the “system under development” and its context is clear. If this interface is not readily recognizable from the requirements, it has to be developed first. Exploration of interface alternatives might be in order. It might be necessary to show several interface mock-ups to the customer – even if that´s you fellow developer. Designing the interface is a task of it´s own. It should not be mixed with implementing the required functionality behind the interface. Unfortunately, though, this happens quite often in TDD demonstrations. TDD is used to explore the API and implement it at the same time. To me that´s a violation of the Single Responsibility Principle (SRP) which not only should hold for software functional units but also for tasks or activities. In the case of this kata the API fortunately is obvious. Just one function is needed: string ToRoman(int arabic). And it lives in a class ArabicRomanConversions. Now what about acceptance test cases? There are hardly any stated in the kata descriptions. Roman numerals are explained, but no specific test cases from the point of view of a customer. So I just “invent” some acceptance test cases by picking roman numerals from a wikipedia article. They are supposed to be just “typical examples” without special meaning. Given the acceptance test cases I then try to develop an understanding of the problem domain. I´ll spare you that. The domain is trivial and is explain in almost all kata descriptions. How roman numerals are built is not difficult to understand. What´s more difficult, though, might be to find an efficient solution to convert into them automatically. 2. Solve The usual TDD demonstration skips a solution finding phase. Like the interface exploration it´s mixed in with the implementation. But I don´t think this is how it should be done. I even think this is not how it really works for the people demonstrating TDD. They´re simplifying their true software development process because they want to show a streamlined TDD process. I doubt this is helping anybody. Before you code you better have a plan what to code. This does not mean you have to do “Big Design Up-Front”. It just means: Have a clear picture of the logical solution in your head before you start to build a physical solution (code). Evidently such a solution can only be as good as your understanding of the problem. If that´s limited your solution will be limited, too. Fortunately, in the case of this kata your understanding does not need to be limited. Thus the logical solution does not need to be limited or preliminary or tentative. That does not mean you need to know every line of code in advance. It just means you know the rough structure of your implementation beforehand. Because it should mirror the process described by the logical or conceptual solution. Here´s my solution approach: The arabic “encoding” of numbers represents them as an ordered set of powers of 10. Each digit is a factor to multiply a power of ten with. The “encoding” 123 is the short form for a set like this: {1*10^2, 2*10^1, 3*10^0}. And the number is the sum of the set members. The roman “encoding” is different. There is no base (like 10 for arabic numbers), there are just digits of different value, and they have to be written in descending order. The “encoding” XVI is short for [10, 5, 1]. And the number is still the sum of the members of this list. The roman “encoding” thus is simpler than the arabic. Each “digit” can be taken at face value. No multiplication with a base required. But what about IV which looks like a contradiction to the above rule? It is not – if you accept roman “digits” not to be limited to be single characters only. Usually I, V, X, L, C, D, M are viewed as “digits”, and IV, IX etc. are viewed as nuisances preventing a simple solution. All looks different, though, once IV, IX etc. are taken as “digits”. Then MCMLIV is just a sum: M+CM+L+IV which is 1000+900+50+4. Whereas before it would have been understood as M-C+M+L-I+V – which is more difficult because here some “digits” get subtracted. Here´s the list of roman “digits” with their values: {1, I}, {4, IV}, {5, V}, {9, IX}, {10, X}, {40, XL}, {50, L}, {90, XC}, {100, C}, {400, CD}, {500, D}, {900, CM}, {1000, M} Since I take IV, IX etc. as “digits” translating an arabic number becomes trivial. I just need to find the values of the roman “digits” making up the number, e.g. 1954 is made up of 1000, 900, 50, and 4. I call those “digits” factors. If I move from the highest factor (M=1000) to the lowest (I=1) then translation is a two phase process: Find all the factors Translate the factors found Compile the roman representation Translation is just a look-up. Finding, though, needs some calculation: Find the highest remaining factor fitting in the value Remember and subtract it from the value Repeat with remaining value and remaining factors Please note: This is just an algorithm. It´s not code, even though it might be close. Being so close to code in my solution approach is due to the triviality of the problem. In more realistic examples the conceptual solution would be on a higher level of abstraction. With this solution in hand I finally can do what TDD advocates: find and prioritize test cases. As I can see from the small process description above, there are two aspects to test: Test the translation Test the compilation Test finding the factors Testing the translation primarily means to check if the map of factors and digits is comprehensive. That´s simple, even though it might be tedious. Testing the compilation is trivial. Testing factor finding, though, is a tad more complicated. I can think of several steps: First check, if an arabic number equal to a factor is processed correctly (e.g. 1000=M). Then check if an arabic number consisting of two consecutive factors (e.g. 1900=[M,CM]) is processed correctly. Then check, if a number consisting of the same factor twice is processed correctly (e.g. 2000=[M,M]). Finally check, if an arabic number consisting of non-consecutive factors (e.g. 1400=[M,CD]) is processed correctly. I feel I can start an implementation now. If something becomes more complicated than expected I can slow down and repeat this process. 3. Implement First I write a test for the acceptance test cases. It´s red because there´s no implementation even of the API. That´s in conformance with “TDD lore”, I´d say: Next I implement the API: The acceptance test now is formally correct, but still red of course. This will not change even now that I zoom in. Because my goal is not to most quickly satisfy these tests, but to implement my solution in a stepwise manner. That I do by “faking” it: I just “assume” three functions to represent the transformation process of my solution: My hypothesis is that those three functions in conjunction produce correct results on the API-level. I just have to implement them correctly. That´s what I´m trying now – one by one. I start with a simple “detail function”: Translate(). And I start with all the test cases in the obvious equivalence partition: As you can see I dare to test a private method. Yes. That´s a white box test. But as you´ll see it won´t make my tests brittle. It serves a purpose right here and now: it lets me focus on getting one aspect of my solution right. Here´s the implementation to satisfy the test: It´s as simple as possible. Right how TDD wants me to do it: KISS. Now for the second equivalence partition: translating multiple factors. (It´a pattern: if you need to do something repeatedly separate the tests for doing it once and doing it multiple times.) In this partition I just need a single test case, I guess. Stepping up from a single translation to multiple translations is no rocket science: Usually I would have implemented the final code right away. Splitting it in two steps is just for “educational purposes” here. How small your implementation steps are is a matter of your programming competency. Some “see” the final code right away before their mental eye – others need to work their way towards it. Having two tests I find more important. Now for the next low hanging fruit: compilation. It´s even simpler than translation. A single test is enough, I guess. And normally I would not even have bothered to write that one, because the implementation is so simple. I don´t need to test .NET framework functionality. But again: if it serves the educational purpose… Finally the most complicated part of the solution: finding the factors. There are several equivalence partitions. But still I decide to write just a single test, since the structure of the test data is the same for all partitions: Again, I´m faking the implementation first: I focus on just the first test case. No looping yet. Faking lets me stay on a high level of abstraction. I can write down the implementation of the solution without bothering myself with details of how to actually accomplish the feat. That´s left for a drill down with a test of the fake function: There are two main equivalence partitions, I guess: either the first factor is appropriate or some next. The implementation seems easy. Both test cases are green. (Of course this only works on the premise that there´s always a matching factor. Which is the case since the smallest factor is 1.) And the first of the equivalence partitions on the higher level also is satisfied: Great, I can move on. Now for more than a single factor: Interestingly not just one test becomes green now, but all of them. Great! You might say, then I must have done not the simplest thing possible. And I would reply: I don´t care. I did the most obvious thing. But I also find this loop very simple. Even simpler than a recursion of which I had thought briefly during the problem solving phase. And by the way: Also the acceptance tests went green: Mission accomplished. At least functionality wise. Now I´ve to tidy up things a bit. TDD calls for refactoring. Not uch refactoring is needed, because I wrote the code in top-down fashion. I faked it until I made it. I endured red tests on higher levels while lower levels weren´t perfected yet. But this way I saved myself from refactoring tediousness. At the end, though, some refactoring is required. But maybe in a different way than you would expect. That´s why I rather call it “cleanup”. First I remove duplication. There are two places where factors are defined: in Translate() and in Find_factors(). So I factor the map out into a class constant. Which leads to a small conversion in Find_factors(): And now for the big cleanup: I remove all tests of private methods. They are scaffolding tests to me. They only have temporary value. They are brittle. Only acceptance tests need to remain. However, I carry over the single “digit” tests from Translate() to the acceptance test. I find them valuable to keep, since the other acceptance tests only exercise a subset of all roman “digits”. This then is my final test class: And this is the final production code: Test coverage as reported by NCrunch is 100%: Reflexion Is this the smallest possible code base for this kata? Sure not. You´ll find more concise solutions on the internet. But LOC are of relatively little concern – as long as I can understand the code quickly. So called “elegant” code, however, often is not easy to understand. The same goes for KISS code – especially if left unrefactored, as it is often the case. That´s why I progressed from requirements to final code the way I did. I first understood and solved the problem on a conceptual level. Then I implemented it top down according to my design. I also could have implemented it bottom-up, since I knew some bottom of the solution. That´s the leaves of the functional decomposition tree. Where things became fuzzy, since the design did not cover any more details as with Find_factors(), I repeated the process in the small, so to speak: fake some top level, endure red high level tests, while first solving a simpler problem. Using scaffolding tests (to be thrown away at the end) brought two advantages: Encapsulation of the implementation details was not compromised. Naturally private methods could stay private. I did not need to make them internal or public just to be able to test them. I was able to write focused tests for small aspects of the solution. No need to test everything through the solution root, the API. The bottom line thus for me is: Informed TDD produces cleaner code in a systematic way. It conforms to core principles of programming: Single Responsibility Principle and/or Separation of Concerns. Distinct roles in development – being a researcher, being an engineer, being a craftsman – are represented as different phases. First find what, what there is. Then devise a solution. Then code the solution, manifest the solution in code. Writing tests first is a good practice. But it should not be taken dogmatic. And above all it should not be overloaded with purposes. And finally: moving from top to bottom through a design produces refactored code right away. Clean code thus almost is inevitable – and not left to a refactoring step at the end which is skipped often for different reasons.   PS: Yes, I have done this kata several times. But that has only an impact on the time needed for phases 1 and 2. I won´t skip them because of that. And there are no shortcuts during implementation because of that.

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