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  • Project management and bundling dependencies

    - by Joshua
    I've been looking for ways to learn about the right way to manage a software project, and I've stumbled upon the following blog post. I've learned some of the things mentioned the hard way, others make sense, and yet others are still unclear to me. To sum up, the author lists a bunch of features of a project and how much those features contribute to a project's 'suckiness' for a lack of a better term. You can find the full article here: http://spot.livejournal.com/308370.html In particular, I don't understand the author's stance on bundling dependencies with your project. These are: == Bundling == Your source only comes with other code projects that it depends on [ +20 points of FAIL ] Why is this a problem, (especially given the last point)? If your source code cannot be built without first building the bundled code bits [ +10 points of FAIL ] Doesn't this necessarily have to be the case for software built against 3rd party libs? Your code needs that other code to be compiled into its library before the linker can work? If you have modified those other bundled code bits [ +40 points of FAIL ] If this is necessary for your project, then it naturally follows that you've bundled said code with yours. If you want to customize a build of some lib,say WxWidgets, you'll have to edit that projects build scripts to bulid the library that you want. Subsequently, you'll have to publish those changes to people who wish to build your code, so why not use a high level make script with the params already written in, and distribute that? Furthermore, (especially in a windows env) if your code base is dependent on a particular version of a lib (that you also need to custom compile for your project) wouldn't it be easier to give the user the code yourself (because in this case, it is unlikely that the user will already have the correct version installed)? So how would you respond to these comments, and what points may I be failing to take into consideration? Would you agree or disagree with the author's take (or mine), and why?

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  • Summarising grouped records in a dataframe in R (...again)

    - by monch1962
    Hello all, (I tried to ask this question earlier today, but later realised I over-simplified the question; the answers I received were correct, but I couldn't use them because of my over-simplification of the problem in the original question. Here's my 2nd attempt...) I have a data frame in R that looks like: "Timestamp", "Source", "Target", "Length", "Content" 0.1 , P1 , P2 , 5 , "ABCDE" 0.2 , P1 , P2 , 3 , "HIJ" 0.4 , P1 , P2 , 4 , "PQRS" 0.5 , P2 , P1 , 2 , "ZY" 0.9 , P2 , P1 , 4 , "SRQP" 1.1 , P1 , P2 , 1 , "B" 1.6 , P1 , P2 , 3 , "DEF" 2.0 , P2 , P1 , 3 , "IJK" ... and I want to convert this to: "StartTime", "EndTime", "Duration", "Source", "Target", "Length", "Content" 0.1 , 0.4 , 0.3 , P1 , P2 , 12 , "ABCDEHIJPQRS" 0.5 , 0.9 , 0.4 , P2 , P1 , 6 , "ZYSRQP" 1.1 , 1.6 , 0.5 , P1 , P2 , 4 , "BDEF" ... Trying to put this into English, I want to group consecutive records with the same 'Source' and 'Target' together, then print out a single record per group showing the StartTime, EndTime & Duration (=EndTime-StartTime) for that group, along with the sum of the Lengths for that group, and a concatenation of the Content (which will all be strings) in that group. The TimeOffset values will always increase throughout the data frame. I had a look at melt/recast and have a feeling that it could be used to solve the problem, but couldn't get my head around the documentation. I suspect it's possible to do this within R, but I really don't know where to start. In a pinch I could export the data frame out and do it in e.g. Python, but I'd prefer to stay within R if possible. Thanks in advance for any assistance you can provide

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  • MySQL get point in time totals from related tables

    - by batfastad
    Hi everyone We have an order book and invoicing system and I've been tasked with trying to output monthly rolling totals from these tables. But I don't know really where to start with this. I think there's some SQL syntax that I don't even know about yet. I'm familiar with INNER/LEFT/JOINS and GROUP BY etc but grouping by date is confusing since I don't know how to limit the data to only the current date that's being grouped by at that point. I think this will involve joining the tables to themselves or possibly a sub-select. I always thought it best to avoid sub-selects apart from when absolutely necessary. Basically the system has 3 tables orders: order_id, currency, order_stamp orders_lines: order_line_id, invoice_id, order_id, price invoices: invoice_id, invoice_stamp order_stamp and invoice_stamp are UTC unix timestamps stored as integers, not MySQL timestamps. I'm trying to get a listing by year/month showing the total of current unbilled orders (sum of price), at that point in time. Current orders are ones where order_stamp is less than or equal to 00:00 on the 1st of the month. Unbilled orders are ones where invoice_stamp is null or invoice_stamp is greater than 00:00 on the 1st of the month. At that point in time there may not be a related invoice yet and invoice_id might be null. Anyone got any suggestions on what I should join to what and what I need to group by? Cheers, B

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  • Combine XML elements with xsl

    - by mpenrow
    I have the following xml: <RowSet> <Row> <Number>12345</Number> <Quantity>42</Quantity> </Row> <Row> <Number>12345</Number> <Quantity>12</Quantity> </Row> <Row> <Number>54321</Number> <Quantity>37</Quantity> </Row> </RowSet> I want to use an xsl to combine the elements with the same Number and the resulting should sum the Quantity elements. So the output should look like this: <RowSet> <Row> <Number>12345</Number> <Quantity>64</Quantity> </Row> <Row> <Number>54321</Number> <Quantity>37</Quantity> </Row> </RowSet>

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  • What is the optimum way to select the most dissimilar individuals from a population?

    - by Aaron D
    I have tried to use k-means clustering to select the most diverse markers in my population, for example, if we want to select 100 lines I cluster the whole population to 100 clusters then select the closest marker to the centroid from each cluster. The problem with my solution is it takes too much time (probably my function needs optimization), especially when the number of markers exceeds 100000. So, I will appreciate it so much if anyone can show me a new way to select markers that maximize diversity in my population and/or help me optimize my function to make it work faster. Thank you # example: library(BLR) data(wheat) dim(X) mdf<-mostdiff(t(X), 100,1,nstart=1000) Here is the mostdiff function that i used: mostdiff <- function(markers, nClust, nMrkPerClust, nstart=1000) { transposedMarkers <- as.array(markers) mrkClust <- kmeans(transposedMarkers, nClust, nstart=nstart) save(mrkClust, file="markerCluster.Rdata") # within clusters, pick the markers that are closest to the cluster centroid # turn the vector of which markers belong to which clusters into a list nClust long # each element of the list is a vector of the markers in that cluster clustersToList <- function(nClust, clusters) { vecOfCluster <- function(whichClust, clusters) { return(which(whichClust == clusters)) } return(apply(as.array(1:nClust), 1, vecOfCluster, clusters)) } pickCloseToCenter <- function(vecOfCluster, whichClust, transposedMarkers, centers, pickHowMany) { clustSize <- length(vecOfCluster) # if there are fewer than three markers, the center is equally distant from all so don't bother if (clustSize < 3) return(vecOfCluster[1:min(pickHowMany, clustSize)]) # figure out the distance (squared) between each marker in the cluster and the cluster center distToCenter <- function(marker, center){ diff <- center - marker return(sum(diff*diff)) } dists <- apply(transposedMarkers[vecOfCluster,], 1, distToCenter, center=centers[whichClust,]) return(vecOfCluster[order(dists)[1:min(pickHowMany, clustSize)]]) } }

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  • Update on: How to model random non-overlapping spheres of non-uniform size in a cube using Matlab?

    - by user3838079
    I am trying to use MATLAB for generating random locations for non-uniform size spheres (non-overlapping) in a cube. The for loop in the code below never seems to end. I don't know what am missing in the code. I have ran the code for no. of spheres (n) = 10; dims = [ 10 10 10 ] function [ c r ] = randomSphere( dims ) % creating one sphere at random inside [0..dims(1)]x[0..dims(2)]x... % radius and center coordinates are sampled from a uniform distribution % over the relevant domain. % output: c - center of sphere (vector cx, cy,... ) % r - radius of sphere (scalar) r = rand(1); % you might want to scale this w.r.t dims or other consideration c = r + rand( size(dims) )./( dims - 2*r ); % make sure sphere does not exceed boundaries function ovlp = nonOverlapping( centers, rads ) % check if several spheres with centers and rads overlap or not ovlp = false; if numel( rads ) == 1 return; % nothing to check for a single sphere end dst = sqrt( sum( bsxfun( @minus, permute( centers, [1 3 2] ),... permute( centers, [3 1 2] ) ).^2, 3) ); ovlp = dst >= bsxfun( @plus, rads, rads.' ); %' all distances must be smaller than r1+r2 ovlp = any( ovlp(:) ); % all must not overlap function [centers rads] = sampleSpheres( dims, n ) % dims is assumed to be a row vector of size 1-by-ndim % preallocate ndim = numel(dims); centers = zeros( n, ndim ); rads = zeros( n, 1 ); ii = 1; while ii <= n [centers(ii,:), rads(ii) ] = randomSphere( dims ); if nonOverlapping( centers(1:ii,:), rads(1:ii) ) ii = ii + 1; % accept and move on end end

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  • Can C++ do something like an ML case expression?

    - by Nathan Andrew Mullenax
    So, I've run into this sort of thing a few times in C++ where I'd really like to write something like case (a,b,c,d) of (true, true, _, _ ) => expr | (false, true, _, false) => expr | ... But in C++, I invariably end up with something like this: bool c11 = color1.count(e.first)>0; bool c21 = color2.count(e.first)>0; bool c12 = color1.count(e.second)>0; bool c22 = color2.count(e.second)>0; // no vertex in this edge is colored // requeue if( !(c11||c21||c12||c22) ) { edges.push(e); } // endpoints already same color // failure condition else if( (c11&&c12)||(c21&&c22) ) { results.push_back("NOT BICOLORABLE."); return true; } // nothing to do: nodes are already // colored and different from one another else if( (c11&&c22)||(c21&&c12) ) { } // first is c1, second is not set else if( c11 && !(c12||c22) ) { color2.insert( e.second ); } // first is c2, second is not set else if( c21 && !(c12||c22) ) { color1.insert( e.second ); } // first is not set, second is c1 else if( !(c11||c21) && c12 ) { color2.insert( e.first ); } // first is not set, second is c2 else if( !(c11||c21) && c22 ) { color1.insert( e.first ); } else { std::cout << "Something went wrong.\n"; } I'm wondering if there's any way to clean all of those if's and else's up, as it seems especially error prone. It would be even better if it were possible to get the compiler complain like SML does when a case expression (or statement in C++) isn't exhaustive. I realize this question is a bit vague. Maybe, in sum, how would one represent an exhaustive truth table with an arbitrary number of variables in C++ succinctly? Thanks in advance.

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  • jQuery resizable() dynamic maxWidth option

    - by Vitaliy Isikov
    I have 3 columns that are resizable. When one is made wider, the one to it's left is made smaller. Essentially there are only 2 handles. Left col and Mid col. So when Mid col is made thinner, Right col expands accordingly. All three of them are contained with a 900px parent div, so the sum of all three is always 900. They have max and min widths set statically. My issue is that if you take the left handle and move it all the way to the right you're still able to use the right handle and expand the mid col past the edge of the parent div. I thought of a way to solve that issue by writing up a function that checks the widths of the columns and then subtracts left and right columns from the parent div width, I called it mWid. This leaves me with the number I want to set as the maxWidth for Mid col. Now the issue is that mWid is not gettings updated for here "maxWidth: mWid" Here is what the function for the right handle looks like: $(function() { $("#midResizable").resizable({ handles: 'e', containment: '#container', maxWidth: mWid, // gets set once, but doesn't update! WHY? minWidth: 195, resize: function(event, ui) { contWidth = $('#container').width() newWidth = $(this).width() leftWidth = $('#leftResizable').width() rightWidth = $('#rightResizable').width() $("#rightResizable").css("width", (contWidth-15)-(newWidth)-(leftWidth)+"px"); checkWid() } }); }); function checkWid() { rightWidth = $('#rightResizable').width() leftWidth = $('#leftResizable').width() contWidth = $('#container').width() mWid = (contWidth-15)-(rightWidth)-(leftWidth) }

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  • convert an int to list of individual digitals more faster?

    - by user478514
    All, I want define an int(987654321) <= [9, 8, 7, 6, 5, 4, 3, 2, 1] convertor, if the length of int number < 9, for example 10 the list will be [0,0,0,0,0,0,0,1,0] , and if the length 9, for example 9987654321 , the list will be [9, 9, 8, 7, 6, 5, 4, 3, 2, 1] >>> i 987654321 >>> l [9, 8, 7, 6, 5, 4, 3, 2, 1] >>> z = [0]*(len(unit) - len(str(l))) >>> z.extend(l) >>> l = z >>> unit [100000000, 10000000, 1000000, 100000, 10000, 1000, 100, 10, 1] >>> sum([x*y for x,y in zip(l, unit)]) 987654321 >>> int("".join([str(x) for x in l])) 987654321 >>> l1 = [int(x) for x in str(i)] >>> z = [0]*(len(unit) - len(str(l1))) >>> z.extend(l1) >>> l1 = z >>> l1 [9, 8, 7, 6, 5, 4, 3, 2, 1] >>> a = [i//x for x in unit] >>> b = [a[x] - a[x-1]*10 for x in range(9)] >>> if len(b) = len(a): b[0] = a[0] # fix the a[-1] issue >>> b [9, 8, 7, 6, 5, 4, 3, 2, 1] I tested above solutions but found those may not faster/simple enough than I want and may have a length related bug inside, anyone may share me a better solution for this kinds convertion? Thanks!

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  • Performing a SVD on tweets. Memory problem

    - by plotti
    I have generated a huge csv file as an output from my pos tagging and stemming. It looks like this: word1, word2, word3, ..., word14400 person1 1 2 0 1 person2 0 0 1 0 ... person650 It contains the word counts for each person. Like this I am getting characteristic vectors for each person. I want to run a SVD on this beast, but it seems the matrix is too big to be held in memory to perform the operation. My quesion is: should i reduce the column size by removing words which have a column sum of for example 1, which means that they have been used only once. Do I bias the data too much with this attempt? I tried the rapidminer attempt, by loading the csv into the db. and then sequentially reading it in with batches for processing, like rapidminer proposes. But Mysql can't store that many columns in a table. If i transpose the data, and then retranspose it on import it also takes ages.... -- So in general I am asking for advice how to perform a svd on such a corpus.

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  • Silverlight 4 XAML Collections

    - by mattduffield
    Hello, I have authored some custom classes that I would like to create using XAML: <Grid Width="300" Height="300"> <l:DashboardTable> <l:DashboardTable.DashboardTableQuery> <dq:DashboardTableQuery ConnectionString="Data Source=bunkerhill;Initial Catalog=emgov_data;User Id=emgovadmin;Password=p@$$word;" Query="select datename(month, cr_tb_DateDue) AS Month, sum(cr_tb_AmountTransaction) AS Total from cr_tb_transactionbill where Year(cr_tb_DateDue) = 2005 and Month(cr_tb_DateDue) IN (1,2,3,4) group by datename(month, cr_tb_DateDue)" > <dq:DashboardTableQuery.DataColumns> <dq:DataColumn ColumnName="Month" ColumnOrder="0" Label="Month" /> <dq:DataColumn ColumnName="Total" ColumnOrder="1" Label="Total" /> </dq:DashboardTableQuery.DataColumns> </dq:DashboardTableQuery> </l:DashboardTable.DashboardTableQuery> </l:DashboardTable> </Grid> The problem is that I get a XamlParseException when I try to run this XAML. I have determined it is when it gets to the dq:DataColumn element. It seems like this is only happening when I have a property that then has a collection and then several items in the collection that I am getting this issue. Has any encountered anything similar? I am try to achieve this all in XAML declaratively.

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  • Javascript Recursion

    - by rpophessagr
    I have an ajax call and would like to recall it once I finish parsing and animating the result into the page. And that's where I'm getting stuck. I was able to recall the function, but it seems to not take into account the delays in the animation. i.e. The console keeps outputting the values at a wild pace. I thought setInterval might help with the interval being the sum of the length of my delays, but I can't get that to work... function loadEm(){ var result=new Array(); $.getJSON("jsonCall.php",function(results){ $.each(results, function(i, res){ rand = (Math.floor(Math.random()*11)*1000)+2000; fullRand += rand; console.log(fullRand); $("tr:first").delay(rand).queue(function(next) { doStuff(res); next(); }); }); var int=self.setInterval("loadEm()",fullRand); }); } });

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  • Modify passed, nested dict/list

    - by Gerenuk
    I was thinking of writing a function to normalize some data. A simple approach is def normalize(l, aggregate=sum, norm_by=operator.truediv): aggregated=aggregate(l) for i in range(len(l)): l[i]=norm_by(l[i], aggregated) l=[1,2,3,4] normalize(l) l -> [0.1, 0.2, 0.3, 0.4] However for nested lists and dicts where I want to normalize over an inner index this doesnt work. I mean I'd like to get l=[[1,100],[2,100],[3,100],[4,100]] normalize(l, ?? ) l -> [[0.1,100],[0.2,100],[0.3,100],[0.4,100]] Any ideas how I could implement such a normalize function? Maybe it would be crazy cool to write normalize(l[...][0]) Is it possible to make this work?? Or any other ideas? Also not only lists but also dict could be nested. Hmm... EDIT: I just found out that numpy offers such a syntax (for lists however). Anyone know how I would implement the ellipsis trick myself?

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  • How to optimize a postgreSQL server for a "write once, read many"-type infrastructure ?

    - by mhu
    Greetings, I am working on a piece of software that logs entries (and related tagging) in a PostgreSQL database for storage and retrieval. We never update any data once it has been inserted; we might remove it when the entry gets too old, but this is done at most once a day. Stored entries can be retrieved by users. The insertion of new entries can happen rather fast and regularly, thus the database will commonly hold several millions elements. The tables used are pretty simple : one table for ids, raw content and insertion date; and one table storing tags and their values associated to an id. User search mostly concern tags values, so SELECTs usually consist of JOIN queries on ids on the two tables. To sum it up : 2 tables Lots of INSERT no UPDATE some DELETE, once a day at most some user-generated SELECT with JOIN huge data set What would an optimal server configuration (software and hardware, I assume for example that RAID10 could help) be for my PostgreSQL server, given these requirements ? By optimal, I mean one that allows SELECT queries taking a reasonably little amount of time. I can provide more information about the current setup (like tables, indexes ...) if needed.

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  • how to use a PHP Constant that gets pulled from a database

    - by Ronedog
    Can you read out the name of a PHP constant from a database and use it inside of a php variable, to display the value of the constant for use in a menu? For example here's what I'm trying to accomplish In SQL: select menu_name AS php_CONSTANT where menu_id=1 the value returned would be L_HOME which is the name of a CONSTANT in a php config page. The php config page looks like this define('L_HOME','Home'); and gets loaded before the database call. The php usage would be $db_returned_constant which has a value of L_HOME that came from the db call, then I would place this into a string such as $string = '<ul><li>' . $db_returned_constant . '</li></ul>' and thus return a string that looks like $string = '<ul><li><a href="#" onclick="path_from_db">Home</a></li></ul>'. To sum up what I'm trying to do Load a config file based on the language preference query the db to return the menu name, which is the name of a CONSTANT in the config file loaded in step one, and also retrieve the menu_link which is used in the "onclick" event. Use a php variable to hold the name of the CONSTANT Place the variable into a string that gets echo'd out to create the menu displaying the value of the CONSTANT. I hope this makes enough sense...is it even possible to use a constant like this? Thanks.

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  • How to check a file saving is complete using Python?

    - by indrajithk
    I am trying to automate a downloading process. In this I want to know, whether a particular file's save is completed or not. The scenario is like this. Open a site address using either Chrome or Firefox (any browser) Save the page to disk using 'Crtl + S' (I work on windows) Now if the page is very big, then it takes few seconds to save. I want to parse the html once the save is complete. Since I don't have control on the browser save functionality, I don't know whether the save has completed or not. One idea I thought, is to get the md5sum of the file using a while loop, and check against the previous one calculated, and continue the while loop till the md5 sum from the previous and current one matches. This doesn't works I guess, as it seems browser first attempts to save the file in a tmp file and then copies the content to the specified file (or just renames the file). Any ideas? I use python for the automation, hence any idea which can be implemented using python is welcome. Thanks Indrajith

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  • Basic question in XSL regarding preceding text

    - by Rachel
    I am new to XSL and i have a basic question on the context of using preceding text. My template match is on the text node. I am iterating over an xml file and within my for loop i am trying to take the preceding text of the text node. Unfortunately preceding::text() is not working if i use it within a for loop. I want to use it within the for loop but how can do it? <xsl:template match="text()"> <xsl:variable name="this" as="text()" select="."/> <xsl:for-each select="$input[@id = generate-id(current())]"> <xsl:variable name="preText" as="xsd:integer" select="sum(preceding::text()[. >> //*[@id=@name]]/string-length(.))"/> ... ... </xsl:for-each> </xsl:template>

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  • Matlab fft function

    - by CTZStef
    The code below is from the Matlab 2011a help about fft function. I think there is a problem here : why do they multiply t(1:50) by Fs, and then say it's time in millisecond ? Certainly, it happens to be true in this very particular case, but change the value of Fs to, say, 2000, and it won't work anymore, obviously because of this factor of 2. Right ? Quite misleading, isn't it ? What do I miss ? Fs = 1000; % Sampling frequency T = 1/Fs; % Sample time L = 1000; % Length of signal t = (0:L-1)*T; % Time vector % Sum of a 50 Hz sinusoid and a 120 Hz sinusoid x = 0.7*sin(2*pi*50*t) + sin(2*pi*120*t); y = x + 2*randn(size(t)); % Sinusoids plus noise plot(Fs*t(1:50),y(1:50)) title('Signal Corrupted with Zero-Mean Random Noise') xlabel('time (milliseconds)') Clearer with this : fs = 2000; % Sampling frequency T = 1 / fs; % Sample time L = 1000; % Length of signal t2 = (0:L-1)*T; % Time vector f = 50; % signal frequency s2 = sin(2*pi*f*t2); figure, plot(fs*t2(1:50),s2(1:50)); % NOT good figure, plot(t2(1:50),s2(1:50)); % good

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  • Is there a reason why SSIS significantly slows down after a few minutes?

    - by Mark
    I'm running a fairly substantial SSIS package against SQL 2008 - and I'm getting the same results both in my dev environment (Win7-x64 + SQL-x64-Developer) and the production environment (Server 2008 x64 + SQL Std x64). The symptom is that initial data loading screams at between 50K - 500K records per second, but after a few minutes the speed drops off dramatically and eventually crawls embarrasingly slowly. The database is in Simple recovery model, the target tables are empty, and all of the prerequisites for minimally logged bulk inserts are being met. The data flow is a simple load from a RAW input file to a schema-matched table (i.e. no complex transforms of data, no sorting, no lookups, no SCDs, etc.) The problem has the following qualities and resiliences: Problem persists no matter what the target table is. RAM usage is lowish (45%) - there's plenty of spare RAM available for SSIS buffers or SQL Server to use. Perfmon shows buffers are not spooling, disk response times are normal, disk availability is high. CPU usage is low (hovers around 25% shared between sqlserver.exe and DtsDebugHost.exe) Disk activity primarily on TempDB.mdf, but I/O is very low (< 600 Kb/s) OLE DB destination and SQL Server Destination both exhibit this problem. To sum it up, I expect either disk, CPU or RAM to be exhausted before the package slows down, but instead its as if the SSIS package is taking an afternoon nap. SQL server remains responsive to other queries, and I can't find any performance counters or logged events that betray the cause of the problem. I'll gratefully reward any reasonable answers / suggestions.

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  • Trying to edit an entity with data from dropdowns in MVC...

    - by user598352
    Hello! I'm having trouble getting my head around sending multiple models to a view in mvc. My problem is the following. Using EF4 I have a table with attributes organised by category. Couldn't post an image :-( [Have a table called attributes (AttributeTitle, AttributeName, CategoryID) connected to a table called Category (CategoryTitle).] What I want to do is be able to edit an attribute entity and have a dropdown of categories to choose from. I tried to make a custom viewmodel public class AttributeViewModel { public AttributeViewModel() { } public Attribute Attribute { get; set; } public IQueryable<Category> AllCategories { get; set; } } But it just ended up being a mess. <div class="editor-field"> <%: Html.DropDownList("Category", new SelectList((IEnumerable)Model.AllCategories, "CategoryID", "CategoryName")) %> </div> I was getting it back to the controller... [HttpPost] public ActionResult Edit(int AttributeID, FormCollection formcollection) { var _attribute = ProfileDB.GetAttribute(AttributeID); int _selcategory = Convert.ToInt32(formcollection["Category"]); _attribute.CategoryID = (int)_selcategory; try { UpdateModel(_attribute); (<---Error here) ProfileDB.SaveChanges(); return RedirectToAction("Index"); } catch (Exception e) { return View(_attribute); } } I've debugged the code and my _attribute looks correct and _attribute.CategoryID = (int)_selcategory updates the model, but then I get the error. Somewhere here I thought that there should be a cleaner way to do this, and that if I could only send two models to the view instead of having to make a custom viewmodel. To sum it up: I want to edit my attribute and have a dropdown of all of the available categories. Any help much appreciated!

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  • Absence of property syntax in Java

    - by Vojislav Stojkovic
    C# has syntax for declaring and using properties. For example, one can declare a simple property, like this: public int Size { get; set; } One can also put a bit of logic into the property, like this: public string SizeHex { get { return String.Format("{0:X}", Size); } set { Size = int.Parse(value, NumberStyles.HexNumber); } } Regardless of whether it has logic or not, a property is used in the same way as a field: int fileSize = myFile.Size; I'm no stranger to either Java or C# -- I've used both quite a lot and I've always missed having property syntax in Java. I've read in this question that "it's highly unlikely that property support will be added in Java 7 or perhaps ever", but frankly I find it too much work to dig around in discussions, forums, blogs, comments and JSRs to find out why. So my question is: can anyone sum up why Java isn't likely to get property syntax? Is it because it's not deemed important enough when compared to other possible improvements? Are there technical (e.g. JVM-related) limitations? Is it a matter of politics? (e.g. "I've been coding in Java for 50 years now and I say we don't need no steenkin' properties!") Is it a case of bikeshedding?

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  • Algorithm: Find smallest subset containing K 0's

    - by Vishal
    I have array of 1's and 0's only. Now I want to find contiguous subset/subarray which contains at least K 0's. Example Array is 1 1 0 1 1 0 1 1 0 0 0 0 1 0 1 1 0 0 0 1 1 0 0 1 0 0 0 and K(6) should be 0 0 1 0 1 1 0 0 0 or 0 0 0 0 1 0 1 1 0.... My Solution Array: 1 1 0 1 1 0 1 1 0 0 0 0 1 0 1 1 0 0 0 1 1 0 0 Index: 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 Sum: 1 2 2 3 4 4 5 6 6 6 6 6 7 7 8 9 9 9 9 10 11 11 11 Diff(I-S): 0 0 1 1 1 2 2 2 3 4 5 6 6 7 7 7 8 9 10 10 10 11 12 For K(6) Start with 9-15 = Store difference in diff. Next increase difference 8-15(Difference in index) 8-14(Compare Difference in index) So on keep moving to find element with least elements... I am looking for better algorithm for this solution.

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  • Communication with different social networks, strategy pattern?

    - by bclaessens
    Hi For the last few days I've been thinking how I can solve the following programming problem and find the ideal, flexible programming structure. (note: I'm using Flash as my platform technology but that shouldn't matter since I'm just looking for the ideal design pattern). Our Flash website has multiple situations in which it has to communicate with different social networks (Facebook, Netlog and Skyrock). Now, the communication strategy doesn't have to change multiple times over one "run". The strategy should be picked once (at launch time) for that session. The real problem is the way the communication works between each social network and our website. Some networks force us to ask for a token, others force us to use a webservice, yet another forces us to set up its communication through javascript. The problem becomes more complicated when our website has to run in each network's canvas. Which results in even more (different) ways of communicating. To sum up, our website has to work in the following cases: standalone on the campaign website url (user chooses their favourite network) communicate with netlog OR communicate with facebook OR communicate with skyrock run in a netlog canvas and log in automatically (website checks for netlog parameters) run in a facebook canvas and log in automatically (website checks for facebook params) run in a skyrock canvas and log in automatically (website checks for skyrock params) As you can see, our website needs 6 different ways to communicate with a social network. To be honest, the actual significant difference between all communication strategies is the way they have to connect to their individual network (as stated above in my example). Posting an image, make a comment, ... is the same whether it runs standalone or in the canvas url. WARNING: posting an image, posting a comment DOES differ from network to network. Should I use the strategy pattern and make 6 different communication strategies or is there a better way? An example would be great but isn't required ;) Thanks in advance

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  • Can knowing C actually hurt the code you write in higher level languages?

    - by Jurily
    The question seems settled, beaten to death even. Smart people have said smart things on the subject. To be a really good programmer, you need to know C. Or do you? I was enlightened twice this week. The first one made me realize that my assumptions don't go further than my knowledge behind them, and given the complexity of software running on my machine, that's almost non-existent. But what really drove it home was this Slashdot comment: The end result is that I notice the many naive ways in which traditional C "bare metal" programmers assume that higher level languages are implemented. They make bad "optimization" decisions in projects they influence, because they have no idea how a compiler works or how different a good runtime system may be from the naive macro-assembler model they understand. Then it hit me: C is just one more abstraction, like all others. Even the CPU itself is only an abstraction! I've just never seen it break, because I don't have the tools to measure it. I'm confused. Has my mind been mutilated beyond recovery, like Dijkstra said about BASIC? Am I living in a constant state of premature optimization? Is there hope for me, now that I realized I know nothing about anything? Is there anything to know, even? And why is it so fascinating, that everything I've written in the last five years might have been fundamentally wrong? To sum it up: is there any value in knowing more than the API docs tell me? EDIT: Made CW. Of course this also means now you must post examples of the interpreter/runtime optimizing better than we do :)

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  • negative values in integer programming model

    - by Lucia
    I'm new at using the glpk tool, and after writing a model for certain integer problem and running the solver (glpsol) i get negative values in some constraint that shouldn't be negative at all: No.Row name Activity Lower bound Upper bound 8 act[1] 0 -0 9 act[2] -3 -0 10 act[2] -2 -0 That constraint is defined like this: act{j in J}: sum{i in I} d[i,j] <= y[j]*m; where the sets and variables used are like this: param m, integer, 0; param n, integer, 0; set I := 1..m; set J := 1..n; var y{j in J}, binary; As the upper bound is negative, i think the problem may be in the y[j]*m parte, of the right side of the inequality.. perhaps something with the multiplication of binarys? or that the j in that side of the constrait is undefined? i dont know... i would be greatly grateful if someone can help me with this! :) and excuse for my bad english thanks in advance!

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