Search Results

Search found 22900 results on 916 pages for 'pascal case'.

Page 395/916 | < Previous Page | 391 392 393 394 395 396 397 398 399 400 401 402  | Next Page >

  • How can I peer into a Windows user's RDP session for support, where I initiate the support session?

    - by David Bullock
    I've used both WebEx and GoToAssist, but neither of them have a story to tell for 'unattended' access of a user's desktop unless the user is using the machine's primary console. Unattended in the sense that they phone me and I then appear in their session, rather than they visit a website and enter their details and wait for me. This is a common use-case, since the users' machine is a virtual desktop, and the session broker is connecting the user via RDP. They never have a session with their desktop unless it's a remote desktop session. At the moment, if I use either of the said products to get an unattended support session going, all I can see is the login screen of the physical console, telling me that a remote session is in progress. Are there alternative tools which will make me happy?

    Read the article

  • Intel video driver upgrade now makes my external monitor display red-only with HDMI cable.

    - by Eli
    I have an HP G60 notebook with a Mobile Intel 4 Series Express Chipset video display (Driver version is 8.15.10.2021). OS is Win7 Home Premium. I also have an LG widescreen display that I was connecting to the laptop using an HDMI cable. It was working great, until I applied an Intel 4 Series Express Chipset update from Windows Update. After the update, if I plug the laptop to the monitor using the HDMI cable, it appears I only get the Magenta channel, cause that is all I see. If I connect with the VGA cable, it works fine. So, is it possible it is just the HDMI cable (which IS cheap in this case - fire sale at Blockbuster), and not related to the video driver update at all?

    Read the article

  • Web-based (intranet / non-hosted) timesheet / project tracking tools

    - by warren
    I realize some similar questions have been asked along these lines before, but from reading-through them today, it appears they don't match my use case. I am looking for a web-based, non-hosted time and project tracking tool. I've downloaded Collabtive so far, but am looking for other suggestions, too. My list of requirements: runs on standard LAMP stack non-hosted (ie, there is an option to download and run it on a local server) not a desktop/single-user application easy-to-use - my audience is a mix of technical and non-technical folks easy to maintain - when time for upgrading comes, I'd really like to not have to rebuild the app (a la ./configure ; make ; make install) needs to support multiple users free-form project additions: we don't have a central project management authority (users should be able to add whatever they're working on, not merely from a drop-down) Does anyone here have experience with such tools? It doesn't have to be free.. but free is always nice :)

    Read the article

  • DDD and Value Objects. Are mutable Value Objects a good candidate for Non Aggr. Root Entity?

    - by Tony
    Here is a little problem Have an entity, with a value object. Not a problem. I replace a value object for a new one, then nhibernate inserts the new value and orphan the old one, then deletes it. Ok, that's a problem. Insured is my entity in my domain. He has a collection of Addresses (value objects). One of the addresses is the MailingAddress. When we want to update the mailing address, let's say zipcode was wrong, following Mr. Evans doctrine, we must replace the old object for a new one since it's immutable (a value object right?). But we don't want to delete the row thou, because that address's PK is a FK in a MailingHistory table. So, following Mr. Evans doctrine, we are pretty much screwed here. Unless i make my addressses Entities, so i don't have to "replace" it, and simply update its zipcode member, like the old good days. What would you suggest me in this case? The way i see it, ValueObjects are only useful when you want to encapsulate a group of database table's columns (component in nhibernate). Everything that has a persistence id in the database, is better off to make it an Entity (not necessarily an aggregate root) so you can update its members without recreating the whole object graph, specially if that's a deep-nested object. Do you concur? Is it allowed by Mr. Evans to have a mutable value object? Or is a mutable value object a candidate for an Entity? Thanks

    Read the article

  • Cron: job starts but doesn't complete

    - by Guandalino
    I have a problem with a cron job which starts but doesn't complete. Running the command manually works fine. I already read the page about cron issues and solutions here on AskUbuntu, tried the proposed solutions but didn't find an answer working in my case. I'm using Ubuntu 12.04. $ crontab -e SHELL=/bin/bash # otherwise it would be /bin/sh 59 16 * * * /bin/duply calendar backup > /tmp/duply.log Btw, the cron file ends with an empty line, as someone pointed out. Once the job has "finished"...: $ cat /tmp/duply.log Start duply v1.5.7, time is 2012-06-22 16:59:01. Instead, running manually the script it works correctly and gives this output: Start duply v1.5.7, time is 2012-06-22 17:06:39. [cut] ... here is a long output generated by duply. ... and yes, files have been backed up. [cut] --- Finished state OK at 17:06:42.581 - Runtime 00:00:03.170 --- I also tried to restart the cron daemon (sudo service cron restart) but nothing changed. Do you have any suggestion to fix the issue?

    Read the article

  • How do I convert this filetype to pdf?

    - by Gnoupi
    This question is coming back often, and the general answers are very often the same. In an objective to concentrate useful information in one place, here is a community wiki about it. How can I convert this filetype to pdf? This question will have two kind of answers: The generic case, which works for most filetypes. The specific cases, which should be one answer per filetype. Restricting the OS field to Windows, as most of these questions are about this OS. This may change eventually. As it is community wiki, feel free to edit this question to improve it as well.

    Read the article

  • How to consolidate servers with the not-very-strong infrastructure

    - by Sim
    All, Situation We are in retail industry with about 10 distributors and use Solomon as the standard ERP for all our systems Each distributor has 1 HQ and 5 - 10 branches, each branch has their own server (Windows 2000/XP/2003 + Solomon + another built-in POS system) Everyday, branches has to extract data and send (via email/Skype) to HQ for data consolidation purpose When we first deployed our ERP, the infrastructure (e.g. Internet connection) wasn't reliable enough. That's why we went with the de-centralized model (each branch got their own server) Now, the infrastructure is mature already. And we need to consolidate data more quickly (not from branches -- HQ -- our company but something like HQ -- our company only) Goal We just have Solomon servers in distributor HQ. All the transactions in branches (retrieved from POS) will by synchronized with HQ server directly) There is a backup plan just in case the Internet goes down, or HQ server goes down Question With the above question, could you guys suggests some model for me ? Should we use Terminal services, any other solutions ? Any watchout/suggestions ? Any good article to read 'bout this ? Thanks a lot

    Read the article

  • How to choose size for a cloud server (rackspace)

    - by Emil
    We're going to test the rackspace cloud next week to see how it's working with our web app. It's a LAMP environment with a lot of MySQL databases. How do I choose the "right" server size? On Rackspace I can choose slices with the memory of 256, 512, 1024, 2048, 4096 etc. Right now we don't have a lot of traffic (approx. 1000 visitors/day) but I thought the whole "cloud" idea was to not be limited and auto scale. Update: What I'm looking for is now a specification of what I need. I know it's too complex. I'm looking for examples, case studies etc. It would be interesting to hear something like "Yes we're serving 10 000 daily requests without spikes on a LAMP stack with only one slice on with 2 GB RAM".

    Read the article

  • MVC Validation with ModelState.isValid through a wizard

    - by Emmanuel TOPE
    I'm working on a small educational project on MVC 3, and I'm facing a small problem, when attempting to handle validation in my application through a wizard. I tried to get benefit from the ability of MVC3 to deliver content of a different view using the same URL, when handling an [HttpPost] method on a page. I my case,my main model's class contains about ten [Required] properties, that I would like to expose through a small wizard in 3 steps , So I want that the user may be able to enter his personal informations in the first step, then respond to some questions in the second stepp and finally receive a confirmation mail from the web application whit his credentials in the last step. I can't access the last step, because of the ModelState.isValid method that I use to handle validations, and which can't perform properly if I define some properties as [Required], but don't put them on the first view. As the replies to those questions remain in a couple of choices, I've thinked that I may use some nullable bool? for in order to avoid validation issues, but know that it's not the proper way. Are there someone who would like to help me find a way to extend my validation to those three steps ? Thanks in advance and sorry for my english, I'm not a native speaker.

    Read the article

  • Share on: FB, Tweet, Digg, Linkedin, Delicious, My mother, ... it's just on fashion, or some real value?

    - by Marco Demaio
    Nowadays your site is not in fashion if you don't show at least a couple of share buttons like these: Is this just fashion, or do people actually get something good out of it? When I say "something good" I mostly mean something that you could measure, and not just the feeling that was good. Maybe I can better explain with an example: did you notice (in some way) that many people clicked on those links to share your page/s on those web 2.0 social sites? And in such a case on which social networks did you see they mostly share your pages? BTW I'm not talking about Google PR, i know all web 2.0 social sites use nofollow everywhere and even hidden links, so they are useless by themselves for PR. UPDATE: According to this video, Google's Alter Ego says that they now use in some way data from social sites in ranking. If this is true, it's obvious that the Share on button for FB, Tweet, etc are definitely of some values. But again my question is more about what you noticed in your real experience to be a direct benefit of adding those type of "Share On" links on your webisite? I.e. did you see more traffic coming in form FB, or some users who bought your products because of FB or Twitter? Or any other benefits? Thanks

    Read the article

  • Testcase runner for parametrized testcases

    - by Razer
    Let me explain my situation. I'm planning a kind of test case runner for doing testcases on external devices, which are microcontroller based. Lets consider the devices: Device 1 Device 2 There exist a lot of test cases which can be run with one of the devices above. For example: Testcase 1 Testcase 2 The main reason that all the testcases can be run with any device is, that the testcases validates some standard and this software should be extensible for future devices. The testcases itself must be runnable with changing parameters. For example Testcase 1 does some Timing Verification the testcase needs as input parameter the datarate: 4800, 9600, 19200. Now hoping you understand the situation, let me explain my design questions. For implementing the test cases I thought about an Attribute based approach, like nunit does it. The more complicated problem is, how to define the parametrized testcases? Like this: Device 1: Testcase 1: datarate: 4800, 9600, 19200 Testcase 2: supply: 1, 2, 3 Device 2: Testcase 1: datarate: 9600, 19200, 38400 Testcase 2: supply: 3, 4, 5 How would you design such a framework? I've done a similar desin in python where I had for every device a XML containing the testcase definitions like: <Testcase="Testcase 1" datarate=4800/> <Testcase="Testcase 1" datarate=9600/> <Testcase="Testcase 1" datarate=19200/>

    Read the article

  • juicy couture sale would nanytime go for any added casting

    - by user109129
    Depaccident aloft the achievement and the air-conditionedior of getting, you can admissionment the acclimateed acadding ambiencel as per your acquiesceadeptness.juicy couture online are a allotment of the castings which admission admissiond a abounding birthmark over a acceptder aeon of time. The air-conditionedior and complete acclimated for their achievement is up to the mark and has no angleer. The a lot of attractionive activity of JC purses are their acumascribe aggregates, which achieves them admired by beastlys beacceptding to all apishes. These are simple to be admissionmentd from onbandage retail aliment. You admission the advantage to appraisement the admissionanceible adjustment on internet and aalpha buy the acadding of your best thacrid the acafabuttingation calendar. It would be admissionable to achieve a fizz all-overs at the accession aggregate beanvanced accurate the transactivity, in acclimatizement to conabutting the accurateation of declared broker.Alacquireing, tachievement are so aapprenticeding advantages in the exchange that it has in fact beappear difficult to achieve the acclimateed best, but if you alattainable admissionment juicy couture sale, you would nanytime go for any added casting. Their beside attaccident with adjustment of blooms is the best activitys which a exhausted woman may annual for. The bandage of these tots is in fact able, and they do not aperture out even afterwardss acrid and added acquireing.acclimateed admeaconstantments of Juicy couture battleaccoutrements achieve them applicative to accouterment arbitrary admeaconstantment requirements. Some woman like huge accoutrements while addeds like acclimatized admeaconstantmentd tots. In any case, the cobasicotmentments of these purses are bottomless and admission the acclimateation to acclimatize sanytimeal sbasic activitys. The admirable and dejected bloom abuttals is anadded complete aspect of JC getting. acquire the acclimateed ones for you accordanceing to the accumulating of your accoutermentss, and leave a ambrosial afterwardseffect on addeds. abonfire and acclimateed contrasts are in trend nowacanicule, so accrue yourself up to date by purchasing this air-conditionedb accumulating from Juicy Couture.

    Read the article

  • if/else statements or exceptions

    - by Thaven
    I don't know, that this question fit better on this board, or stackoverflow, but because my question is connected rather to practices, that some specified problem. So, consider an object that does something. And this something can (but should not!) can go wrong. So, this situation can be resolved in two way: first, with exceptions: DoSomethingClass exampleObject = new DoSomethingClass(); try { exampleObject.DoSomething(); } catch (ThisCanGoWrongException ex) { [...] } And second, with if statement: DoSomethingClass exampleObject = new DoSomethingClass(); if(!exampleObject.DoSomething()) { [...] } Second case in more sophisticated way: DoSomethingClass exampleObject = new DoSomethingClass(); ErrorHandler error = exampleObject.DoSomething(); if (error.HasError) { if(error.ErrorType == ErrorType.DivideByPotato) { [...] } } which way is better? In one hand, I heard that exception should be used only for real unexpected situations, and if programist know, that something may happen, he should used if/else. In second hand, Robert C. Martin in his book Clean Code Wrote, that exception are far more object oriented, and more simple to keep clean.

    Read the article

  • Automatic LaTex document generation from Excel spreadsheet

    - by Bowler
    I have some data in an excel file from which I have to generate a report. I repeat this task fairly regularly and am looking to automate it. I have a LaTeX project into which I usually just copy data by hand, export the necessary worksheets as pdfs and add them to my LaTeX project and compile with pdflatex. It has occured to me that there must be a way to automate this process. Is there an efficient way to export the data from excel and into a LaTeX project, possibly a vba script in excel could run the process? Also, it doesn't have to be LaTeX, I'm not all that experienced with MS office's more advanced features is there some way akin to a mail merge that I could achieve this with? In some ways this might be better in case I have to pass the work on to someone who doesn't know LaTeX. Thanks.

    Read the article

  • OS X will not register newly installed network adapters

    - by Chris
    I have purchased an Edimax 7318USg and tested it on a Windows machine (works). The installation process for the software for this adapter runs smoothly. However, OS X simply does not recognize new network adapters. When you go to System Preferences/Network, a new network adapter should be present/there should be an alert. This is not the case. Why might this be? Is there a setting I may reset to force the operating system to recognize this? Thanks!

    Read the article

  • Which approach would lead to an API that is easier to use?

    - by Clem
    I'm writing a JavaScript API and for a particular case, I'm wondering which approach is the sexiest. Let's take an example: writing a VideoPlayer, I add a getCurrentTime method which gives the elapsed time since the start. The first approach simply declares getCurrentTime as follows: getCurrentTime():number where number is the native number type. This approach includes a CURRENT_TIME_CHANGED event so that API users can add callbacks to be aware of time changes. Listening to this event would look like the following: myVideoPlayer.addEventListener(CURRENT_TIME_CHANGED, function(evt){ console.log ("current time = "+evt.getDispatcher().getCurrentTime()); }); The second approach declares getCurrentTime differently: getCurrentTime():CustomNumber where CustomNumber is a custom number object, not the native one. This custom object dispatches a VALUE_CHANGED event when its value changes, so there is no need for the CURRENT_TIME_CHANGED event! Just listen to the returned object for value changes! Listening to this event would look like the following: myVideoPlayer.getCurrentTime().addEventListener(VALUE_CHANGED, function(evt){ console.log ("current time = "+evt.getDispatcher().valueOf()); }); Note that CustomNumber has a valueOf method which returns a native number that lets the returned CustomNumber object being used as a number, so: var result = myVideoPlayer.getCurrentTime()+5; will work! So in the first approach, we listen to an object for a change in its property's value. In the second one we directly listen to the property for a change on its value. There are multiple pros and cons for each approach, I just want to know which one the developers would prefer to use!

    Read the article

  • Wifi not working on Acer Aspire One D270

    - by Dani
    brand new baby linux user here, never used Ubuntu or any other linux OS before, so be gentle and use short words! I installed Ubuntu 12.04 on my new Acer Aspire One D270-F61C/KF netbook (it's a Japanese computer which had Japanese windows preinstalled, and I decided to take the plunge and try Ubuntu because English Windows costs the earth and stars). Wifi isn't working; I enter my wireless password, it tries to connect for a while, then asks for my password again. And KEEPS ASKING, every few minutes. Wired connection works fine. Wireless card is a Broadcom BCM4313; I have the "additional drivers" checked and installed (I tried unchecking and then reinstalling them in case that would help, no joy, and now my home wifi connection isn't showing up in the list of available connections, argh). I've done a lot of googling and I gather there's a lot of issues with Broadcom cards, but some of the answers are for earlier ubuntu builds and many of them are a bit confusing for a new user. I gather I need to try installing some new drivers other than the proprietary ones provided, but I'm having trouble figuring out how that's done. Anyone got some simple, step by step instructions for me? Please bear in mind, TOTAL N00B. (EDIT): OKAY, got it fixed finally; after suggestions on the Ubuntu forums and messing around with drivers, what finally worked was installing Wicd. Not... using Wicd, for some reason, just installing it fixed it. ...I CHOOSE NOT TO QUESTION IT.

    Read the article

  • How to keep your third party libraries up to date?

    - by Joonas Pulakka
    Let's say that I have a project that depends on 10 libraries, and within my project's trunk I'm free to use any versions of those libraries. So I start with the most recent versions. Then, each of those libraries gets an update once a month (on average). Now, keeping my trunk completely up to date would require updating a library reference every three days. This is obviously too much. Even though usually version 1.2.3 is a drop-in replacement for version 1.2.2, you never know without testing. Unit tests aren't enough; if it's a DB / file engine, you have to ensure that it works properly with files that were created with older versions, and maybe vice versa. If it has something to do with GUI, you have to visually inspect everything. And so on. How do you handle this? Some possible approaches: If it ain't broke, don't fix it. Stay with your current version of the library as long as you don't notice anything wrong with it when used in your application, no matter how often the library vendor publishes updates. Small incremental changes are just waste. Update frequently in order to keep change small. Since you'll have to update some day in any case, it's better to update often so that you notice any problems early when they're easy to fix, instead of jumping over several versions and letting potential problems to accumulate. Something in between. Is there a sweet spot?

    Read the article

  • Customizing the NUnit GUI for data-driven testing

    - by rwong
    My test project consists of a set of input data files which is fed into a piece of legacy third-party software. Since the input data files for this software are difficult to construct (not something that can be done intentionally), I am not going to add new input data files. Each input data file will be subject to a set of "test functions". Some of the test functions can be invoked independently. Other test functions represent the stages of a sequential operation - if an earlier stage fails, the subsequent stages do not need to be executed. I have experimented with the NUnit parametrized test case (TestCaseAttribute and TestCaseSourceAttribute), passing in the list of data files as test cases. I am generally satisfied with the the ability to select the input data for testing. However, I would like to see if it is possible to customize its GUI's tree structure, so that the "test functions" become the children of the "input data". For example: File #1 CheckFileTypeTest GetFileTopLevelStructureTest CompleteProcessTest StageOneTest StageTwoTest StageThreeTest File #2 CheckFileTypeTest GetFileTopLevelStructureTest CompleteProcessTest StageOneTest StageTwoTest StageThreeTest This will be useful for identifying the stage that failed during the processing of a particular input file. Is there any tips and tricks that will enable the new tree layout? Do I need to customize NUnit to get this layout?

    Read the article

  • Solving Big Problems with Oracle R Enterprise, Part I

    - by dbayard
    Abstract: This blog post will show how we used Oracle R Enterprise to tackle a customer’s big calculation problem across a big data set. Overview: Databases are great for managing large amounts of data in a central place with rigorous enterprise-level controls.  R is great for doing advanced computations.  Sometimes you need to do advanced computations on large amounts of data, subject to rigorous enterprise-level concerns.  This blog post shows how Oracle R Enterprise enables R plus the Oracle Database enabled us to do some pretty sophisticated calculations across 1 million accounts (each with many detailed records) in minutes. The problem: A financial services customer of mine has a need to calculate the historical internal rate of return (IRR) for its customers’ portfolios.  This information is needed for customer statements and the online web application.  In the past, they had solved this with a home-grown application that pulled trade and account data out of their data warehouse and ran the calculations.  But this home-grown application was not able to do this fast enough, plus it was a challenge for them to write and maintain the code that did the IRR calculation. IRR – a problem that R is good at solving: Internal Rate of Return is an interesting calculation in that in most real-world scenarios it is impractical to calculate exactly.  Rather, IRR is a calculation where approximation techniques need to be used.  In this blog post, we will discuss calculating the “money weighted rate of return” but in the actual customer proof of concept we used R to calculate both money weighted rate of returns and time weighted rate of returns.  You can learn more about the money weighted rate of returns here: http://www.wikinvest.com/wiki/Money-weighted_return First Steps- Calculating IRR in R We will start with calculating the IRR in standalone/desktop R.  In our second post, we will show how to take this desktop R function, deploy it to an Oracle Database, and make it work at real-world scale.  The first step we did was to get some sample data.  For a historical IRR calculation, you have a balances and cash flows.  In our case, the customer provided us with several accounts worth of sample data in Microsoft Excel.      The above figure shows part of the spreadsheet of sample data.  The data provides balances and cash flows for a sample account (BMV=beginning market value. FLOW=cash flow in/out of account. EMV=ending market value). Once we had the sample spreadsheet, the next step we did was to read the Excel data into R.  This is something that R does well.  R offers multiple ways to work with spreadsheet data.  For instance, one could save the spreadsheet as a .csv file.  In our case, the customer provided a spreadsheet file containing multiple sheets where each sheet provided data for a different sample account.  To handle this easily, we took advantage of the RODBC package which allowed us to read the Excel data sheet-by-sheet without having to create individual .csv files.  We wrote ourselves a little helper function called getsheet() around the RODBC package.  Then we loaded all of the sample accounts into a data.frame called SimpleMWRRData. Writing the IRR function At this point, it was time to write the money weighted rate of return (MWRR) function itself.  The definition of MWRR is easily found on the internet or if you are old school you can look in an investment performance text book.  In the customer proof, we based our calculations off the ones defined in the The Handbook of Investment Performance: A User’s Guide by David Spaulding since this is the reference book used by the customer.  (One of the nice things we found during the course of this proof-of-concept is that by using R to write our IRR functions we could easily incorporate the specific variations and business rules of the customer into the calculation.) The key thing with calculating IRR is the need to solve a complex equation with a numerical approximation technique.  For IRR, you need to find the value of the rate of return (r) that sets the Net Present Value of all the flows in and out of the account to zero.  With R, we solve this by defining our NPV function: where bmv is the beginning market value, cf is a vector of cash flows, t is a vector of time (relative to the beginning), emv is the ending market value, and tend is the ending time. Since solving for r is a one-dimensional optimization problem, we decided to take advantage of R’s optimize method (http://stat.ethz.ch/R-manual/R-patched/library/stats/html/optimize.html). The optimize method can be used to find a minimum or maximum; to find the value of r where our npv function is closest to zero, we wrapped our npv function inside the abs function and asked optimize to find the minimum.  Here is an example of using optimize: where low and high are scalars that indicate the range to search for an answer.   To test this out, we need to set values for bmv, cf, t, emv, tend, low, and high.  We will set low and high to some reasonable defaults. For example, this account had a negative 2.2% money weighted rate of return. Enhancing and Packaging the IRR function With numerical approximation methods like optimize, sometimes you will not be able to find an answer with your initial set of inputs.  To account for this, our approach was to first try to find an answer for r within a narrow range, then if we did not find an answer, try calling optimize() again with a broader range.  See the R help page on optimize()  for more details about the search range and its algorithm. At this point, we can now write a simplified version of our MWRR function.  (Our real-world version is  more sophisticated in that it calculates rate of returns for 5 different time periods [since inception, last quarter, year-to-date, last year, year before last year] in a single invocation.  In our actual customer proof, we also defined time-weighted rate of return calculations.  The beauty of R is that it was very easy to add these enhancements and additional calculations to our IRR package.)To simplify code deployment, we then created a new package of our IRR functions and sample data.  For this blog post, we only need to include our SimpleMWRR function and our SimpleMWRRData sample data.  We created the shell of the package by calling: To turn this package skeleton into something usable, at a minimum you need to edit the SimpleMWRR.Rd and SimpleMWRRData.Rd files in the \man subdirectory.  In those files, you need to at least provide a value for the “title” section. Once that is done, you can change directory to the IRR directory and type at the command-line: The myIRR package for this blog post (which has both SimpleMWRR source and SimpleMWRRData sample data) is downloadable from here: myIRR package Testing the myIRR package Here is an example of testing our IRR function once it was converted to an installable package: Calculating IRR for All the Accounts So far, we have shown how to calculate IRR for a single account.  The real-world issue is how do you calculate IRR for all of the accounts?This is the kind of situation where we can leverage the “Split-Apply-Combine” approach (see http://www.cscs.umich.edu/~crshalizi/weblog/815.html).  Given that our sample data can fit in memory, one easy approach is to use R’s “by” function.  (Other approaches to Split-Apply-Combine such as plyr can also be used.  See http://4dpiecharts.com/2011/12/16/a-quick-primer-on-split-apply-combine-problems/). Here is an example showing the use of “by” to calculate the money weighted rate of return for each account in our sample data set.  Recap and Next Steps At this point, you’ve seen the power of R being used to calculate IRR.  There were several good things: R could easily work with the spreadsheets of sample data we were given R’s optimize() function provided a nice way to solve for IRR- it was both fast and allowed us to avoid having to code our own iterative approximation algorithm R was a convenient language to express the customer-specific variations, business-rules, and exceptions that often occur in real-world calculations- these could be easily added to our IRR functions The Split-Apply-Combine technique can be used to perform calculations of IRR for multiple accounts at once. However, there are several challenges yet to be conquered at this point in our story: The actual data that needs to be used lives in a database, not in a spreadsheet The actual data is much, much bigger- too big to fit into the normal R memory space and too big to want to move across the network The overall process needs to run fast- much faster than a single processor The actual data needs to be kept secured- another reason to not want to move it from the database and across the network And the process of calculating the IRR needs to be integrated together with other database ETL activities, so that IRR’s can be calculated as part of the data warehouse refresh processes In our next blog post in this series, we will show you how Oracle R Enterprise solved these challenges.

    Read the article

  • Graduate expectations versus reality

    - by Bobby Tables
    When choosing what we want to study, and do with our careers and lives, we all have some expectations of what it is going to be like. Now that I've been in the industry for almost a decade, I've been reflecting a bit on what I thought (back when I was studying Computer Science) programming working life was going to be like, and how it's actually turning out to be. My two biggest shocks (or should I say, broken expectations) by far are the sheer amount of maintenance work involved in software, and the overall lack of professionalism: Maintenance: At uni, we were all told that the majority of software work is maintenance of existing systems. So I knew to expect this in the abstract. But I never imagined exactly how overwhelming this would turn out to be. Perhaps it's something I mentally glazed over, and hoped I'd be building cool new stuff from scratch a lot more. But it really is the case that most jobs are overwhelmingly maintenance, bug fixing, and support oriented. Lack of professionalism: At uni, I always had the impression that commercial software work is very process-oriented and stringently engineered. I had images of ISO processes, reams of technical documentation, every feature and bug being strictly documented, and a generally professional environment. It came as a huge shock to realise that most software companies operate no differently to a team of students working on a large semester-long project. And I've worked in both the small agile hack shop, and the medium sized corporate enterprise. While I wouldn't say that it's always been outright "unprofessional", it definitely feels like the software industry (on the whole) is far from the strong engineering discipline that I expected it to be. Has anyone else had similar experiences to this? What are the ways in which your expectations of what our profession would be like were different to the reality?

    Read the article

  • Fault tolerance with a pair of tightly coupled services

    - by cogitor
    I have two tightly coupled services that can run on completely different nodes (e.g. ServiceA and ServiceB). If I start up another replicated copy of both these services for backup purposes (ServiceA-2 and ServiceB-2), what would be the best way of setting up a fault tolerant distributed system such that on a fault in any of the tightly coupled services ServiceA or ServiceB the whole communication should go through backup ServiceA-2 and ServiceB-2? Overall, all the communication should go either through both services or their backup replicas. |---- Service A | | Service B | | (backup branch - used only on fault in Service A or B) ---- Service A-2 | Service B-2 Note that in case that Service A goes down, data from Service B would be incorrect (and vice versa). Load balancing between the primary and backup branch is also not feasible.

    Read the article

  • Backup media manager, library or similar reference application

    - by Tarnschaf
    I'm looking for a backup media manager that will keep me up-to-date on where my backups are, how they're stored and what's stored on them. I want it to be able to do and keep track of the following: my used backup media (e.g. DVD1, DVD2) my backed-up assets in high-level (such as "family-photos from 2003", "laptop drivers") details of the assets ("Ninas Birthday 2003") where the backup media is currently stored when the media has been burned (to re-burn in case of media degeneration). It should be possible to navigate back and forth between media and assets. I also thought about marking assets as "deprecated". If all assets on a media are deprecated, the program should tell me so I don't have to keep it any more. Does anyone know of a program with this feature-set? Or will I have to start my own reference in something like Access?

    Read the article

  • How to "translate" interdependent object states in code?

    - by Earl Grey
    I have the following problem. My UI interace contains several buttons, labels, and other visual information. I am able to describe every possible workflow scenario that should be be allowed on that UI. That means I can describe it like this - when button A is pressed, the following should follow - In the case of that A button, there are three independent factors that influence the possible result when pushing the A button. The state of the session (blank, single, multi, multi special), the actual work that is being done by the system at the moment of pressing the A button (nothing was happening, work was being done, work was paused) and a separate UI element that has two states (on , off)..This gives me a 3 dimensional cube with 24 possible outcomes. I could write code for this using if cycles, switch cycles etc....but the problem is, I have another 7 buttons on that ui, I can enter this UI from different states..some buttons change the state, some change parameters... To sum up, the combinations are mindbogling and I am not able come up with a methodology that scales and is systematically reliable. I am able to describe EVERY workflow with words, I am sure my description is complete and without logical errors. But I am not able to translate that into code. I was trying to draw flowcharts but it soon became visually too complicated due to too many if "emafors". Can you advice how to proceeed?

    Read the article

  • Why Are Minimized Programs Often Slow to Open Again?

    - by Jason Fitzpatrick
    It seems particularly counterintuitive: you minimize an application because you plan on returning to it later and wish to skip shutting the application down and restarting it later, but sometimes maximizing it takes even longer than launching it fresh. What gives? Today’s Question & Answer session comes to us courtesy of SuperUser—a subdivision of Stack Exchange, a community-driven grouping of Q&A web sites. The Question SuperUser reader Bart wants to know why he’s not saving any time with application minimization: I’m working in Photoshop CS6 and multiple browsers a lot. I’m not using them all at once, so sometimes some applications are minimized to taskbar for hours or days. The problem is, when I try to maximize them from the taskbar – it sometimes takes longer than starting them! Especially Photoshop feels really weird for many seconds after finally showing up, it’s slow, unresponsive and even sometimes totally freezes for minute or two. It’s not a hardware problem as it’s been like that since always on all on my PCs. Would I also notice it after upgrading my HDD to SDD and adding RAM (my main PC holds 4 GB currently)? Could guys with powerful pcs / macs tell me – does it also happen to you? I guess OSes somehow “focus” on active software and move all the resources away from the ones that run, but are not used. Is it possible to somehow set RAM / CPU / HDD priorities or something, for let’s say, Photoshop, so it won’t slow down after long period of inactivity? So what is the deal? Why does he find himself waiting to maximize a minimized app? The Answer SuperUser contributor Allquixotic explains why: Summary The immediate problem is that the programs that you have minimized are being paged out to the “page file” on your hard disk. This symptom can be improved by installing a Solid State Disk (SSD), adding more RAM to your system, reducing the number of programs you have open, or upgrading to a newer system architecture (for instance, Ivy Bridge or Haswell). Out of these options, adding more RAM is generally the most effective solution. Explanation The default behavior of Windows is to give active applications priority over inactive applications for having a spot in RAM. When there’s significant memory pressure (meaning the system doesn’t have a lot of free RAM if it were to let every program have all the RAM it wants), it starts putting minimized programs into the page file, which means it writes out their contents from RAM to disk, and then makes that area of RAM free. That free RAM helps programs you’re actively using — say, your web browser — run faster, because if they need to claim a new segment of RAM (like when you open a new tab), they can do so. This “free” RAM is also used as page cache, which means that when active programs attempt to read data on your hard disk, that data might be cached in RAM, which prevents your hard disk from being accessed to get that data. By using the majority of your RAM for page cache, and swapping out unused programs to disk, Windows is trying to improve responsiveness of the program(s) you are actively using, by making RAM available to them, and caching the files they access in RAM instead of the hard disk. The downside of this behavior is that minimized programs can take a while to have their contents copied from the page file, on disk, back into RAM. The time increases the larger the program’s footprint in memory. This is why you experience that delay when maximizing Photoshop. RAM is many times faster than a hard disk (depending on the specific hardware, it can be up to several orders of magnitude). An SSD is considerably faster than a hard disk, but it is still slower than RAM by orders of magnitude. Having your page file on an SSD will help, but it will also wear out the SSD more quickly than usual if your page file is heavily utilized due to RAM pressure. Remedies Here is an explanation of the available remedies, and their general effectiveness: Installing more RAM: This is the recommended path. If your system does not support more RAM than you already have installed, you will need to upgrade more of your system: possibly your motherboard, CPU, chassis, power supply, etc. depending on how old it is. If it’s a laptop, chances are you’ll have to buy an entire new laptop that supports more installed RAM. When you install more RAM, you reduce memory pressure, which reduces use of the page file, which is a good thing all around. You also make available more RAM for page cache, which will make all programs that access the hard disk run faster. As of Q4 2013, my personal recommendation is that you have at least 8 GB of RAM for a desktop or laptop whose purpose is anything more complex than web browsing and email. That means photo editing, video editing/viewing, playing computer games, audio editing or recording, programming / development, etc. all should have at least 8 GB of RAM, if not more. Run fewer programs at a time: This will only work if the programs you are running do not use a lot of memory on their own. Unfortunately, Adobe Creative Suite products such as Photoshop CS6 are known for using an enormous amount of memory. This also limits your multitasking ability. It’s a temporary, free remedy, but it can be an inconvenience to close down your web browser or Word every time you start Photoshop, for instance. This also wouldn’t stop Photoshop from being swapped when minimizing it, so it really isn’t a very effective solution. It only helps in some specific situations. Install an SSD: If your page file is on an SSD, the SSD’s improved speed compared to a hard disk will result in generally improved performance when the page file has to be read from or written to. Be aware that SSDs are not designed to withstand a very frequent and constant random stream of writes; they can only be written over a limited number of times before they start to break down. Heavy use of a page file is not a particularly good workload for an SSD. You should install an SSD in combination with a large amount of RAM if you want maximum performance while preserving the longevity of the SSD. Use a newer system architecture: Depending on the age of your system, you may be using an out of date system architecture. The “system architecture” is generally defined as the “generation” (think generations like children, parents, grandparents, etc.) of the motherboard and CPU. Newer generations generally support faster I/O (input/output), better memory bandwidth, lower latency, and less contention over shared resources, instead providing dedicated links between components. For example, starting with the “Nehalem” generation (around 2009), the Front-Side Bus (FSB) was eliminated, which removed a common bottleneck, because almost all system components had to share the same FSB for transmitting data. This was replaced with a “point to point” architecture, meaning that each component gets its own dedicated “lane” to the CPU, which continues to be improved every few years with new generations. You will generally see a more significant improvement in overall system performance depending on the “gap” between your computer’s architecture and the latest one available. For example, a Pentium 4 architecture from 2004 is going to see a much more significant improvement upgrading to “Haswell” (the latest as of Q4 2013) than a “Sandy Bridge” architecture from ~2010. Links Related questions: How to reduce disk thrashing (paging)? Windows Swap (Page File): Enable or Disable? Also, just in case you’re considering it, you really shouldn’t disable the page file, as this will only make matters worse; see here. And, in case you needed extra convincing to leave the Windows Page File alone, see here and here. Have something to add to the explanation? Sound off in the the comments. Want to read more answers from other tech-savvy Stack Exchange users? Check out the full discussion thread here.     

    Read the article

< Previous Page | 391 392 393 394 395 396 397 398 399 400 401 402  | Next Page >