Search Results

Search found 3195 results on 128 pages for 'tip and tricks'.

Page 117/128 | < Previous Page | 113 114 115 116 117 118 119 120 121 122 123 124  | Next Page >

• Activate a python virtual environment using activate_this.py in a fabfile on Windows

  - by Rudy Lattae

  I have a Fabric task that needs to access the settings of my Django project. On Windows, I'm unable to install Fabric into the project's virtualenv (issues with Paramiko + pycrypto deps). However, I am able to install Fabric in my system-wide site-packages, no problem. I have installed Django into the project's virtualenv and I am able to use all the " python manage.py" commands easily when I activate the virtualenv with the "VIRTUALENV\Scripts\activate.bat" script. I have a fabric tasks file (fabfile.py) in my project that provides tasks for setup, test, deploy, etc. Some of the tasks in my fabfile need to access the settings of my django project through "from django.conf import settings". Since the only usable Fabric install I have is in my system-wide site-packages, I need to activate the virtualenv within my fabfile so django becomes available. To do this, I use the "activate_this" module of the project's virtualenv in order to have access to the project settings and such. Using "print sys.path" before and after I execute activate_this.py, I can tell the python path changes to point to the virtualenv for the project. However, I still cannot import django.conf.settings. I have been able to successfully do this on *nix (Ubuntu and CentOS) and in Cygwin. Do you use this setup/workflow on Windows? If so Can you help me figure out why this wont work on Windows or provide any tips and tricks to get around this issue? Thanks and Cheers. REF: http://virtualenv.openplans.org/#id9 | Using Virtualenv without bin/python Local development environment: Python 2.5.4 Virtualenv 1.4.6 Fabric 0.9.0 Pip 0.6.1 Django 1.1.1 Windows XP (SP3)

  Read the article

• Newbie question: How do you layout an icon, 2 text lines and a button?

  - by Keith Barrows

  I am trying to extend a sample I found at http://developer.android.com/resources/articles/layout-tricks-efficiency.html. I am a brand new MonoDroid developer, just installed it yesterday, and trying to jump right into UI design and so far it is not clicking for me completely. I have this main.xml: <?xml version="1.0" encoding="utf-8"?> <RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android" android:layout_width="fill_parent" android:layout_height="?android:attr/listPreferredItemHeight" android:padding="6dip"> <ImageView android:id="@+id/icon" android:layout_width="wrap_content" android:layout_height="fill_parent" android:layout_alignParentTop="true" android:layout_alignParentBottom="true" android:layout_marginRight="6dip" android:src="@drawable/icon" /> <TextView android:id="@+id/secondLine" android:layout_width="200dip" android:layout_height="26dip" android:layout_toRightOf="@id/icon" android:layout_alignParentBottom="true" android:layout_alignParentRight="true" android:singleLine="true" android:ellipsize="marquee" android:text="Second line which is a long line of text and needs to scroll" /> <TextView android:id="@+id/firstLine" android:layout_width="200dip" android:layout_height="wrap_content" android:layout_toRightOf="@id/icon" android:layout_alignParentRight="true" android:layout_alignParentTop="true" android:layout_above="@id/secondLine" android:layout_alignWithParentIfMissing="true" android:singleLine="true" android:ellipsize="marquee" android:gravity="center_vertical" android:text="First line" /> <Button android:id="@+id/logonButton" android:layout_width="50dip" android:layout_height="wrap_content" android:layout_toRightOf="@id/secondLine" android:layout_alignParentRight="true" android:layout_alignParentTop="true" android:gravity="center_vertical" android:text="Login" /> /> </RelativeLayout> What I am trying to do is have an icon on the left, 2 lines of text stacked in the middle and a button on the right. When I run this in my emulator I am seeing: The second line is not scrolling. The button does not show up. Is there by any chance a simple WYSIWYG editor for layout? Or is there an app to give me a quick view of my layout XML? Something like FireBug in FireFox would be fine. Barring the slim chance there are UI helpers for Droid, what am I doing wrong? :)

  Read the article

• Re-using aggregate level formulas in SQL - any good tactics?

  - by Cade Roux

  Imagine this case, but with a lot more component buckets and a lot more intermediates and outputs. Many of the intermediates are calculated at the detail level, but a few things are calculated at the aggregate level: DECLARE @Profitability AS TABLE ( Cust INT NOT NULL ,Category VARCHAR(10) NOT NULL ,Income DECIMAL(10, 2) NOT NULL ,Expense DECIMAL(10, 2) NOT NULL ) ; INSERT INTO @Profitability VALUES ( 1, 'Software', 100, 50 ) ; INSERT INTO @Profitability VALUES ( 2, 'Software', 100, 20 ) ; INSERT INTO @Profitability VALUES ( 3, 'Software', 100, 60 ) ; INSERT INTO @Profitability VALUES ( 4, 'Software', 500, 400 ) ; INSERT INTO @Profitability VALUES ( 5, 'Hardware', 1000, 550 ) ; INSERT INTO @Profitability VALUES ( 6, 'Hardware', 1000, 250 ) ; INSERT INTO @Profitability VALUES ( 7, 'Hardware', 1000, 700 ) ; INSERT INTO @Profitability VALUES ( 8, 'Hardware', 5000, 4500 ) ; SELECT Cust ,Profit = SUM(Income - Expense) ,Margin = SUM(Income - Expense) / SUM(Income) FROM @Profitability GROUP BY Cust SELECT Category ,Profit = SUM(Income - Expense) ,Margin = SUM(Income - Expense) / SUM(Income) FROM @Profitability GROUP BY Category SELECT Profit = SUM(Income - Expense) ,Margin = SUM(Income - Expense) / SUM(Income) FROM @Profitability Notice how the same formulae have to be used at the different aggregation levels. This results in code duplication. I have thought of using UDFs (either scalar or table valued with an OUTER APPLY, since many of the final results may share intermediates which have to be calculated at the aggregate level), but in my experience the scalar and multi-statement table-valued UDFs perform very poorly. Also thought about using more dynamic SQL and applying the formulas by name, basically. Any other tricks, techniques or tactics to keeping these kinds of formulae which need to be applied at different levels in sync and/or organized?

  Read the article

• Bubble sort algorithm implementations (Haskell vs. C)

  - by kingping

  Hello. I have written 2 implementation of bubble sort algorithm in C and Haskell. Haskell implementation: module Main where main = do contents <- readFile "./data" print "Data loaded. Sorting.." let newcontents = bubblesort contents writeFile "./data_new_ghc" newcontents print "Sorting done" bubblesort list = sort list [] False rev = reverse -- separated. To see rev2 = reverse -- who calls the routine sort (x1:x2:xs) acc _ | x1 > x2 = sort (x1:xs) (x2:acc) True sort (x1:xs) acc flag = sort xs (x1:acc) flag sort [] acc True = sort (rev acc) [] False sort _ acc _ = rev2 acc I've compared these two implementations having run both on file with size of 20 KiB. C implementation took about a second, Haskell — about 1 min 10 sec. I have also profiled the Haskell application: Compile for profiling: C:\Temp ghc -prof -auto-all -O --make Main Profile: C:\Temp Main.exe +RTS -p and got these results. This is a pseudocode of the algorithm: procedure bubbleSort( A : list of sortable items ) defined as: do swapped := false for each i in 0 to length(A) - 2 inclusive do: if A[i] > A[i+1] then swap( A[i], A[i+1] ) swapped := true end if end for while swapped end procedure I wonder if it's possible to make Haskell implementation work faster without changing the algorithm (there's are actually a few tricks to make it work faster, but neither implementations have these optimizations)

  Read the article

• Create a HTML table from nested maps (and vectors)

  - by Kenny164

  I'm trying to create a table (a work schedule) I have coded previously using python, I think it would be a nice introduction to the Clojure language for me. I have very little experience in Clojure (or lisp in that matter) and I've done my rounds in google and a good bit of trial and error but can't seem to get my head around this style of coding. Here is my sample data (will be coming from an sqlite database in the future): (def smpl2 (ref {"Salaried" [{"John Doe" ["12:00-20:00" nil nil nil "11:00-19:00"]} {"Mary Jane" [nil "12:00-20:00" nil nil nil "11:00-19:00"]}] "Shift Manager" [{"Peter Simpson" ["12:00-20:00" nil nil nil "11:00-19:00"]} {"Joe Jones" [nil "12:00-20:00" nil nil nil "11:00-19:00"]}] "Other" [{"Super Man" ["07:00-16:00" "07:00-16:00" "07:00-16:00" "07:00-16:00" "07:00-16:00"]}]})) I was trying to step through this originally using for then moving onto doseq and finally domap (which seems more successful) and dumping the contents into a html table (my original python program outputed this from a sqlite database into an excel spreadsheet using COM). Here is my attempt (the create-table fn): (defn html-doc [title & body] (html (doctype "xhtml/transitional") [:html [:head [:title title]] [:body body]])) (defn create-table [] [:h1 "Schedule"] [:hr] [:table (:style "border: 0; width: 90%") [:th "Name"][:th "Mon"][:th "Tue"][:th "Wed"] [:th "Thur"][:th "Fri"][:th "Sat"][:th "Sun"] [:tr (domap [ct @smpl2] [:tr [:td (key ct)] (domap [cl (val ct)] (domap [c cl] [:tr [:td (key c)]]))]) ]]) (defroutes tstr (GET "/" ((html-doc "Sample" create-table))) (ANY "*" 404)) That outputs the table with the sections (salaried, manager, etc) and the names in the sections, I just feel like I'm abusing the domap by nesting it too many times as I'll probably need to add more domaps just to get the shift times in their proper columns and the code is getting a 'dirty' feel to it. I apologize in advance if I'm not including enough information, I don't normally ask for help on coding, also this is my 1st SO question :). If you know any better approaches to do this or even tips or tricks I should know as a newbie, they are definitely welcome. Thanks.

  Read the article

• CharField values disappearing after save (readonly field)

  - by jamida

  I'm implementing simple "grade book" application where the teacher would be able to update the grades w/o being allowed to change the students' names (at least not on the update grade page). To do this I'm using one of the read-only tricks, the simplest one. The problem is that after the SUBMIT the view is re-displayed with 'blank' values for the students. I'd like the students' names to re-appear. Below is the simplest example that exhibits this problem. (This is poor DB design, I know, I've extracted just the relevant parts of the code to showcase the problem. In the real example, student is in its own table but the problem still exists there.) models.py class Grade1(models.Model): student = models.CharField(max_length=50, unique=True) finalGrade = models.CharField(max_length=3) class Grade1OForm(ModelForm): student = forms.CharField(max_length=50, required=False) def __init__(self, *args, **kwargs): super(Grade1OForm,self).__init__(*args, **kwargs) instance = getattr(self, 'instance', None) if instance and instance.id: self.fields['student'].widget.attrs['readonly'] = True self.fields['student'].widget.attrs['disabled'] = 'disabled' def clean_student(self): instance = getattr(self,'instance',None) if instance: return instance.student else: return self.cleaned_data.get('student',None) class Meta: model=Grade1 views.py from django.forms.models import modelformset_factory def modifyAllGrades1(request): gradeFormSetFactory = modelformset_factory(Grade1, form=Grade1OForm, extra=0) studentQueryset = Grade1.objects.all() if request.method=='POST': myGradeFormSet = gradeFormSetFactory(request.POST, queryset=studentQueryset) if myGradeFormSet.is_valid(): myGradeFormSet.save() info = "successfully modified" else: myGradeFormSet = gradeFormSetFactory(queryset=studentQueryset) return render_to_response('grades/modifyAllGrades.html',locals()) template <p>{{ info }}</p> <form method="POST" action=""> <table> {{ myGradeFormSet.management_form }} {% for myform in myGradeFormSet.forms %} {# myform.as_table #} <tr> {% for field in myform %} <td> {{ field }} {{ field.errors }} </td> {% endfor %} </tr> {% endfor %} </table> <input type="submit" value="Submit"> </form>

  Read the article

• Why is the Clojure Hello World program so slow compared to Java and Python?

  - by viksit

  Hi all, I'm reading "Programming Clojure" and I was comparing some languages I use for some simple code. I noticed that the clojure implementations were the slowest in each case. For instance, Python - hello.py def hello_world(name): print "Hello, %s" % name hello_world("world") and result, $ time python hello.py Hello, world real 0m0.027s user 0m0.013s sys 0m0.014s Java - hello.java import java.io.*; public class hello { public static void hello_world(String name) { System.out.println("Hello, " + name); } public static void main(String[] args) { hello_world("world"); } } and result, $ time java hello Hello, world real 0m0.324s user 0m0.296s sys 0m0.065s and finally, Clojure - hellofun.clj (defn hello-world [username] (println (format "Hello, %s" username))) (hello-world "world") and results, $ time clj hellofun.clj Hello, world real 0m1.418s user 0m1.649s sys 0m0.154s Thats a whole, garangutan 1.4 seconds! Does anyone have pointers on what the cause of this could be? Is Clojure really that slow, or are there JVM tricks et al that need to be used in order to speed up execution? More importantly - isn't this huge difference in performance going to be an issue at some point? (I mean, lets say I was using Clojure for a production system - the gain I get in using lisp seems completely offset by the performance issues I can see here). The machine used here is a 2007 Macbook Pro running Snow Leopard, a 2.16Ghz Intel C2D and 2G DDR2 SDRAM. BTW, the clj script I'm using is from here and looks like, #!/bin/bash JAVA=/System/Library/Frameworks/JavaVM.framework/Versions/1.6/Home/bin/java CLJ_DIR=/opt/jars CLOJURE=$CLJ_DIR/clojure.jar CONTRIB=$CLJ_DIR/clojure-contrib.jar JLINE=$CLJ_DIR/jline-0.9.94.jar CP=$PWD:$CLOJURE:$JLINE:$CONTRIB # Add extra jars as specified by `.clojure` file if [ -f .clojure ] then CP=$CP:`cat .clojure` fi if [ -z "$1" ]; then $JAVA -server -cp $CP \ jline.ConsoleRunner clojure.lang.Repl else scriptname=$1 $JAVA -server -cp $CP clojure.main $scriptname -- $* fi

  Read the article

• Table borders don't display properly when converted from HTML page into MS Word 2003

  - by Daria

  Hello everyone, I've got a bit of a complicated set up. I specialise in XSLT which I write for 3rd party system. All CSS looks fine in the browser. Now that system provides a button that converts my generated HTML into MS Word 2003. However, table borders don't convert as they appear in a Browser. There are lots of tables and they have different borders setup. For example there is one that uses only outside border and no borders inside it. When converting to MS Word, a table appears with ALL the borders in between cells. Which I don't want. I've tried search the Internet, but didn't come across anything useful. Maybe there are tips or tricks on how to set up tables borders so it's understood properly by MS Word. The third party said the following: "The system just passes the HTML created through the converter it finds in the installed version of Word". I would really appreciate any tips and help! Dasha

  Read the article

• Fastest Method to Learn Web Design for a Developer

  - by hekevintran

  I am a Web developer and in my projects I have noticed that my weakest point is not being good at the front-end design. Relying on other designers can be annoying if they are not able to produce as quickly as I want. My perspective on HTML/CSS is that it is basically a big hack that amazingly works. There are too many CSS and browser specific bugs/quirks to learn and remember them all without spending extreme amounts of time trying to untangle everything. Is there a fast track route to getting CSS into my brain? I have looked at some CSS books, but to me they really read as long lists of how to render things correctly in IE6 and how to make corners rounded. (Seriously why does it require so many tricks to make a sharp corner round? On any platform but the Web this would be called a major oversight.) Does there exist something that does the analogous to CSS that jQuery does for JavaScript? Using jQuery you don't need to know JavaScript well to make things that work. I am not interested in learning why IE6 does things in weird ways because I don't care about supporting it at all. I am more interested in a method of learning how to use CSS to do what I want without spending hours and hours reading obscure blogs.

  Read the article

• Specific programming text editor for simple open/close editing

  - by queen3

  I'm looking for very specific text editor: Closes on ESC, no project management or tabs Syntax highlighting - preferably with color themes (e.g. can apply different color themes without changing C# coloring definition) or, at least, can load/save themes; support for C/C#/XML/HTML/JavaScript/etc - common MS/.NET world - out of box Configurable keys, or: Shift-Tab shifts blocks XML/HTML auto-completion support - well, optional I use synplus plugin for Total Commander currently, but it has few drawbacks (e.g. crashes sometimes ;-), no auto-completion, etc). Basically I want fast Visual-Studio-like editor that I open, do edits, and then close using ESC. I remember I tried Notepad++, etc - most of them open files in tabs, don't close on ESC... - that is, behave like IDE. At least I've just downloaded Notepad++, it doesn't close on ESC even if I setup keybindings to do so. Autocompletion is optional (though it is to be simple as just tags completion), what I really look for is closing on ESC, not getting in the way with all the tabs and IDE-like, and good coloring. Plus shift-tab is must have for blocks manipulation. Update: any open-source one that I can easily tweak to close on ESC? ;-) Seems like ESC (and reasonable color highlighting) is the core requirement. I've just tried many editors - Programmer's Notepad, E, Crimson, etc - I can't set any of them to close on ESC. Any external tool to close selected program on ESC? ;-) UPDATE: Hm, found an awesome utility for my latest thought: http://www.autohotkey.com. Easy to setup to close any window on ESC (as well as many other tricks). Seems like the most tough requirements is gone - I can use ANY text editor ;-)

  Read the article

• How would you design a question/answer view (iPhone SDK)

  - by Aurélien Vallée

  I'm new to iPhone development, and I have a question on how to create a view for my application. The view should display a problem (using formatted/syntax highlighted text), and multiple possible answers. The user should be able to click on an answer to validate it. Currently, I am trying to use a UITableView embedding UIWebView as contentView. That allows me to display formatted text easily. The problem is that it is a real pain to compute and adjust the height of the cells. I have to preload the webview, call sizeToFit, get its height, and update the cell accordingly. This process should be done for the problem and the answers (as they are HTML formatted text too). It's such a pain that I am planning to switch to something else. I thought using only a big UIWebView and design everything in HTML. But I looked at some articles describing how to communicate between the HTML page and the ObjectiveC code. This seems to involve some awful tricks too... So... that's it, I don't really know what I should do. I guess some of you dealt with such things before, and would provide some greatly appreciated tips :)

  Read the article

• Are AJAX sites crawlable by search engines?

  - by frankadelic

  I had always assumed that AJAX-driven content was invisible to search engines. (i.e. content inserted into the DOM via XMLHTTPRequest) For example, in this site, the main content is loaded via AJAX request by the browser: http://www.trustedsource.org/query/terra.cl ...if you view this page with Javascript disabled, the main content area is blank. However, Google cache shows the full content after the AJAX load: http://74.125.155.132/search?q=cache:JqcT6EVDHBoJ:www.trustedsource.org/query/terra.cl+http://www.trustedsource.org/query/terra.cl&cd=1&hl=en&ct=clnk&gl=us So, apparently search engines do index content loaded by AJAX. Questions: Is this a new feature in search engines? Most postings on the web indicate that you have to publish duplicate static HTML content for search engines to find them. Are there any tricks to get an AJAX-driven content to be crawled by search engines (besides creating duplicate static HTML content). Will the AJAX-driven content be indexed if it is loaded from a separate subdomain? How about a separate domain?

  Read the article

• Help with Neuroph neural network

  - by user359708

  For my graduate research I am creating a neural network that trains to recognize images. I am going much more complex than just taking a grid of RGB values, downsampling, and and sending them to the input of the network, like many examples do. I actually use over 100 independently trained neural networks that detect features, such as lines, shading patterns, etc. Much more like the human eye, and it works really well so far! The problem is I have quite a bit of training data. I show it over 100 examples of what a car looks like. Then 100 examples of what a person looks like. Then over 100 of what a dog looks like, etc. This is quite a bit of training data! Currently I am running at about one week to train the network. This is kind of killing my progress, as I need to adjust and retrain. I am using Neuroph, as the low-level neural network API. I am running a dual-quadcore machine(16 cores with hyperthreading), so this should be fast. My processor percent is at only 5%. Are there any tricks on Neuroph performance? Or Java peroformance in general? Suggestions? I am a cognitive psych doctoral student, and I am decent as a programmer, but do not know a great deal about performance programming.

  Read the article

• Copy an entity in Google App Engine datastore in Python without knowing property names at 'compile'

  - by Gordon Worley

  In a Python Google App Engine app I'm writing, I have an entity stored in the datastore that I need to retrieve, make an exact copy of it (with the exception of the key), and then put this entity back in. How should I do this? In particular, are there any caveats or tricks I need to be aware of when doing this so that I get a copy of the sort I expect and not something else. ETA: Well, I tried it out and I did run into problems. I would like to make my copy in such a way that I don't have to know the names of the properties when I write the code. My thinking was to do this: #theThing = a particular entity we pull from the datastore with model Thing copyThing = Thing(user = user) for thingProperty in theThing.properties(): copyThing.__setattr__(thingProperty[0], thingProperty[1]) This executes without any errors... until I try to pull copyThing from the datastore, at which point I discover that all of the properties are set to None (with the exception of the user and key, obviously). So clearly this code is doing something, since it's replacing the defaults with None (all of the properties have a default value set), but not at all what I want. Suggestions?

  Read the article

• Most efficient way to check for DBNull and then assign to a variable?

  - by ilitirit

  This question comes up occasionally but I haven't seen a satisfactory answer. A typical pattern is (row is a DataRow): if (row["value"] != DBNull.Value) { someObject.Member = row["value"]; } My first question is which is more efficient (I've flipped the condition): row["value"] == DBNull.Value; // Or row["value"] is DBNull; // Or row["value"].GetType() == typeof(DBNull) // Or... any suggestions? This indicates that .GetType() should be faster, but maybe the compiler knows a few tricks I don't? Second question, is it worth caching the value of row["value"] or does the compiler optimize the indexer away anyway? eg. object valueHolder; if (DBNull.Value == (valueHolder = row["value"])) {} Disclaimers: row["value"] exists. I don't know the column index of the column (hence the column name lookup) I'm asking specifically about checking for DBNull and then assignment (not about premature optimization etc). Edit: I benchmarked a few scenarios (time in seconds, 10000000 trials): row["value"] == DBNull.Value: 00:00:01.5478995 row["value"] is DBNull: 00:00:01.6306578 row["value"].GetType() == typeof(DBNull): 00:00:02.0138757 Object.ReferenceEquals has the same performance as "==" The most interesting result? If you mismatch the name of the column by case (eg. "Value" instead of "value", it takes roughly ten times longer (for a string): row["Value"] == DBNull.Value: 00:00:12.2792374 The moral of the story seems to be that if you can't look up a column by it's index, then ensure that the column name you feed to the indexer matches the DataColumn's name exactly. Caching the value also appears to be nearly twice as fast: No Caching: 00:00:03.0996622 With Caching: 00:00:01.5659920 So the most efficient method seems to be: object temp; string variable; if (DBNull.Value != (temp = row["value"]) { variable = temp.ToString(); } This was a good learning experience.

  Read the article

• Can I ignore a SIGFPE resulting from division by zero?

  - by Mikeage

  I have a program which deliberately performs a divide by zero (and stores the result in a volatile variable) in order to halt in certain circumstances. However, I'd like to be able to disable this halting, without changing the macro that performs the division by zero. Is there any way to ignore it? I've tried using #include <signal.h> ... int main(void) { signal(SIGFPE, SIG_IGN); ... } but it still dies with the message "Floating point exception (core dumped)". I don't actually use the value, so I don't really care what's assigned to the variable; 0, random, undefined... EDIT: I know this is not the most portable, but it's intended for an embedded device which runs on many different OSes. The default halt action is to divide by zero; other platforms require different tricks to force a watchdog induced reboot (such as an infinite loop with interrupts disabled). For a PC (linux) test environment, I wanted to disable the halt on division by zero without relying on things like assert.

  Read the article

• When do you tag your software project?

  - by WilhelmTell of Purple-Magenta

  I realize there are various kinds of software projects: commercial (for John Doe) industrial (for Mr. Montgomery Burns) successful open-source (with audience larger than, say, 10 people) personal projects (with audience size in the vicinity of 1). each of which release a new version of their product on difference conditions. I'm particularly interested in the case of personal projects and open-source projects. When, or under what conditions, do you make a new release of any kind? Do you subscribe to a fixed recurring deadline such as every two weeks? Do you commit to a release of at least 10 minor fixes, or one major fix? Do you combine the two conditions such as at least one condition must hold, or both must hold? I reckon this is a subjective question. I ask this question in light of searching for tricks to keep my projects alive and kicking. Sometimes my projects are active but look as if they aren't because I don't have the confidence to make a release or a tag of any sort for a long time -- in the order of months.

  Read the article

• How can I work around the fact that in C++, sin(M_PI) is not 0?

  - by Adam Doyle

  In C++, const double Pi = 3.14159265; cout << sin(Pi); // displays: 3.58979e-009 it SHOULD display the number zero I understand this is because Pi is being approximated, but is there any way I can have a value of Pi hardcoded into my program that will return 0 for sin(Pi)? (a different constant maybe?) In case you're wondering what I'm trying to do: I'm converting polar to rectangular, and while there are some printf() tricks I can do to print it as "0.00", it still doesn't consistently return decent values (in some cases I get "-0.00") The lines that require sin and cosine are: x = r*sin(theta); y = r*cos(theta); BTW: My Rectangular - Polar is working fine... it's just the Polar - Rectangular Thanks! edit: I'm looking for a workaround so that I can print sin(some multiple of Pi) as a nice round number to the console (ideally without a thousand if-statements) edit: In case anyone's curious, this was what I landed on: double sin2(double theta) // in degrees { double s = sin(toRadians(theta)); if (fabs(s - (int)s) < 0.000001) { return floor(s + 0.5); } return s; } where toRadians() is a macro that converts to radians

  Read the article

• What is the 'page lifecycle' of an ASP.NET MVC page, compared to ASP.NET WebForms?

  - by Simon

  What is the 'page lifecycle' of an ASP.NET MVC page, compared to ASP.NET WebForms? I'm tryin to better understand this 'simple' question in order to determine whether or not existing pages I have in a (very) simple site can be easily converted from ASP.NET WebForms. Either a 'conversion' of the process below, or an alternative lifecycle would be what I'm looking for. What I'm currently doing: (yes i know that anyone capable of answering my question already knows all this -- i'm just tryin to get a comparison of the 'lifecycle' so i thought i'd start by filling in what we already all know) Rendering the page: I have a master page which contains my basic template I have content pages that give me named regions from the master page into which I put content. In an event handler for each content page I load data from the database (mostly read-only). I bind this data to ASP.NET controls representing grids, dropdowns or repeaters. This data all 'lives' inside the HTML generated. Some of it gets into ViewState (but I wont go into that too much!) I set properties or bind data to certain items like Image or TextBox controls on the page. The page gets sent to the client rendered as non-reusable HTML. I try to avoid using ViewState other than what the page needs as a minimum. Client side (not using ASP.NET AJAX): I may use JQuery and some nasty tricks to find controls on the page and perform operations on them. If the user selects from a dropdown -- a postback is generated which triggers a C# event in my codebehind. This event may go to the database, but whatever it does a completely newly generated HTML page ends up getting sent back to the client. I may use Page.Session to store key value pairs I need to reuse later So with MVC how does this 'lifecycle' change?

  Read the article

• Debug NAudio MP3 reading difference?

  - by Conrad Albrecht

  My code using NAudio to read one particular MP3 gets different results than several other commercial apps. Specifically: My NAudio-based code finds ~1.4 sec of silence at the beginning of this MP3 before "audible audio" (a drum pickup) starts, whereas other apps (Windows Media Player, RealPlayer, WavePad) show ~2.5 sec of silence before that same drum pickup. The particular MP3 is "Like A Rolling Stone" downloaded from Amazon.com. Tested several other MP3s and none show any similar difference between my code and other apps. Most MP3s don't start with such a long silence so I suspect that's the source of the difference. Debugging problems: I can't actually find a way to even prove that the other apps are right and NAudio/me is wrong, i.e. to compare block-by-block my code's results to a "known good reference implementation"; therefore I can't even precisely define the "error" I need to debug. Since my code reads thousands of samples during those 1.4 sec with no obvious errors, I can't think how to narrow down where/when in the input stream to look for a bug. The heart of the NAudio code is a P/Invoke call to acmStreamConvert(), which is a Windows "black box" call which I can't think how to error-check. Can anyone think of any tricks/techniques to debug this?

  Read the article

• Using LinqExtender to make OData feed fails

  - by BurningIce

  A pretty simple question, has anyone here tried to make a OData feed based on a IQueryable created with LinqExtender? I have created a simple Linq-provider that supports Where, Select, OrderBy and Take and wanted to expose it as an OData Feed. I keep getting an error though, and the Exception is a NullReference with the following StackTrace at System.Data.Services.Serializers.Serializer.GetObjectKey(Object resource, IDataServiceProvider provider, String containerName) at System.Data.Services.Serializers.Serializer.GetUri(Object resource, IDataServiceProvider provider, ResourceContainer container, Uri absoluteServiceUri) at System.Data.Services.Serializers.SyndicationSerializer.WriteEntryElement(IExpandedResult expanded, Object element, Type expectedType, Uri absoluteUri, String relativeUri, SyndicationItem target) at System.Data.Services.Serializers.SyndicationSerializer.<DeferredFeedItems>d__0.MoveNext() at System.ServiceModel.Syndication.Atom10FeedFormatter.WriteItems(XmlWriter writer, IEnumerable`1 items, Uri feedBaseUri) at System.ServiceModel.Syndication.Atom10FeedFormatter.WriteFeedTo(XmlWriter writer, SyndicationFeed feed, Boolean isSourceFeed) at System.ServiceModel.Syndication.Atom10FeedFormatter.WriteFeed(XmlWriter writer) at System.ServiceModel.Syndication.Atom10FeedFormatter.WriteTo(XmlWriter writer) at System.Data.Services.Serializers.SyndicationSerializer.WriteTopLevelElements(IExpandedResult expanded, IEnumerator elements, Boolean hasMoved) at System.Data.Services.Serializers.Serializer.WriteRequest(IEnumerator queryResults, Boolean hasMoved) at System.Data.Services.ResponseBodyWriter.Write(Stream stream) I've kinda narrowed it down to a issue where LinqExtender wraps every returned object, so that my object actually inherits itself - thats at least how it looks like in the debugger. These two queries are basicly the same. The first is the legacy-api where the OrderBy and Select is regular Linq to Objects. The second query is a "real" linq-provider made with LinqExtender. var db = CalendarDataProvider.GetCalendarEntriesByDate(DateTime.Now, DateTime.Now.AddMonths(1), Guid.Empty) .OrderBy(o => o.Title) .Select(o => new ODataCalendarEntry(o)); var query = new ODataCalendarEntryQuery() .Where(o => o.Start > DateTime.Now && o.End < DateTime.Now.AddMonths(1)) .OrderBy(o => o.Title); When returning db for the OData feed everything is fine, but returning query throws a NullRefenceException. I've tried all kind of tricks and even tried to project all the data into a new object like this, but still the same error return query.Select(o => new ODataCalendarEntry { Title = o.Title, Start = o.Start, End = o.End, Name = o.Name });

  Read the article

• Why do programmers have to learn for their whole lives and aren't you afraid of that?

  - by serg555

  Programming technologies are evolving so fast that programmers constantly have to learn more and more to catch up whether you want it or not. Often it is not just learning more in the same direction but starting from a scratch. Lets say you were a topnotch programmer in 1999 who quit for 10 years and went to a job interview in 2009 (funny even to imagine) - how much of your knowledge is still needed? And if we take a carpenter, engineer, doctor or even mathematician - they all are still good specialists after 10 years. So why programming is so not stable? Is it because it is just relatively new or because something important is still missing after 50 years and we can't find it to settle in that direction? Do you think after some time situation will change? Learning something new all the time is exciting and all, but it is starting to worry me that as I become older it will be harder and harder. After all "you can't teach an old dog new tricks" and I'm afraid that at the end I just end up behind college students and become one of those "cobol dinosaurs", only it will be probably "java dinosaurs" by that time.

  Read the article

• How can I add a portrait layout on top of a landscape Camera SurfaceView?

  - by user319919

  I need a Camera SurfaceView for my application. The camera should be set to fixed landscape view which is done by setting android:screenOrientation="landscape" for the activity in the AndroidManifest.xml. After doing some experiments and Google researches trying to use setRotation(int) inside the camera preview implementation, I came to the conclusion, that it is obviously the common practice to get a preview with correct behaviour. Now the camera preview itself looks fine for landscape orientation. But I need to have an overlay that holds a bunch of buttons. Due to usability the user interface should be in portrait view (or even better orientation aware). There seemed no other option to me, but to fix the activity screenOrientation, so that the camera preview looks normal (in portrait mode the whole view is streched and rotated to the left) Is there a workaround to get my buttons back to portrait orientation? Or another overall approach to deal with the camera view? Parameters.setRotation(int) obvisouly didnt work. I am quite new to the Android plattform programming. Of course I dont know much about the programming tricks and workarounds yet. I did a lot of research over the last two weeks, but couldnt find the right solution so far.

  Read the article

• Comet, responseText and memory usage

  - by ithcy

  Is there a way to clear out the responseText of an XHR object without destroying the XHR object? I need to keep a persistent connection open to a web server to feed live data to a browser. The problem is, there is a relatively large amount of data coming through (several hundred K per second constantly), so memory usage is a big problem, because this connection must remain open for at least several minutes. responseText gets very big very quickly, even though the JSON I send back has been crunched as small as it can get. Due to the way the server-side app works, if I use AJAX-style short polling and just destroy the XHR object when I'm done with it, I miss significant amounts of important data even in the few milliseconds it takes to parse the response, create a new XHR and send it out. I do not have the option to use overlapping requests, as the web server only accepts one connection at a time. (Don't ask.) So Comet is exactly the model I need. What I would like to do is parse each JSON chunk as it comes back from the server, and then clear out responseText so that I can keep using the same connection. However, responseText is read-only. It cannot be directly emptied by any method I have found. Is there a part of the picture I am missing here? Does anyone know any tricks I can use to free up responseText when I'm done reading it? Or is there another place the server responses can go? I am not including code because this is really almost a code-agnostic question. The Javascript routines that spawn the XHRs and handle the returned data are very, very simple.

  Read the article

• How do I make the following interaction with mySQL more efficient?

  - by Travis

  I've got an array that contains combinations of unique MySql IDs: For example: [ [1,10,11], [2,10], [3,10,12], [3,12,13,20], [4,12] ] In total there are a couple hundred different combinations of IDs. Some of these combinations are "valid" and some are not. For example, [1,10,11] may be a valid combination, whereas [3,10,12] may be invalid. Combinations are valid or invalid depending on how the data is arranged in the database. Currently I am using a SELECT statement to determine whether or not a specific combination of IDs is valid. It looks something like this: SELECT id1 FROM table WHERE id2 IN ($combination) GROUP BY id1 HAVING COUNT(distinct id2) = $number ...where $combination is one possible combination of IDs (eg 1,10,11) and $number is the number of IDs in that combination (in this case, 3). An invalid combination will return 0 rows. A valid combination will return 1 or more rows. However, to solve the entire set of possible combinations means looping a couple hundred SELECT statements, which I would rather not be doing. I am wondering: Are there any tricks for making this more efficient? Is it possible to submit the entire dataset to mySQL in one go, and have mySQL iterate through it? Any suggestions would be much appreciated. Thanks in advance!

  Read the article

< Previous Page | 113 114 115 116 117 118 119 120 121 122 123 124  | Next Page >