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  • Using SSIS, how do you read a datetime field into a variable that is of Data Type string?

    - by Mark Kadlec
    This one has bugged me for the longest time and a great question to ask the Stackoverflow users I think. I have a rather large SSIS flow that uses a string variable to store the datetime. I would now like to dynamically read the datetime value from the database, but how would you construct the SSIS to do this? My first obvious thought would be to simply execute a SQL task to get the datetime and store it in the variable, but got the "differs from the current variable type" error. Is there a simple way to convert the database datetime into a String variable? Any help from the community would be appreciated,

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  • If I don't odr-use a variable, can I have multiple definitions of it across translation units?

    - by sftrabbit
    The standard seems to imply that there is no restriction on the number of definitions of a variable if it is not odr-used (§3.2/3): Every program shall contain exactly one definition of every non-inline function or variable that is odr-used in that program; no diagnostic required. It does say that any variable can't be defined multiple times within a translation unit (§3.2/1): No translation unit shall contain more than one definition of any variable, function, class type, enumeration type, or template. But I can't find a restriction for non-odr-used variables across the entire program. So why can't I compile something like the following: // other.cpp int x; // main.cpp int x; int main() {} Compiling and linking these files with g++ 4.6.3, I get a linker error for multiple definition of 'x'. To be honest, I expect this, but since x is not odr-used anywhere (as far as I can tell), I can't see how the standard restricts this. Or is it undefined behaviour?

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  • C++: is it safe to read an integer variable that's being concurrently modified without locking?

    - by Hongli
    Suppose that I have an integer variable in a class, and this variable may be concurrently modified by other threads. Writes are protected by a mutex. Do I need to protect reads too? I've heard that there are some hardware architectures on which, if one thread modifies a variable, and another thread reads it, then the read result will be garbage; in this case I do need to protect reads. I've never seen such architectures though. This question assumes that a single transaction only consists of updating a single integer variable so I'm not worried about the states of any other variables that might also be involved in a transaction.

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  • How to check how many characters in variable, and add space between characters in that var?

    - by Camran
    I have a 'price' variable that contains some integer number from a MySQL database. I want to check how many numbers the 'price' variable contains, and add a space in the variable depending on how many numbers. See below: Example: If 'price' is 150000 I would like the output to be 150 000 (notice the space). OR, if it is 19000 I would like it to output 19 000... How would you do this the easiest way?

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  • Sum variable range of cells using "today's" date as starting point.

    - by Jason
    How do you sum a variable range of cells based upon today's date in MS Excel 2003. Spreadsheet format: Variable range = # of days to sum Date range = listed in row 1, 1 day per cell (example A1=1/1/10, B1=1/2/10, C1=1/3/10....) Numbers to be summed - listed in row 2, X number per cell (example A2=8, B2=6, C2=1.....) example problem: IF variable range = 2 & Current Date = 1/2/10 then...Sum(b2:c2)=7 I am able to sum the entire row based upon current date using the following formula but am not able to add the variable range to the sum function. =SUMIF(A1:C1,"="&TODAY(),A2:C2)

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  • How can I use a variable as a jQuery option value?

    - by mattgorecki
    I currently have jQuery code that looks like this: if ($.url.param("s") == "error") { $.gritter.add({ title: 'Error!', text: $.url.param('message') }); } I'm checking to see if the request variable s exists in the url (ie. http://example.com/?s=error&message=this%20is%20my%20message and then showing a popup message that contains information from request variable message. The popup works just fine, but the message variable isn't populated, the plugin asks for a string as a value for the text option. What is the proper way to grab the message variable?

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  • How do you create a cbuffer or global variable that is gpu modifiable?

    - by bobobobo
    I'm implementing tonemapping in a pixel shader, for hdr lighting. The vertex shader outputs vertices with colors. I need to find the max color and save it in a global. However when I try and write the global in my hlsl code, //clamp the max color below by this color clamp( maxColor, output.color, float4( 1e6,1e6,1e6,1e6 ) ) ; I see: error X3025: global variables are implicitly constant, enable compatibility mode to allow modification What is the correct way to declare a shader global in d3d11 that the vertex shader can write to, and the pixel shader can read? I realize this is a bit tough since the vertex shaders are supposed to run in parallel, and introducing a shader global that they all write to means a lock..

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  • Constant game speed independent of variable FPS in OpenGL with GLUT?

    - by Nazgulled
    I've been reading Koen Witters detailed article about different game loop solutions but I'm having some problems implementing the last one with GLUT, which is the recommended one. After reading a couple of articles, tutorials and code from other people on how to achieve a constant game speed, I think that what I currently have implemented (I'll post the code below) is what Koen Witters called Game Speed dependent on Variable FPS, the second on his article. First, through my searching experience, there's a couple of people that probably have the knowledge to help out on this but don't know what GLUT is and I'm going to try and explain (feel free to correct me) the relevant functions for my problem of this OpenGL toolkit. Skip this section if you know what GLUT is and how to play with it. GLUT Toolkit: GLUT is an OpenGL toolkit and helps with common tasks in OpenGL. The glutDisplayFunc(renderScene) takes a pointer to a renderScene() function callback, which will be responsible for rendering everything. The renderScene() function will only be called once after the callback registration. The glutTimerFunc(TIMER_MILLISECONDS, processAnimationTimer, 0) takes the number of milliseconds to pass before calling the callback processAnimationTimer(). The last argument is just a value to pass to the timer callback. The processAnimationTimer() will not be called each TIMER_MILLISECONDS but just once. The glutPostRedisplay() function requests GLUT to render a new frame so we need call this every time we change something in the scene. The glutIdleFunc(renderScene) could be used to register a callback to renderScene() (this does not make glutDisplayFunc() irrelevant) but this function should be avoided because the idle callback is continuously called when events are not being received, increasing the CPU load. The glutGet(GLUT_ELAPSED_TIME) function returns the number of milliseconds since glutInit was called (or first call to glutGet(GLUT_ELAPSED_TIME)). That's the timer we have with GLUT. I know there are better alternatives for high resolution timers, but let's keep with this one for now. I think this is enough information on how GLUT renders frames so people that didn't know about it could also pitch in this question to try and help if they fell like it. Current Implementation: Now, I'm not sure I have correctly implemented the second solution proposed by Koen, Game Speed dependent on Variable FPS. The relevant code for that goes like this: #define TICKS_PER_SECOND 30 #define MOVEMENT_SPEED 2.0f const int TIMER_MILLISECONDS = 1000 / TICKS_PER_SECOND; int previousTime; int currentTime; int elapsedTime; void renderScene(void) { (...) // Setup the camera position and looking point SceneCamera.LookAt(); // Do all drawing below... (...) } void processAnimationTimer(int value) { // setups the timer to be called again glutTimerFunc(TIMER_MILLISECONDS, processAnimationTimer, 0); // Get the time when the previous frame was rendered previousTime = currentTime; // Get the current time (in milliseconds) and calculate the elapsed time currentTime = glutGet(GLUT_ELAPSED_TIME); elapsedTime = currentTime - previousTime; /* Multiply the camera direction vector by constant speed then by the elapsed time (in seconds) and then move the camera */ SceneCamera.Move(cameraDirection * MOVEMENT_SPEED * (elapsedTime / 1000.0f)); // Requests to render a new frame (this will call my renderScene() once) glutPostRedisplay(); } void main(int argc, char **argv) { glutInit(&argc, argv); (...) glutDisplayFunc(renderScene); (...) // Setup the timer to be called one first time glutTimerFunc(TIMER_MILLISECONDS, processAnimationTimer, 0); // Read the current time since glutInit was called currentTime = glutGet(GLUT_ELAPSED_TIME); glutMainLoop(); } This implementation doesn't fell right. It works in the sense that helps the game speed to be constant dependent on the FPS. So that moving from point A to point B takes the same time no matter the high/low framerate. However, I believe I'm limiting the game framerate with this approach. Each frame will only be rendered when the time callback is called, that means the framerate will be roughly around TICKS_PER_SECOND frames per second. This doesn't feel right, you shouldn't limit your powerful hardware, it's wrong. It's my understanding though, that I still need to calculate the elapsedTime. Just because I'm telling GLUT to call the timer callback every TIMER_MILLISECONDS, it doesn't mean it will always do that on time. I'm not sure how can I fix this and to be completely honest, I have no idea what is the game loop in GLUT, you know, the while( game_is_running ) loop in Koen's article. But it's my understanding that GLUT is event-driven and that game loop starts when I call glutMainLoop() (which never returns), yes? I thought I could register an idle callback with glutIdleFunc() and use that as replacement of glutTimerFunc(), only rendering when necessary (instead of all the time as usual) but when I tested this with an empty callback (like void gameLoop() {}) and it was basically doing nothing, only a black screen, the CPU spiked to 25% and remained there until I killed the game and it went back to normal. So I don't think that's the path to follow. Using glutTimerFunc() is definitely not a good approach to perform all movements/animations based on that, as I'm limiting my game to a constant FPS, not cool. Or maybe I'm using it wrong and my implementation is not right? How exactly can I have a constant game speed with variable FPS? More exactly, how do I correctly implement Koen's Constant Game Speed with Maximum FPS solution (the fourth one on his article) with GLUT? Maybe this is not possible at all with GLUT? If not, what are my alternatives? What is the best approach to this problem (constant game speed) with GLUT? I originally posted this question on Stack Overflow before being pointed out about this site. The following is a different approach I tried after creating the question in SO, so I'm posting it here too. Another Approach: I've been experimenting and here's what I was able to achieve now. Instead of calculating the elapsed time on a timed function (which limits my game's framerate) I'm now doing it in renderScene(). Whenever changes to the scene happen I call glutPostRedisplay() (ie: camera moving, some object animation, etc...) which will make a call to renderScene(). I can use the elapsed time in this function to move my camera for instance. My code has now turned into this: int previousTime; int currentTime; int elapsedTime; void renderScene(void) { (...) // Setup the camera position and looking point SceneCamera.LookAt(); // Do all drawing below... (...) } void renderScene(void) { (...) // Get the time when the previous frame was rendered previousTime = currentTime; // Get the current time (in milliseconds) and calculate the elapsed time currentTime = glutGet(GLUT_ELAPSED_TIME); elapsedTime = currentTime - previousTime; /* Multiply the camera direction vector by constant speed then by the elapsed time (in seconds) and then move the camera */ SceneCamera.Move(cameraDirection * MOVEMENT_SPEED * (elapsedTime / 1000.0f)); // Setup the camera position and looking point SceneCamera.LookAt(); // All drawing code goes inside this function drawCompleteScene(); glutSwapBuffers(); /* Redraw the frame ONLY if the user is moving the camera (similar code will be needed to redraw the frame for other events) */ if(!IsTupleEmpty(cameraDirection)) { glutPostRedisplay(); } } void main(int argc, char **argv) { glutInit(&argc, argv); (...) glutDisplayFunc(renderScene); (...) currentTime = glutGet(GLUT_ELAPSED_TIME); glutMainLoop(); } Conclusion, it's working, or so it seems. If I don't move the camera, the CPU usage is low, nothing is being rendered (for testing purposes I only have a grid extending for 4000.0f, while zFar is set to 1000.0f). When I start moving the camera the scene starts redrawing itself. If I keep pressing the move keys, the CPU usage will increase; this is normal behavior. It drops back when I stop moving. Unless I'm missing something, it seems like a good approach for now. I did find this interesting article on iDevGames and this implementation is probably affected by the problem described on that article. What's your thoughts on that? Please note that I'm just doing this for fun, I have no intentions of creating some game to distribute or something like that, not in the near future at least. If I did, I would probably go with something else besides GLUT. But since I'm using GLUT, and other than the problem described on iDevGames, do you think this latest implementation is sufficient for GLUT? The only real issue I can think of right now is that I'll need to keep calling glutPostRedisplay() every time the scene changes something and keep calling it until there's nothing new to redraw. A little complexity added to the code for a better cause, I think. What do you think?

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  • Should *'s go next to the type or the variable name? [closed]

    - by derekerdmann
    Possible Duplicate: int* i; or int *i; or int * i; When working in C or C++, how should pointers be declared? Like this: char* derp; or this: char *derp; I typically use the first method, because the variable is a character pointer, but I know that it can create confusion when declaring multiple variables at once: char* herp, derp; herp becomes a character pointer, while derp is just a character. I know it often comes down to coding style, but which one is "better?" Should I sacrifice clarity to eliminate potential confusion?

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  • where to define variable for a for each loop?

    - by David
    can you please advise me why my first code attempt didn't work : public void listAllFiles() { for(String filename : files) { int position = 0; System.out.println(position + ": " + filename); position = position + 1; } } it kept printing position at 0 without iterating position but it seems to work after i did it this way: public void listAllFiles() { int position = 0; for(String filename : files) { System.out.println(position + ": " + filename); position = position + 1; } } I don't understand why the position + 1 was not being executed, is it because we are not meant to define variables inside for loops or am i missing something in my code.

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  • Why do most of us use 'i' as a loop counter variable?

    - by kprobst
    Has anyone thought about why so many of us repeat this same pattern using the same variable names? for (int i = 0; i < foo; i++) { // ... } It seems most code I've ever looked at uses i, j, k and so on as iteration variables. I suppose I picked that up from somewhere, but I wonder why this is so prevalent in software development. Is it something we all picked up from C or something like that? Just an itch I've had for a while in the back of my head.

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  • Why do most of us use 'i' as a loop counter variable?

    - by kprobst
    Has anyone thought about why so many of us repeat this same pattern using the same variable names? for (int i = 0; i < foo; i++) { // ... } It seems most code I've ever looked at uses i, j, k and so on as iteration variables. I suppose I picked that up from somewhere, but I wonder why this is so prevalent in software development. Is it something we all picked up from C or something like that? Just an itch I've had for a while in the back of my head.

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  • Why do you have to manually type variable names while debugging?

    - by SoboLAN
    I've seen this in a lot of IDEs (even in the most popular and heavily used ones, like Visual Studio): if you want to watch a variable's value, you have to manually type its name in the Watches section of the debugger. Why can't there just be a list of all of them with checkboxes next to them ? The developer can then just check the box next to the one he wants to watch and that's it. Variables with identical names can probably be numbered in some way (for example a, b, x(1), x(2), c, etc. I've seen some exceptions to this (NetBeans or BlueJ), but there are exceptions to everything, right ? Maybe it's a stupid question, maybe not, but I've always wondered why this is so.

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  • How to set PATH variable on Mac OS so that even non-terminal apps see it?

    - by dehmann
    I need to add a directory to my PATH variable on Mac OS. I added it in .bash_profile and .profile, and that works for the terminal. But Emacs (http://emacsformacosx.com) still does not use the new PATH variable. (I'm trying to run latex from emacs, but it's not finding the command in my /usr/local/bin, which I'm trying to add to the PATH ...) I even logged out and back in, but still no luck. Any suggestions?

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  • Need helping creating a loop in R. Have many similarly named variables I have to apply the same func

    - by user335897
    I am using a dataset w/variables that have very similar names. I have to apply the same functions to 13 variables at a time and I'm trying to shorten the code, instead of doing each variable individually. q01a.F=factor(q01a) q01b.F=factor(q01b) q01c.F=factor(q01c) q01d.F=factor(q01d) q01e.F=factor(q01e) q01f.F=factor(q01f) q01g.F=factor(q01g) q01h.F=factor(q01h) q01i.F=factor(q01i) q01j.F=factor(q01j) q01k.F=factor(q01k) q01l.F=factor(q01l) q01m.F=factor(q01m) Suggestions?

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  • ¿Que riesgo hay en usar extract con las variables superglobales de php?

    - by Carlos Montalvo
    Hola usando estas funciones, que riesgo corro en tener problemas de seguridad, es necesesario usar extract() o hay alguna manera mejor de convertir las variables superglobales (array) en trozos de variables. if ( get_magic_quotes_gpc() ) { $_GET = stripslashes( $_GET ); $_POST =stripslashes( $_POST ); } function vars_globals($value = '') { if (is_array ( $value )) $r = &$value; else parse_str ( $value, $r ); return $r; } $r = vars_globals( $_GET ); extract($r, EXTR_SKIP);

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  • C#: why have all static methods/variables in a non-static class?

    - by Craig Johnston
    I have come across a class which is non-static, but all the methods and variables are static. Eg: public class Class1 { private static string String1 = "one"; private static string String2 = "two"; public static void PrintStrings(string str1, string str2) { ... All the variables are static across all instances, so there is no point having separate instances of the class. Is there any reason to create a class such as this?

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