Search Results

Search found 983 results on 40 pages for 'calculations'.

Page 31/40 | < Previous Page | 27 28 29 30 31 32 33 34 35 36 37 38  | Next Page >

  • C programming - How to print numbers with a decimal component using only loops?

    - by californiagrown
    I'm currently taking a basic intro to C programming class, and for our current assignment I am to write a program to convert the number of kilometers to miles using loops--no if-else, switch statements, or any other construct we haven't learned yet are allowed. So basically we can only use loops and some operators. The program will generate three identical tables (starting from 1 kilometer through the input value) for one number input using the while loop for the first set of calculations, the for loop for the second, and the do loop for the third. I've written the entire program, however I'm having a bit of a problem with getting it to recognize an input with a decimal component. Here is what I have for the while loop conversions: #include <stdio.h> #define KM_TO_MILE .62 main (void) { double km, mi, count; printf ("This program converts kilometers to miles.\n"); do { printf ("\nEnter a positive non-zero number"); printf (" of kilometers of the race: "); scanf ("%lf", &km); getchar(); }while (km <= 1); printf ("\n KILOMETERS MILES (while loop)\n"); printf (" ========== =====\n"); count = 1; while (count <= km) { mi = KM_TO_MILE * count; printf ("%8.3lf %14.3lf\n", count, mi); ++count; } getchar(); } The code reads in and converts integers fine, but because the increment only increases by 1 it won't print a number with a decimal component (e.g. 3.2, 22.6, etc.). Can someone point me in the right direction on this? I'd really appreciate any help! :)

    Read the article

  • power and modulo on the fly for big numbers

    - by user unknown
    I raise some basis b to the power p and take the modulo m of that. Let's assume b=55170 or 55172 and m=3043839241 (which happens to be the square of 55171). The linux-calculator bc gives the results (we need this for control): echo "p=5606;b=55171;m=b*b;((b-1)^p)%m;((b+1)^p)%m" | bc 2734550616 309288627 Now calculating 55170^5606 gives a somewhat large number, but since I have to do a modulooperation, I can circumvent the usage of BigInt, I thought, because of: (a*b) % c == ((a%c) * (b%c))%c i.e. (9*7) % 5 == ((9%5) * (7%5))%5 => 63 % 5 == (4 * 2) %5 => 3 == 8 % 5 ... and a^d = a^(b+c) = a^b * a^c, therefore I can divide b+c by 2, which gives, for even or odd ds d/2 and d-(d/2), so for 8^5 I can calculate 8^2 * 8^3. So my (defective) method, which always cut's off the divisor on the fly looks like that: def powMod (b: Long, pot: Int, mod: Long) : Long = { if (pot == 1) b % mod else { val pot2 = pot/2 val pm1 = powMod (b, pot, mod) val pm2 = powMod (b, pot-pot2, mod) (pm1 * pm2) % mod } } and feeded with some values, powMod (55170, 5606, 3043839241L) res2: Long = 1885539617 powMod (55172, 5606, 3043839241L) res4: Long = 309288627 As we can see, the second result is exactly the same as the one above, but the first one looks quiet different. I'm doing a lot of such calculations, and they seem to be accurate as long as they stay in the range of Int, but I can't see any error. Using a BigInt works as well, but is way too slow: def calc2 (n: Int, pri: Long) = { val p: BigInt = pri val p3 = p * p val p1 = (p-1).pow (n) % (p3) val p2 = (p+1).pow (n) % (p3) print ("p1: " + p1 + " p2: " + p2) } calc2 (5606, 55171) p1: 2734550616 p2: 309288627 (same result as with bc) Can somebody see the error in powMod?

    Read the article

  • C++ Iterator Pipelining Designs

    - by Kirakun
    Suppose we want to apply a series of transformations, int f1(int), int f2(int), int f3(int), to a list of objects. A naive way would be SourceContainer source; TempContainer1 temp1; transform(source.begin(), source.end(), back_inserter(temp1), f1); TempContainer2 temp2; transform(temp1.begin(), temp1.end(), back_inserter(temp2), f2); TargetContainer target; transform(temp2.begin(), temp2.end(), back_inserter(target), f3); This first solution is not optimal because of the extra space requirement with temp1 and temp2. So, let's get smarter with this: int f123(int n) { return f3(f2(f1(n))); } ... SourceContainer source; TargetContainer target; transform(source.begin(), source.end(), back_inserter(target), f123); This second solution is much better because not only the code is simpler but more importantly there is less space requirement without the intermediate calculations. However, the composition f123 must be determined at compile time and thus is fixed at run time. How would I try to do this efficiently if the composition is to be determined at run time? For example, if this code was in a RPC service and the actual composition--which can be any permutation of f1, f2, and f3--is based on arguments from the RPC call.

    Read the article

  • Which web solution should I use for my project?

    - by BenIOs
    I'm going to create a fairly large (from my point of view anyway) web project with a friend. We will create a site with roads and other road related info. Our calculations is that we will have around 100k items in our database. Each item will contain some information like location, name etc. (about 30 thing each). We are counting on having a few hundred thousand unique visitors per month. The 100k items and their locations (that will be searchable) will be the main part of the page but we will also have some articles, comments, news and later on some more social functions (accounts, forums, picture uploads etc.). We were going to use Google AppEngine to develop our project since it is really scalable and free (at least for a while). But I'm actually starting to doubt that AppEngine is right for us. It seems to be for webbapps and not sites like ours. Which system (language/framework etc.) would you guys recommend us to use? It doesn't really mater if we know the language since before (we like learning new stuff) but it would be good if it's something that is future proof.

    Read the article

  • iOS OpenGL ES 1.1 jerky animation using CADisplayLink (reboot fixes for a while)

    - by timthecoder
    I'm using OpenGL ES 1.1 and CADisplayLink to animate a 3d scene. If the iOS device has been rebooted fairly recently, the animation is smooth and the time delta between two displayLink.timestamp calls is fairly even. But after a few hours or days of the iOS device being used and my app is sometimes run a few times, the animation becomes jerky and the time deltas ramp up and then reset to a lower value only to ramp up again. Like this: 2012-09-01 23:42:58.770 [2678:707] dt= 0.021139 2012-09-01 23:42:58.787 [2678:707] dt= 0.022183 2012-09-01 23:42:58.804 [2678:707] dt= 0.023223 2012-09-01 23:42:58.820 [2678:707] dt= 0.024270 2012-09-01 23:42:58.837 [2678:707] dt= 0.009679 2012-09-01 23:42:58.853 [2678:707] dt= 0.010750 2012-09-01 23:42:58.870 [2678:707] dt= 0.011766 2012-09-01 23:42:58.887 [2678:707] dt= 0.012806 2012-09-01 23:42:58.903 [2678:707] dt= 0.013847 2012-09-01 23:42:58.920 [2678:707] dt= 0.014890 2012-09-01 23:42:58.937 [2678:707] dt= 0.015933 2012-09-01 23:42:58.953 [2678:707] dt= 0.016976 2012-09-01 23:42:58.970 [2678:707] dt= 0.018011 2012-09-01 23:42:58.987 [2678:707] dt= 0.019055 2012-09-01 23:42:59.003 [2678:707] dt= 0.020097 2012-09-01 23:42:59.020 [2678:707] dt= 0.021143 2012-09-01 23:42:59.037 [2678:707] dt= 0.022181 2012-09-01 23:42:59.054 [2678:707] dt= 0.023222 2012-09-01 23:42:59.071 [2678:707] dt= 0.024288 2012-09-01 23:42:59.087 [2678:707] dt= 0.009624 2012-09-01 23:42:59.103 [2678:707] dt= 0.010728 2012-09-01 23:42:59.121 [2678:707] dt= 0.011763 2012-09-01 23:42:59.137 [2678:707] dt= 0.012808 2012-09-01 23:42:59.153 [2678:707] dt= 0.013847 2012-09-01 23:42:59.170 [2678:707] dt= 0.014891 2012-09-01 23:42:59.187 [2678:707] dt= 0.016002 2012-09-01 23:42:59.203 [2678:707] dt= 0.016979 2012-09-01 23:42:59.220 [2678:707] dt= 0.018016 2012-09-01 23:42:59.237 [2678:707] dt= 0.019042 2012-09-01 23:42:59.253 [2678:707] dt= 0.020099 2012-09-01 23:42:59.270 [2678:707] dt= 0.021138 2012-09-01 23:42:59.287 [2678:707] dt= 0.022185 2012-09-01 23:42:59.304 [2678:707] dt= 0.023222 2012-09-01 23:42:59.320 [2678:707] dt= 0.024265 2012-09-01 23:42:59.337 [2678:707] dt= 0.009681 2012-09-01 23:42:59.354 [2678:707] dt= 0.010736 And then if the iOS device is rebooted the animation is smooth again. The problem even occurs on my menu screen when almost no game related calculations are going on in the UpdateAnimation() function. I don't understand what is going on and why a fresh reboot will always fix this problem for a while.

    Read the article

  • Vectorize matrix operation in R

    - by Fernando
    I have a R x C matrix filled to the k-th row and empty below this row. What i need to do is to fill the remaining rows. In order to do this, i have a function that takes 2 entire rows as arguments, do some calculations and output 2 fresh rows (these outputs will fill the matrix). I have a list of all 'pairs' of rows to be processed, but my for loop is not helping performance: # M is the matrix # nrow(M) and k are even, so nLeft is even M = matrix(1:48, ncol = 3) # half to fill k = nrow(M)/2 # simulate empty rows to be filled M[-(1:k), ] = 0 cat('before fill') print(M) # number of empty rows to fill nLeft = nrow(M) - k nextRow = k + 1 # list of rows to process (could be any order of non-empty rows) idxList = matrix(1:k, ncol = 2) for ( i in 1 : (nLeft / 2)) { row1 = M[idxList[i, 1],] row2 = M[idxList[i, 2],] # the two columns in 'results' will become 2 rows in M # fake result, return 2*row1 and 3*row2 results = matrix(c(2*row1, 3*row2), ncol = 2) # fill the matrix M[nextRow, ] = results[, 1] nextRow = nextRow + 1 M[nextRow, ] = results[, 2] nextRow = nextRow + 1 } cat('after fill') print(M) I tried to vectorize this, but failed... appreciate any help on improving this code, thanks!

    Read the article

  • Why does reusing arrays increase performance so significantly in c#?

    - by Willem
    In my code, I perform a large number of tasks, each requiring a large array of memory to temporarily store data. I have about 500 tasks. At the beginning of each task, I allocate memory for an array : double[] tempDoubleArray = new double[M]; M is a large number depending on the precise task, typically around 2000000. Now, I do some complex calculations to fill the array, and in the end I use the array to determine the result of this task. After that, the tempDoubleArray goes out of scope. Profiling reveals that the calls to construct the arrays are time consuming. So, I decide to try and reuse the array, by making it static and reusing it. It requires some additional juggling to figure out the minimum size of the array, requiring an extra pass through all tasks, but it works. Now, the program is much faster (from 80 sec to 22 sec for execution of all tasks). double[] tempDoubleArray = staticDoubleArray; However, I'm a bit in the dark of why precisely this works so well. Id say that in the original code, when the tempDoubleArray goes out of scope, it can be collected, so allocating a new array should not be that hard right? I ask this because understanding why it works might help me figuring out other ways to achieve the same effect, and because I would like to know in what cases allocation gives performance issues.

    Read the article

  • Query with UDF works in Access but gives Undefined function in expression (Err 3085) in Excel

    - by ronwest
    I have an Access table with a date/time field. I wanted to make a composite Key field out of the date/time field and 3 other text fields in the same format as the matching Key field in another database. So I concatenated the 3 text fields and wrote a User-Defined-Function in a Module to output the date field as a string in the format "YYYYMMDD". Public Function YYYYMMDD(dteDate As Date) As String YYYYMMDD = Format(dteDate, "YYYYMMDD") End Function I can then successfully run my queries in Access and it all works fine. But when I set up some DAO code in Excel and try to run the query that works fine within Access... db.Execute "qryMake_tblValsDailyAccount" ...Excel gives me the "Undefined function in expression. (Error 3085)" error. To me this is a bug in Excel and/or Access, because the (Excel) client shouldn't need to know anything about the internal calculations that normally take place perfectly in the (Access) server when in isolation. Excel should send the querydef (name with no parameters) to the server, let the server do its work then receive the answers. Why does it need to get involved with a function internal to the server? Does anyone know a way around this?

    Read the article

  • converting a UTC time to a local time zone in Java

    - by aloo
    I know this subject has been beaten to death but after searching for a few hours to this problem I had to ask. My Problem: do calculations on dates on a server based on the current time zone of a client app (iphone). The client app tells the server, in seconds, how far away its time zone is away from GMT. I would like to then use this information to do computation on dates in the server. The dates on the server are all stored as UTC time. So I would like to get the HOUR of a UTC Date object after it has been converted to this local time zone. My current attempt: int hours = (int) Math.floor(secondsFromGMT / (60.0 * 60.0)); int mins = (int) Math.floor((secondsFromGMT - (hours * 60.0 * 60.0)) / 60.0); String sign = hours > 0 ? "+" : "-"; Calendar now = Calendar.getInstance(); TimeZone t = TimeZone.getTimeZone("GMT" + sign + hours + ":" + mins); now.setTimeZone(t); now.setTime(someDateTimeObject); int hourOfDay = now.get(Calendar.HOUR_OF_DAY); The variables hour and mins represent the hour and mins the local time zone is away from GMT. After debugging this code - the variables hour, mins and sign are correct. The problem is hourOfDay does not return the correct hour - it is returning the hour as of UTC time and not local time. Ideas?

    Read the article

  • Calculating distance between two X,Y coordinates

    - by Umopepisdn
    I am writing a tool for a game that involves calculating the distance between two coordinates on a spherical plane 500 units across. That is, [0,0] through [499,499] are valid coordinates, and [0,0] and [499,499] are also right next to each other. Currently, in my application, I am comparing the distance between a city with an [X,Y] location respective to the user's own [X,Y] location, which they have configured in advance. To do this, I found this algorithm, which kind of works: Math.sqrt ( dx * dx + dy * dy ); Because sorting a paged list by distance is a useful thing to be able to do, I implemented this algorithm in a MySQL query and have made it available to my application using the following part of my SELECT statement: SQRT( POW( ( ".strval($sourceX)." - cityX ) , 2 ) + POW( ( ".strval($sourceY)." - cityY ) , 2 ) ) AS distance This works fine for many calculations, but does not take into account the fact that [0,0] and [499,499] are kitty-corner to one another. Is there any way I can tweak this algorithm to generate an accurate distance, given that 0 and 499 are adjacent? Thanks, -Umo

    Read the article

  • Mixing stored procedures and ORM

    - by Jason
    The company I work for develops a large application which is almost entirely based on stored procedures. We use classic ASP and SQL Server and the major part of the business logic is contained inside those stored procedures. For example, (I know, this is bad...) a single stored procedure can be used for different purposes (insert, update, delete, make some calculations, ...). Most of the time, a stored procedure is used for operations on related tables, but this is not always the case. We are planning to move to ASP.NET in a near future. I have read a lot of posts on StackOverflow recommending that I move the business logic outside the database. The thing is, I have tried to convince the people who takes the decisions at our company and there is nothing I can do to change their mind. Since I want to be able to use the advantages of object-oriented programming, I want to map the tables to actual classes. So far, my solution is to use an ORM (Entity Framework 4 or nHibernate) to avoid mapping the objects manually (mostly to retrieve the data) and use some kind of Data Access Layer to call the existing stored procedures (for saving). I want your advice on this. Do you think it is a good solution? Any ideas?

    Read the article

  • Data conversion from accelerometer

    - by mrigendra
    Hi all I am working on an accelerometer bma220 , and its datasheet says that data is in 2's complement form.So what i had to do was getting that 8 bit data in any 8 bit signed char and done. the bma220 have an 8 bit register of which first 6 bits are data and last two are zero. void properdata(int16_t *msgData) { printf("\nin proper data\n"); int16_t temp, i; for(i=0; i<3; i++) { temp = *(msgData + i); printf("temp = %d sense = %d\n", temp, sense); temp = temp >> 2; // only 6 bits data temp = temp / sense; //decimal value * .0625 = value in g printf("temp = %d\n", temp); } } in this program i am taking data in a unsigned variable msgdata and doing all the calculations on a signed variable. I just need to know if this is the correct way to convert data?

    Read the article

  • C# properties: How are they instantiated?

    - by Pedery
    Hi! This might be a pretty straightforward question, but I'm trying to understand some of the internal workings of the compilation. Very simply put, imagine an arbitrary object being instantiated. This object is then allocated on the heap. The object has a property of type PointF (which is value type), with a get and a set method. Imagine the get and the set method containing a few calculations for doing their work. How and where (stack/heap) and when is this code instantiated? This is the background for this question: I'm writing get and set methods for an object and these methods need to be accessed very frequently. The get and set code in itself is rather massive so I feared that in a worst case scenario the methods would be instantiated as an object or a value type with all internal code for every access of the property. On the other hand the code is probably instantiated when the main object is created and the CPU is simply told to jmp to the property code start. Anyway, this is what I want to have clarified.

    Read the article

  • How to store and collect data for mining such information as most viewed for last 24 hours, last 7 d

    - by Kirzilla
    Hello, Let's imagine that we have high traffic project (a tube site) which should provide sorting using this options (NOT IN REAL TIME). Number of videos is about 200K and all information about videos is stored in MySQL. Number of daily video views is about 1.5KK. As instruments we have Hard Disk Drive (text files), MySQL, Redis. Views top viewed top viewed last 24 hours top viewed last 7 days top viewed last 30 days top rated last 365 days How should I store such information? The first idea is to log all visits to text files (single file per hour, for example visits_20080101_00.log). At the beginning of each hour calculate views per video for previous hour and insert this information into MySQL. Then recalculate totals (for last 24 hours) and update statistics in tables. At the beginning of every day we have to do the same but recalculate for last 7 days, last 30 days, last 365 days. This method seems to be very poor for me because we have to store information about last 365 days for each video to make correct calculations. Is there any other good methods? Probably, we have to choose another instruments for this? Thank you.

    Read the article

  • Turn based synchronization between threads

    - by Amarus
    I'm trying to find a way to synchronize multiple threads having the following conditions: * There are two types of threads: 1. A single "cyclic" thread executing an infinite loop to do cyclic calculations 2. Multiple short-lived threads not started by the main thread * The cyclic thread has a sleep duration between each cycle/loop iteration * The other threads are allowed execute during the inter-cycle sleep of the cyclic thread: - Any other thread that attempts to execute during an active cycle should be blocked - The cyclic thread will wait until all other threads that are already executing to be finished Here's a basic example of what I was thinking of doing: // Somewhere in the code: ManualResetEvent manualResetEvent = new ManualResetEvent(true); // Allow Externally call CountdownEvent countdownEvent = new CountdownEvent(1); // Can't AddCount a CountdownEvent with CurrentCount = 0 void ExternallyCalled() { manualResetEvent.WaitOne(); // Wait until CyclicCalculations is having its beauty sleep countdownEvent.AddCount(); // Notify CyclicCalculations that it should wait for this method call to finish before starting the next cycle Thread.Sleep(1000); // TODO: Replace with actual method logic countdownEvent.Signal(); // Notify CyclicCalculations that this call is finished } void CyclicCalculations() { while (!stopCyclicCalculations) { manualResetEvent.Reset(); // Block all incoming calls to ExternallyCalled from this point forward countdownEvent.Signal(); // Dirty workaround for the issue with AddCount and CurrentCount = 0 countdownEvent.Wait(); // Wait until all of the already executing calls to ExternallyCalled are finished countdownEvent.Reset(); // Reset the CountdownEvent for next cycle. Thread.Sleep(2000); // TODO: Replace with actual method logic manualResetEvent.Set(); // Unblock all threads executing ExternallyCalled Thread.Sleep(1000); // Inter-cycles delay } } Obviously, this doesn't work. There's no guarantee that there won't be any threads executing ExternallyCalled that are in between manualResetEvent.WaitOne(); and countdownEvent.AddCount(); at the time the main thread gets released by the CountdownEvent. I can't figure out a simple way of doing what I'm after, and almost everything that I've found after a lengthy search is related to producer/consumer synchronization which I can't apply here.

    Read the article

  • C++: Calculate probability percentage during each iteration

    - by Mur Quirk
    Can't seem to get this to work. The idea is to calculate the percentage of heads and tails after each count, accumulating after each iteration. Except I keep getting nan% for my calculations. Anybody see what I'm doing wrong? void flipCoin(time_t seconds, int flipCount){ vector<int> flips; float headCount = 0; float tailCount = 0; double headProbability = double((headCount/(headCount + tailCount))*100); double tailProbability = double((tailCount/(headCount + tailCount))*100); for (int i=0; i < flipCount; i++) { int flip = rand() % (HEADS - TAILS + 1) + TAILS; flips.push_back(flip); if (flips[i] == 1) { tailCount++; cout << "Tail Percent: " << tailProbability << "%" << endl; }else{ headCount++; cout << "Head Percent: " << headProbability << "%" << endl; } } }

    Read the article

  • How do I call C++/CLI (.NET) DLLs from standard, unmanaged non-.NET applications?

    - by tronjohnson
    In the unmanaged world, I was able to write a __declspec(dllexport) or, alternatively, use a .DEF file to expose a function to be able to call a DLL. (Because of name mangling in C++ for the __stdcall, I put aliases into the .DEF file so certain applications could re-use certain exported DLL functions.) Now, I am interested in being able to expose a single entry-point function from a .NET assembly, in unmanaged-fashion, but have it enter into .NET-style functions within the DLL. Is this possible, in a simple and straight-forward fashion? What I have is a third-party program that I have extended through DLLs (plugins) that implement some complex mathematics. However, the third-party program has no means for me to visualize the calculations. I want to somehow take these pre-written math functions, compile them into a separate DLL (but using C++/CLI in .NET), but then add hooks to the functions so I can render what's going on under the hood in a .NET user control. I'm not sure how to blend the .NET stuff with the unmanaged stuff, or what to Google to accomplish this task. Specific suggestions with regard to the managed/unmanaged bridge, or alternative methods to accomplish the rendering in the manner I have described would be helpful. Thank you.

    Read the article

  • 2 dimensional arrays passed to a function in c++

    - by John Marcus
    I'm working on doing calculations in a two dimensional array but keep getting a nasty error. i call the function by : if(checkArray(array)) and try to pass it in like this: bool checkArray(double array[][10]) //or double *array[][10] to no avail the error is error: cannot convert ‘double ()[(((unsigned int)(((int)n) + -0x00000000000000001)) + 1)]’ to ‘double’ for argument ‘1’ to ‘bool checkArray(double*)’ code snippet //array declaration int n = 10; double array[n][n]; //function call to pass in array while(f != 25) { cout<<endl; cout<<endl; if(checkArray(array)) //this is the line of the error { cout<<"EXIT EXIT EXIT"<<endl; } f++; } //function declaration bool checkArray(double *array)//, double newArray[][10]) { double length = sizeof(array); for(int i = 0; i < length; i++) for(int j = 0; j < length;j++) { double temp = array[i][j]; } }

    Read the article

  • [MVC] logic before dispatcher + controller?

    - by Spoonface
    I believe for a typical MVC web application the router / dispatcher routine is used to decide which controller is loaded based primarily on the area requested in the url by the user. However, in addition to checking the url query string, I also like to use the dispatcher to check whether the user is currently logged in or not to decide which controller is loaded. For example if they are logged in and request the login page, the dispatcher would load their account instead. But is this a fairly non-standard design? Would it violate MVC in any way? I only ask as the examples I've read through this weekend have had no major calculations performed before the dispatcher routine, and commonly check whether the user is logged in or not per controller, and then redirect where necessary. But to me it seems odd to redirect a logged in user from the login area to account area if you could just load the account controller in the first place? I hope I've explained my consternation well enough, but could anyone offer some details on how they handle logged in users, and similar session data?

    Read the article

  • Reload a UITable on the fly when editing a UITextField inside one of the cells

    - by Saze
    I have a UITable containing some customs UITableCells. Those cells contain a few UILabels and a UITextField. The datasource of the table comes from a main controller's property. (This controller is also the delegate and the dataSource for the table). Here's a simplified screenshot of the UI: Now, I need to update "on the fly" the content of all the UILabels when the user edits one of the UITextFields. To do so, at the I am listening to the "Editing Changed" event at the UITextField level. This triggers the following action: - (IBAction) editChangeHandler: (id) sender { MyAppDelegate *delegate = [[UIApplication sharedApplication] delegate]; [[delegate.viewController.myDataSourceArray objectAtIndex:self.rowIndex] setANumber: [theTextField.text intValue]]; [delegate.viewController reloadRows]; } The reloadRows method in the viewController is as such: - (void) reloadRows { NSLog(@"called reloadRows"); //perform some calculations on the data source objects here... [theUITable reloadData]; } My problem here is that whenever the user changes the value in the field, the reloadRows method is successfully called, so is apparently the reloadData but it also causes the keyboard to be dismissed. So in the end, the user can only touch one key when editing the TextField before the keyboard is dismissed and the table reloaded. Does anybody knows a solution to this or have experienced the same issue?

    Read the article

  • C read X bytes from a file, padding if needed

    - by Hunter McMillen
    I am trying to read in an input file 64 bits at a time, then do some calculations on those 64 bits, the problem is I need to convert the ascii text to hexadecimal characters. I have searched around but none of the answers posted seem to work for my situation. Here is what I have: int main(int argc, int * argv) { char buffer[9]; FILE *f; unsigned long long test; if(f = fopen("input2.txt", "r")) { while( fread(buffer, 8, 1, f) != 0) //while not EOF read 8 bytes at a time { buffer[8] = '\0'; test = strtoull(buffer, NULL, 16); //interpret as hex printf("%llu\n", test); printf("%s\n", buffer); } fclose(f); } } For an input like this: "testing string to hex conversion" I get results like this: 0 testing 0 string t 0 o hex co 0 nversion Where I would expect: 74 65 73 74 69 6e 67 20 <- "testing" in hex testing 73 74 72 69 6e 67 20 74 <- "string t" in hex string t 6f 20 68 65 78 20 63 6f <- "o hex co" in hex o hex co 6e 76 65 72 73 69 6f 6e <- "nversion" in hex nversion Can anyone see where I misstepped?

    Read the article

  • How can I integrate advanced computations into a database field?

    - by ciclistadan
    My biological research involves the measurement of a cellular structure as it changes length throughout the course of observation (capturing images every minute for several hours). As my data sets have become larger I am trying to store them in an Access database, from which I would like to perform various queries about their changes in size. I know that the SELECT statement can incorporate some mathematical permutations, but I have been unable to incorporate many of my necessary calculations (probably due to my lack of knowledge). For example, one calculation involves determining the rate of change during specifically defined periods of growth. This calculation is entirely dependent on the raw data saved in the table, therefore I didn't this it would be appropriate to just calculate it in excel prior to entry into the field. So my question is, what would be the most appropriate method of performing this calculation. Should I attempt to string together a huge SELECT calculation in my QUERY, or is there a way to use another language (I know perl?) which can be called to populate the new query field? I'm not looking for someone to write the code, just where is it appropriate to incorporate each step. Also, I am currently using Office Access but would be interested in any mySQL answers as I may be moving to this platform at a later date. Thanks all!

    Read the article

  • C++: Help with cin difference between Linux and Windows

    - by Krashman5k
    I have a Win32 console program that I wrote and it works fine. The program takes input from the user and performs some calculations and displays the output - standard stuff. For fun, I am trying to get the program to work on my Fedora box but I am running into an issue with clearing cin when the user inputs something that does not match my variable type. Here is the code in question: void CParameter::setPrincipal() { double principal = 0.0; cout << endl << "Please enter the loan principal: "; cin >> principal; while(principal <= 0) { if (cin.fail()) { cin.clear(); cin.ignore(INT_MAX, '\n'); } else { cout << endl << "Plese enter a number greater than zero. Please try again." << endl; cin >> principal; } } m_Parameter = principal; } This code works in Windows. For example, if the user tries to enter a char data type (versus double) then the program informs the user of the error, resets cin, and allows the user another opportunity to enter a valid value. When I move this code to Fedora, it compiles fine. When I run the program and enter an invalid data type, the while loop never breaks to allow the user to change the input. My questions are; how do I clear cin when invalid data is inputted in the Fedora environment? Also, how should I write this code so it will work in both environments (Windows & Linux)? Thanks in advance for your help!

    Read the article

  • Regex preg_match issue with commas

    - by Serge Sf
    This is my code to pre_match when an amount looks like this: $ 99.00 and it works if (preg_match_all('/[$]\s\d+(\.\d+)?/', $tout, $matches)) { $tot2 = $matches[0]; $tot2 = preg_replace("/\\\$/", '', $tot2);} I need to do the same thing for a amount that looks like this (with a comma): $ 99,00 Thank you for your help (changing dot for comma do not help, there is an "escape" thing I do not understand... Idealy I need to preg_match any number that looks like an amount with dot or commas and with or without dollar sign before or after (I know, it's a lot to ask :) since on the result form I want to scan there are phone and street numbers... UPDATE (For some reason I cannot comment on replies) : To test properly, I need to preg_replace the comma by a dot (since we are dealings with sums, I don't think calculations can be done on numbers with commas in it). So to clarify my question, I should say : I need to transform, let's say "$ 200,24" to "200.24". (could be amounts bettween 0.10 to 1000.99) : $tot2 = preg_replace("/\\\$/", '', $tot2);} (this code just deals with the $ (it works), I need adaptation to deal also with the change of (,) for (.))

    Read the article

  • Calculating with a variable outside of its bounds in C

    - by aquanar
    If I make a calculation with a variable where an intermediate part of the calculation goes higher then the bounds of that variable type, is there any hazard that some platforms may not like? This is an example of what I'm asking: int a, b; a=30000; b=(a*32000)/32767; I have compiled this, and it does give the correct answer of 29297 (well, within truncating error, anyway). But the part that worries me is that 30,000*32,000 = 960,000,000, which is a 30-bit number, and thus cannot be stored in a 16-bit int. The end result is well within the bounds of an int, but I was expecting that whatever working part of memory would have the same size allocated as the largest source variables did, so an overflow error would occur. This is just a small example to show my problem, I am trying to avoid using floating points by making the fraction be a fraction of the max amount able to be stored in that variable (in this case, a signed integer, so 32767 on the positive side), because the embedded system I'm using I believe does not have an FPU. So how do most processors handle calculations out of the bounds of the source and destination variables?

    Read the article

< Previous Page | 27 28 29 30 31 32 33 34 35 36 37 38  | Next Page >