Search Results

Search found 27016 results on 1081 pages for 'entry point'.

Page 44/1081 | < Previous Page | 40 41 42 43 44 45 46 47 48 49 50 51  | Next Page >

  • x86-64 long double precision

    - by aaa
    hello. What is the actual precision of long double on Intel 64-bit platforms? is it 80 bits padded to 128 or actual 128 bit? if former, besides going gmp, is there another option to achieve true 128 precision?

    Read the article

  • Drive a POS printer via USB in c#

    - by JDibble
    Any ideas how i can best drive a USB POS printer from c#. POS printers are usually serial, TCP/IP or USB based. I know how to accomplish serial and TCP/IP but have no idea about communications through USB in C#. I know that there is a layer available from Microsoft called POS.NET, but I want to try and avoid using this. Any ideas or any C# libraries that people can recomend would be really appreciated. Thanks

    Read the article

  • CSS3 new features...whats the point?

    - by benhowdle89
    I've been reading a lot of ways recently of how to avoid having to use Photoshop for things like gradients and shadows on buttons, when you can use CSS3 Box Shadow for such features. Now this is great, but obviously legacy browsers and most IE browsers don't yet implement CSS3 features, so my question is, why save yourself extra work in Photoshop when you can use CSS3 but then HAVE to use Photoshop for other browsers to see the desired effects? Isn't that just extra work?

    Read the article

  • Collision point of 2 curves in a 3d-room

    - by Frank
    Hello, i am programming a small game for quite some time. We started coding a small FPS-Shooter inside of a project at school to get a bit experience using directX. I dont know why, but i couldnt stop the project and started programming at home aswell. At the moment i am trying to create some small AI. Of cause thats definatlly not easy, but thats my personal goal anyways. The topic could prolly fill multiple books hehe. I've got the walking part of my bots done so far. They walk along a scriped path. I am not working on the "aiming" of the bots. While programming that i hit on some math problem i couldnt solve yet. I hope of your input on this to help me get further. Concepts, ideas and everything else are highly appreciated. Problem: Calculate the position (D3DXVECTOR3) where the curve of the projectile (depends on gravity, speed), hit the curved of the enemys walking path (depends on speed). We assume that the enemy walks in a constant line. Known variables: float projectilSpeed = 2000 m/s //speed of the projectile per second float gravitation = 9.81 m/s^2 //of cause the gravity lol D3DXVECTOR3 targetPosition //position of the target stored in a vector (x,y,z) D3DXVECTOR3 projectilePosition //position of the projectile D3DXVECTOR3 targetSpeed //stores the change of the targets position in the last second Variabledefinition ProjectilePosition at time of collision = ProjectilePos_t TargetPosition at time of collision = TargetPos_t ProjectilePosition at time 0, now = ProjectilePos_0 TargetPosition at time 0, now = TargetPos_0 Time to impact = t Aim-angle = theta My try: Found a formular to calculate "drop" (Drop of the projectile based on the gravity) on Wikipedia: float drop = 0.5f * gravity * t * t The speed of the projectile has a horizontal and a vertical part.. Found a formular for that on wikipedia aswell: ProjectilVelocity.x = projectilSpeed * cos(theta) ProjectilVelocity.y = projectilSpeed * sin(theta) So i would assume this is true for the projectile curve: ProjectilePos_t.x = ProjectilePos_0.x + ProjectileSpeed * t ProjectilePos_t.y = ProjectilePos_0.y + ProjectileSpeed * t + 0.5f * gravity * t * t ProjectilePos_t.z = ProjectilePos_0.z + ProjectileSpeed * t The target walk with a constant speed, so we can determine his curve by this: TargetPos_t = TargetPos_0 + TargetSpeed * D3DXVECTOR3(t, t, t) Now i dont know how to continue. I have to solve it somehow to get a hold on the time to impact somehow. As a basic formular i could use: float time = distanz / projectileSpeed But that wouldnt be truly correct as it would assume a linear "Trajectory". We just find this behaivor when using a rocket. I hope i was able to explain the problem as much as possible. If there are questions left, feel free to ask me! Greets from germany, Frank

    Read the article

  • Determine Android phone's proximity to known point while conserving power

    - by ahsteele
    I am trying to determine if an Android user has had a close proximity to a list of predetermined locations. I'd like to do this with the least amount of drain on the phone's battery. The two mechanisms I see for accomplishing this are proximity alerts and requesting location updates. What are the pros and cons of the two methods? Will one have less affect on the battery than the other? In either case I would guess the specific location manager used would affect power usage (existing Stack Overflow answer).

    Read the article

  • Can bad stuff happen when dividing 1/a very small float?

    - by Jeremybub
    If I want to check that positive float A is less than the inverse square of another positive float B (in C99), could something go wrong if B is very small? I could imagine checking it like if(A<1/(B*B)) but if B is small enough, would this possibly result in infinity? If that were to happen, would the code still work correctly in all situations? in a similar vein, I might do if(1/A>B*B) Which might be slightly better because B*B might be zero if B is small (is this true?) Finally, a solution that I can't imagine being wrong is if(sqrt(1/A)>B) Which I don't think would ever result in zero division, but still might be problematic if A is close to zero. So basically, my questions are Can 1/X ever be infinity if X is greater than zero (but small)? Can X*X ever be zero if X is greater than zero? Will comparisons with infinity work the way I would expect them to?

    Read the article

  • How do calculators work with precision?

    - by zoul
    Hello! I wonder how calculators work with precision. For example the value of sin(M_PI) is not exactly zero when computed in double precision: #include <math.h> #include <stdio.h> int main() { double x = sin(M_PI); printf("%.20f\n", x); // 0.00000000000000012246 return 0; } Now I would certainly want to print zero when user enters sin(p). I can easily round somewhere on 1e–15 to make this particular case work, but that’s a hack, not a solution. When I start to round like this and the user enters something like 1e–20, they get a zero back (because of the rounding). The same thing happens when the user enters 1/10 and hits the = key repeatedly — when he reaches the rounding treshold, he gets zero. And yet some calculators return plain zero for sin(p) and at the same time they can work with expressions such as (1e–20)/10 comfortably. Where’s the trick?

    Read the article

  • How to point to jdni.properties file to set properties in Java

    - by prosseek
    I can use System.getProperties() method to set properties in Java. System.getProperties().put("java.naming.factory.initial", "fr.dyade.aaa.jndi2.client.NamingContextFactory"); System.getProperties().put("java.naming.factory.host", "localhost"); System.getProperties().put("java.naming.factory.port", "16400"); How can I get the same effect by reading the properties stored in a file? When I have a jdni.properties with the following content: java.naming.factory.initial fr.dyade.aaa.jndi2.client.NamingContextFactory java.naming.factory.host localhost java.naming.factory.port 16400 How can I teach Java to read them as properties?

    Read the article

  • calculating a gps coordinate given a point, bearing and distance

    - by user530509
    Hello, I have a problem which draws my back in some project for some time now. Im basically looking to trap a polygon using x,y points drawn by some script ive written. lat1,lon1 are the center gps cords of the polygon and im looking for its surrounding polygon. here is a part of my code in python: def getcords(lat1,lon1,dr,bearing): lat2=asin(sin(lat1)*cos(dr)+cos(lat1)*sin(dr)*cos(bearing)) lon2=lon1+atan2(sin(bearing)*sin(dr)*cos(lat1),cos(dr)-sin(lat1)*sin(lat2)) return [lat2,lon2] my input goes like this: lat1,lon1 - are given in decimal degrees. -dr is the angular computed by dividing the distance in miles by the earth's -raiuds(=3958.82) -bearing between 0-360 degrees. however for the input getcorsds1(42.189275,-76.85823,0.5/3958.82,30) i get [-1.3485899508698462, -76.8576637627568], however [42.2516666666667,-76.8097222222222] is the right answer. as for the angular distance i calculate it simply by dividing the distance in miles by the earth's raiuds(=3958.82). anybody?

    Read the article

  • Feed paper on POS Printer C#

    - by evargas
    I've been trying to programatically feed the paper on a pos printer (Epson TM-U220D). The problem I have is that the last line of the document don't get printed, instead, it is printed as the first line of the next document printed. I tried POS for .NET sending the "ESC|flF" command, also tried to send the raw esc/pos command using the serial port, but it doesn't work. Any ideas?

    Read the article

  • Typecasting a floating value or using the math.h floor* functions?

    - by nobody
    Hi, I am coding up an implementation of Interpolation Search in C. The question is actually rather simple, I need to use the floating operations to do linear interpolation to find the correct index which will eventually be an integer result. In particular my probe index is: t = i + floor((((k-low)/(high-low)) * (j-i))); where, i,j,k,t are unsigned ints, and high,low are doubles. Would this be equivalent to: t = i + (unsigned int)(((k-low)/(high-low)) * (j-i)); Is there any reason I would actually want to use math.h floor* functions over just a simple (int) typecast?

    Read the article

  • Why might different computers calculate different arithmetic results in VB.NET?

    - by Eyal
    I have some software written in VB.NET that performs a lot of calculations, mostly extracting jpegs to bitmaps and computing calculations on the pixels like convolutions and matrix multiplication. Different computers are giving me different results despite having identical inputs. What might be the reason? Edit: I can't provide the algorithm because it's proprietary but I can provide all the relevant operations: ULong \ ULong (Turuncating division) Bitmap.Load("filename.bmp') (Load a bitmap into memory) Bitmap.GetPixel(Integer, Integer) (Get a pixel's brightness) Double + Double Double * Double Math.Sqrt(Double) Math.PI Math.Cos(Double) ULong - ULong ULong * ULong ULong << ULong List.OrderBy(Of Double)(Func) Hmm... Is it possible that OrderBy is using a non-stable QuickSort and that QuickSort is using a random pivot? Edit: Just tested, nope. The sort is stable.

    Read the article

  • Mercurial: Diff current source vs source at point in time

    - by Marcus
    I know how to view all changes in a changeset.. But let's say you update your source, you do a pull and you get 3 new changesets. How can you compare the current state of the remote repository (with the 3 changesets checked in) vs. the current source (on your local machine)? I'd like to do this using the visual diff tool which I currently have configured (Examdiff or Kdiff3).

    Read the article

  • How to compare two floating-point values in shell script

    - by Reem
    I had to do a division in shell script and the best way was: result1=`echo "scale=3; ($var1 / $total) * 100"| bc -l` result2=`echo "scale=3; ($var2 / $total) * 100"| bc -l` but I want to compare the values of $result1 and $result2 Using if test $result1 -lt $result2 or if [ $result1 -gt $result2 ] didn't work :( Any idea how to do that?

    Read the article

  • Float Conversion Issue

    - by user1407570
    I have an issue after converted a float from a string, the result of my operation is null The NSLogs give the right value but vitesseMoyenne is equal to null -(void)setVitesseMoyenne:(float)uneDistanceTotale:(NSString*)unTempsTotal { //float tempEnFloat = [unTempsTotal floatValue]; NSLog(@"%@",unTempsTotal); float calculVitesseMoyenne = uneDistanceTotale / [unTempsTotal floatValue]; NSLog(@"%f",calculVitesseMoyenne); vitesseMoyenne = [NSString stringWithFormat:@"%f", calculVitesseMoyenne]; } Can you see what is wrong ?

    Read the article

  • PHP math gets crazy, need explanation, my brain is melting

    - by derei
    I know that playing with php float can give strange results if you try to add "goats + apples", but please take a look to the following case: $val = 1232.81; $p1 = 1217.16; $p2 = 15.65; $sum = $p1 + $p2; $dif = $val - $sum; echo $dif; It will give you -2.2737367544323E-13 ... yeah, ALMOST zero, but then why it doesn't say 0 ? This freaks me out big time. Please, I need some valid explanation.

    Read the article

  • C/C++ - Convert 24-bit signed integer to float

    - by e-t172
    I'm programming in C++. I need to convert a 24-bit signed integer (stored in a 3-byte array) to float (normalizing to [-1.0,1.0]). The platform is MSVC++ on x86 (which means the input is little-endian). I tried this: float convert(const unsigned char* src) { int i = src[2]; i = (i << 8) | src[1]; i = (i << 8) | src[0]; const float Q = 2.0 / ((1 << 24) - 1.0); return (i + 0.5) * Q; } I'm not entirely sure, but it seems the results I'm getting from this code are incorrect. So, is my code wrong and if so, why?

    Read the article

  • Swap bits in c++ for a double

    - by hidayat
    Im trying to change from big endian to little endian on a double. One way to go is to use double val, tmp = 5.55; ((unsigned int *)&val)[0] = ntohl(((unsigned int *)&tmp)[1]); ((unsigned int *)&val)[1] = ntohl(((unsigned int *)&tmp)[0]); But then I get a warning: "dereferencing type-punned pointer will break strict-aliasing rules" and I dont want to turn this warning off. Another way to go is: #define ntohll(x) ( ( (uint64_t)(ntohl( (uint32_t)((x << 32) >> 32) )) << 32) | ntohl( ((uint32_t)(x >> 32)) ) ) val = (double)bswap_64(unsigned long long(tmp)); //or val = (double)ntohll(unsigned long long(tmp)); But then a lose the decimals. Anyone know a good way to swap the bits on a double without using a for loop?

    Read the article

< Previous Page | 40 41 42 43 44 45 46 47 48 49 50 51  | Next Page >