Help on calculate time taken to execute a function!!

[cylin]

Hi, I am currently doing a project regarding image processing. I had facing problem writing C++ code to calculate time taken to execute a function.
Can somebody help me on this. thanks.


#include "picture.h"
#include <iostream>

using namespace std;

int main()
{
int i;
int cnt = 0;

colour_picture_of_<unsigned char> in(240,320);
colour_picture_of_<unsigned char> out(240,320);

in.show("Input",0);
out.show("Output",0);

in.attach_camera();// Connect the picture to the camera
in.request_frame(); // Request frame

**************Start timer**************************
for (i = 1; i <= 10; i++ )
{
cout << "Frame " << cnt++ << endl;
}

**************End timer**************************

[willakawill]

Hi, I am currently doing a project regarding image processing. I had facing problem writing C++ code to calculate time taken to execute a function.
Can somebody help me on this. thanks.


#include "picture.h"
#include <iostream>

using namespace std;

int main()
{
int i;
int cnt = 0;

colour_picture_of_<unsigned char> in(240,320);
colour_picture_of_<unsigned char> out(240,320);

in.show("Input",0);
out.show("Output",0);

in.attach_camera();// Connect the picture to the camera
in.request_frame(); // Request frame

**************Start timer**************************
for (i = 1; i <= 10; i++ )
{
cout << "Frame " << cnt++ << endl;
}

**************End timer**************************

Hi. This is one way I use to do it. You must include 'atltime.h'

         CFileTime cftStart;
    CFileTime cftEnd;
    CFileTimeSpan cftLapsed;
    char message[200] = {0};
 
    cftStart = GetCurrentTime();
 
//put your code that you want to time here
 
    cftEnd = GetCurrentTime();
    cftLapsed = cftEnd - cftStart;
    sprintf_s(message, 200, "completed process in %d secs"
        , cftLapsed.GetTimeSpan() / 1000);
         MessageBoxA(message);
 

Regarding the / 1000
this will give you the elapsed time in seconds. Change it to 60000 if you want minutes and leave it out if you want milliseconds
Good luck

[macklin01]

Hi. This is one way I use to do it. You must include 'atltime.h' ...

GetCurrentTime(), CFileTime, etc. look very Microsoft-specific. A lot of image processing work/research isn't limited solely to MS platforms, and so something more cross-platform compatible may be useful. e.g.,

// ...
#include <ctime>
 
time_t TicTime;
time_t TocTime;
 
void TIC();
void TOC();
double StopwatchTimeInSeconds( void );
 
// ... 
 
int main( int argc, char* argv[] )
{
 // ...
 
 
 // start timing here.
 TIC();
 
 // code to time here
 
 // stop timing here
 TOC();
 
 // output stopwatch value 
 
 cout << StopwatchValueInSeconds() << " seconds to complete" << endl;
 
 return 0;
}
 
void TIC( void )
{ TicTime = time(NULL); }
 
void TOC( void )
{ TocTime = time(NULL); }
 
double StopwatchValueInSeconds( void )
{ return difftime(TocTime,TicTime); }
 

In fact, I use that very code to time functions in my cancer simulations. e.g.,

0 seconds for angiogenesis update
49 seconds for level set and geometry maintenance

You can also use clock() functions, but I've had more trouble with those on some linux/g++ combinations, for unknown reasons. -- Paul