float something[1000][1000]?

[rastkocvetkovic]

Why is this a problem in Visual Studio 6.0? The problem just crashes (Report Error to Microsoft). The size shouldn't be a problem - I think we've all seen arrays longer than 1000*1000.

Thank you for help!

 

[rastkocvetkovic]

Actually, try to compile this:

void OutputSomething() {
//float something[360][360]; //case ONE
flat something[359][359]; //case TWO
something[34][24] = 0.9;
printf("Output: %f\n\n", something[34][24]);
}

case ONE (parameter >= 360) doesn't work.
case TWO (parameter < 360) works.

360*360 < 2^17.
359*359 < 2^17. => there is no logical border in indexing!

 

[Temps]

I tried out your code (as a console application) and it worked for both cases.

I'm guessing that the problem lies with the fact that you are blowing the 'stack'. Each 'float' takes 4 bytes of stack so 1000*1000*4 = 4,000,000 bytes and 'default' stack size is only 1MB.

You can increase the stack size within the project settings but be careful if you are using incremental linking - the new stack size is ignored until a full link is performed.

Alternatively you can use EDITBIN to change the stack size outside of Visual Studio.

 

[mingis]

Don't use huge local arrays, allocate them dynamically using new.

 

[pankajkumar]

Hi mingis
Would you please give a sample to use array in pointers

 

[rastkocvetkovic]

yes, pankajkumar, i agree. that would be helpful. tnx in advance.

 

[pankajkumar]

Yes rastkocvetkovic I need a sample where i can allocate with new ,an array to a pointer.
and Temps is right
Make off &quot;Link Inceremently&quot; then ....
Project->Settings->Links->Outout--Reserve..and assign a new stack allocation in integer.
Of Course your code need stack size more spacious then default allocation

awaiting minigis's reply


use this code

 

[Temps]

To allocate dynamically use the following syntax for a float array of 1000 by 1000:-

float (*something)[1000];
something = new float[1000][1000];

something[34][24] = 0.9f;
printf(&quot;Output: %f\n\n&quot;, something[34][24]);

delete [] something; // for completeness

 

[pankajkumar]

Thanks Temps

 

[pankajkumar]

how to allocate in case of char arrays?

 

[Temps]

Same applies for any dynamically allocated multi-dimensional array. So for a 1000*1000 char array:-

char (*something)[1000];
something = new char[1000][1000];

something[34][24] = 'z';
printf(&quot;Output: %c\n\n&quot;, something[34][24]);

delete [] something;