Array Creation - Error

[mikejfe]

Hi all.

I create an array using this code:

//Variables.h
extern int *g_x;                                    //x voxel vector
extern int *g_y;                                    //y voxel vector
extern int *g_z;                                    //z voxel vector
extern double ***g_xyz;                        //voxel contents (i.e. organ values)
 
 
 
//LoadFile.cpp
#include<string>
#include<fstream>
#include<iostream>
#include<Variables.h>
 
using namespace std;
 
// Voxel information arrays
double ***g_xyz;
int *g_x;
int *g_y;
int *g_z;
 
//Some other variable declerations
...
 
void callLoadFile()
{
// Ask user for input file information
cout << endl << "File to be loaded and array size (*.txt X Y Z): ";
cin >> filename >> g_numOfVoxelsX >> g_numOfVoxelsY >> g_numOfVoxelsZ;
 
// Create the voxel 3d array
g_xyz = new double**[g_numOfVoxelsX];
for (i = 0; i<=g_numOfVoxelsX; i++) {
     g_xyz[i] = new double*[g_numOfVoxelsY];
     for (j = 0; j<=g_numOfVoxelsY; j++) {
         g_xyz[i][j] = new double[g_numOfVoxelsZ];
         }
     }
 
//Rest of code
...
}
 

When I try and create an array of size 300 by 300 by 300, for example, everything works well. If I try anything larger than 475 by 475 by 475 though, my program crashes.

I've attempted to do some debugging by putting in comments. When I try 512 by 512 by 512, the program crashes at the point where it creates the 1 by 512 by 512.

If I run the compiler in debug mode (I'm using Dev-C++) and step past 1 by 512 by 512 and then let the program go, the array will be created with no problem.

I'm pretty new to C++ programming ... I didn't know if it was a problem of not having time to allocate the space, so I added a wait period - to no resolve. Are there inherent limitations in creating arrays of arbitrary size using this method?

Does anybody have any ideas?

Thanks!
-Michael

[mikejfe]

I might add that I'm using Windows XP, 1.7GHz Duo, 2GB of memory.

Thanks.

[Ganon11]

Well, I know that creating 512x512x512 entries is 134,217,728 doubles, which takes up 1,073,741,824 bytes (with an 8 byte sized double) - my computer, right now, has only 2,337,832,960 bytes of storage free, which is more than 2 GB (2.17 approx.). Assuming you have some 'stuff' on your computer, you probably don't have enough free memory to handle this much data.

[willakawill]

I might add that I'm using Windows XP, 1.7GHz Duo, 2GB of memory.

Thanks.

Hi. When you use the new operator in windows you are asking for a contiguous block of free memory just for your app. In this case (512x512x512) you are asking for 1,073,741,824 bytes of contiguous free memory. Aint gonna happen no matter how much memory you have installed.

I have 4Gb and I would normally run foul of windows at around requests for 800mb. Remember, it is not how much memory you have installed. It is how much contiguous (non interupted, in a row) memory windows can get hold of that counts

If you can't get away with using floats instead of doubles, try creating 2 arrays separately and split the load. I have done that with 5 different splits before and got it to work

[mikejfe]

Great. I'll try spliting the load up. Thank you for your help!

-Michael