hadamard matrix

[detfella]

Hi

What would the best method be to create a Hadamard matrix in C++?

0: 11111111111111111111111111111111
1: 11111111111111110000000000000000
2: 11111111000000000000000011111111
3: 11111111000000001111111100000000
4: 11110000000011111111000000001111
5: 11110000000011110000111111110000
6: 11110000111100000000111100001111
7: 11110000111100001111000011110000
8: 11000011110000111100001111000011
9: 11000011110000110011110000111100
10: 11000011001111000011110011000011
11: 11000011001111001100001100111100
12: 11001100001100111100110000110011
13: 11001100001100110011001111001100
14: 11001100110011000011001100110011
15: 11001100110011001100110011001100

I'd like to store the matrix in a 2 dimensional array with dimensions 16 x 32.

Is this correct so far..?

int f, N, had[16][32]; 
                 for (f=0; f<16; f++); 
                       for (N=0; N<32; N++); 
                             had[f][N] =

So i'm now looking to fill the array with the hadamard values and I don't know how to do this. Any help would be very much appreciated.

det

[MrWizard]

Are you having problems actually computing the hadamard matrix values? Or the coding behind it? Since you say you have a 16x32 matrix with only 2 values ( usually -1 and 1's but 0's and 1's is fine ), you can do a trick.

Just have an array of 16 integers and let the integer bits (assuming an integer is 4 bytes on your system ) stand for the rows. So if you decalred:

int Matrix[16];

then you are subscripting into the rows and then you can use bitwise manipulation to check individual bits. You could wrap this nicely in a class and save on storage. If storage isn't a primary concern to you then feel free to declare the 2D array.

[kuphryn]

One solution is dynamic allocation.

Kuphryn

[detfella]

thanks for the replies. Thanks for the pointer MrWizard that's just what i was looking for.