""" A simple example to show how to access a 3D scipy_base.numerix array.  One
example shows how to access the scipy_base.numerix array using blitz type
converters and the other shows how it can be done without using blitz
by accessing the scipy_base.numerix array data directly.

"""

import weave
from weave import converters
import scipy_base.numerix

def create_array():
    """Creates a simple 3D scipy_base.numerix array with unique values at each
    location in the matrix.

    """    
    rows, cols, depth = 2, 3, 4
    arr = scipy_base.numerix.zeros((rows, cols, depth), 'i')
    count = 0
    for i in range(rows):
        for j in range(cols):
            for k in range(depth):
                arr[i,j,k] = count
                count += 1
    return arr


def pure_inline(arr):
    """Prints the given 3D array by accessing the raw scipy_base.numerix data and
    without using blitz converters.

    Notice the following:
      1. '\\n' to escape generating a newline in the C++ code.
      2. rows, cols = Narr[0], Narr[1].
      3. Array access using arr[(i*cols + j)*depth + k].
      
    """
    
    code = """
    int rows = Narr[0];
    int cols = Narr[1];
    int depth = Narr[2];    
    for (int i=0; i < rows; i++)
    {
        for (int j=0; j < cols; j++)
        {
            printf("img[%3d][%3d]=", i, j);
            for (int k=0; k< depth; ++k)
            {
                printf(" %3d", arr[(i*cols + j)*depth + k]);
            }
            printf("\\n");
        }
    }
    """

    weave.inline(code, ['arr'])


def blitz_inline(arr):
    """Prints the given 3D array by using blitz converters which
    provides a scipy_base.numerix-like syntax for accessing the scipy_base.numerix data.

    Notice the following:
      1. '\\n' to escape generating a newline in the C++ code.
      2. rows, cols = Narr[0], Narr[1].
      3. Array access using arr(i, j, k).
      
    """
    
    code = """
    int rows = Narr[0];
    int cols = Narr[1];
    int depth = Narr[2];    
    for (int i=0; i < rows; i++)
    {
        for (int j=0; j < cols; j++)
        {
            printf("img[%3d][%3d]=", i, j);
            for (int k=0; k< depth; ++k)
            {
                printf(" %3d", arr(i, j, k));
            }
            printf("\\n");
        }
    }
    """

    weave.inline(code, ['arr'], type_converters=converters.blitz)


def main():
    arr = create_array()
    print "scipy_base.numerix:"    
    print arr

    print "Pure Inline:"
    pure_inline(arr)
    
    print "Blitz Inline:"
    blitz_inline(arr)
    

if __name__ == '__main__':
    main()