/***************************************************************************** * reduce.cpp     Blitz++ array reduction example * * This example illustrates the array reduction functions provided by * Blitz++.  These functions reduce an N dimensional array (or array * expression) to an N-1 dimensional array expression by summing, taking * the mean, etc.  These array reductions are currently provided: sum, * mean, min, max, minIndex, maxIndex, product, count, any and all. *****************************************************************************/#include <blitz/array.h>BZ_USING_NAMESPACE(blitz)int main(){    Array<int, 2> A(4,4);    A = 3,  1,  2,  4,               8, -1, -5,  3,               0,  9, -1,  4,        1,  3,  1,  2;    cout << "A = " << A << endl;    /*     * Reduce the array A to a one-dimensional array, by summing/taking     * the mean/etc. of each row.     */    Array<int, 1> z(4);    Array<float, 1> z2(4);    secondIndex j;    z = sum(A, j);    cout << "sum(A,j) = " << endl << z << endl;    z2 = mean(A, j);    cout << "mean(A,j) = " << endl << z2 << endl;    z = min(A, j);    cout << "min(A,j) = " << endl << z << endl;    z = minIndex(A, j);    cout << "minIndex(A, j) = " << endl << z << endl;    z = max(A, j);    cout << "max(A, j) = " << endl << z << endl;    z = maxIndex(A, j);    cout << "maxIndex(A, j) = " << endl << z << endl;    z = first((A < 0), j);    cout << "first((A < 0), j) = " << endl << z << endl;    z = product(A, j);    cout << "product(A, j) = " << endl << z << endl;    z = count( (A > 0), j);    cout << "count((A > 0), j) = " << endl << z << endl;    z = any((abs(A) > 4), j);    cout << "any((abs(A) > 4), j) = " << endl << z << endl;    z = all(A > 0, j);    cout << "all(A > 0, j) = " << endl << z << endl;    return 0;}/* * Output */#if 0A = 4 x 4         3         1         2         4         8        -1        -5         3         0         9        -1         4         1         3         1         2sum(A,j) =[         10         5        12         7 ]mean(A,j) =[        2.5      1.25         3      1.75 ]min(A,j) =[          1        -5        -1         1 ]minIndex(A, j) =[          1         2         2         0 ]max(A, j) =[          4         8         9         3 ]maxIndex(A, j) =[          3         0         1         1 ]product(A, j) =[         24       120         0         6 ]count((A > 0), j) =[          4         2         2         4 ]any((abs(A) > 4), j) =[          0         1         1         0 ]all(A > 0, j) =[          1         0         0         1 ]#endif