Re: Fast multidimensional Arrays

[rikki cattermole via Digitalmars-d-learn]

On 30/08/2016 1:50 AM, Steinhagelvoll wrote:

It seems that the ini doesn't work properly. Every value seems to be nan.

ini(A);
ini(B);
ini(C);
writeln(A[0][0]);
writeln(C[3][9]);

nan
nan

My bad, fixed:

double[1000][] A, B, C;

void main() {
        A = new double[1000][1000];
        B = new double[1000][1000];
        C = new double[1000][1000];

        import std.conv : to;
        import std.datetime;
        import std.stdio : writeln;

        ini(A);
        ini(B);
        ini(C);

        auto r = benchmark!run_test(10000);
        auto res = to!Duration(r[0]);
        writeln(res);
}

void run_test() {
        MatMul(A, B, C);
}

void ini(T)(T mtx) {
        foreach(ref v; mtx) {
                v = 3.4;
        }

        foreach(i, v; mtx) {
                foreach(j, ref vv; v) {
                        vv += (i * j) + (0.6 * j);
                }
        }
}

void MatMul(T)(T A, T B, T C) {
        foreach(cv; C) {
                cv = 0f;
        }

        foreach(i, cv; C) {
                foreach(j, av; A[i]) {
                        auto bv = B[j];
                        foreach(k, cvv; cv) {
                                cvv += av * bv[k];
                        }
                }
        }

}