Numerical integration: Difference between revisions

Line 893:

template integrate(alias method) {

double integrate(F, Float)(F f, in Float a,

double integrate(F, Float)(in F f, in Float a,

in Float b, in int steps) {

double s = 0.0;

immutable double h = (b - a) / steps;

foreach (i; 0 .. steps)

s += method(f, a + h*i, h);

s += method(f, a + h * i, h);

return h * s;

}

Line 910:

double rectangularMiddle(F, Float)(in F f, in Float x, in Float h)

pure nothrow {

return f(x + h/2);

return f(x + h / 2);

}

Line 925:

double simpson(F, Float)(in F f, in Float x, in Float h)

pure nothrow {

return (f(x) + 4*f(x + h/2) + f(x + h)) / 6;

return (f(x) + 4 * f(x + h / 2) + f(x + h)) / 6;

}

Line 988:

immutable Float h = (b - a) / steps;

foreach (i; 0 .. steps)

s += method!(f, Float)(a + h*i, h);

s += method!(f, Float)(a + h * i, h);

return h * s;

}

Line 1,001:

double rectangularMiddle(alias f, Float)(in Float x, in Float h)

pure nothrow {

return f(x + h/2);

return f(x + h / 2);

}

Line 1,016:

double simpson(alias f, Float)(in Float x, in Float h)

pure nothrow {

return (f(x) + 4*f(x + h/2) + f(x + h)) / 6;

return (f(x) + 4 * f(x + h / 2) + f(x + h)) / 6;

}

⚫

double f1(in double x) pure nothrow { return x ^^ 3; }

⚫

double f2(in double x) pure nothrow{ return 1 / x; }

⚫

double f3(in double x) pure nothrow{ return x; }

⚫

alias TypeTuple!(f1, f2, f3, f3) funcs;

void main() {

⚫

static double f1(in double x) pure nothrow { return x ^^ 3; }

⚫

static double f2(in double x) pure nothrow { return 1 / x; }

⚫

static double f3(in double x) pure nothrow { return x; }

⚫

alias TypeTuple!(f1, f2, f3, f3) funcs;

alias TypeTuple!("rectangular left: ",

"rectangular middle: ",