std

Computes the standard deviation of a slice.

auto std(S slice, bool isPopulation)
template std(sumTemplateArgs...)
nothrow @nogc deprecated pure nothrow @nogc
auto
std
(
S
)
(
S slice
,
bool isPopulation = true
)
if (
isSlice!S
)
auto std(S slice, Seed seed, bool isPopulation)

Members

Functions

std deprecated auto std(S slice, bool isPopulation)
std deprecated auto std(S slice, Seed seed, bool isPopulation): Undocumented in source. Be warned that the author may not have intended to support it.

Parameters

sumTemplateArgs: template arguments to pass to mir.math.sum (to compute the mean & variance of the slice)

Examples

Standard deviation of vector

import std.math : approxEqual;
import mir.ndslice.slice : sliced;
import mir.math.common : sqrt;

static immutable x = [0.0, 1.0, 1.5, 2.0, 3.5, 4.25,
                      2.0, 7.5, 5.0, 1.0, 1.5, 0.0];

assert(approxEqual(x.sliced.std, sqrt(54.76563 / 12)));
assert(approxEqual(x.sliced.std(false), sqrt(54.76563 / 11)));
assert(approxEqual(x.sliced.std(true), sqrt(54.76563 / 12)));

Standard deviation of matrix

import mir.ndslice.slice : sliced;
import std.math : approxEqual;
import mir.math.common : sqrt;

static immutable x = [0.0, 1.0, 1.5, 2.0, 3.5, 4.25,
                      2.0, 7.5, 5.0, 1.0, 1.5, 0.0];

assert(approxEqual(x.sliced(2, 6).std, sqrt(54.76563 / 12)));
assert(approxEqual(x.sliced(2, 6).std(false), sqrt(54.76563 / 11)));
assert(approxEqual(x.sliced(2, 6).std(true), sqrt(54.76563 / 12)));

Row standard deviation of matrix

import mir.ndslice.slice : sliced;
import mir.ndslice.topology : alongDim, byDim, map;
import mir.math.common : sqrt;
import numir : approxEqual;

static immutable x = [0.0, 1.0, 1.5, 2.0, 3.5, 4.25,
                      2.0, 7.5, 5.0, 1.0, 1.5, 0.0];
static immutable y = [sqrt(2.092014), sqrt(6.722222)];

// Use byDim or alongDim or alongDim with map to compute variance of row/column.
assert(approxEqual(x.sliced(2, 6).byDim!0.map!(a => a.std(true)), y.sliced));
assert(approxEqual(x.sliced(2, 6).alongDim!1.map!(a => a.std(true)), y.sliced));

std

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Parameters

Examples

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