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Calculate the minimum value of a single-precision floating-point strided array according to a mask, ignoring
NaN
values.
import snanmskmin from 'https://cdn.jsdelivr.net/gh/stdlib-js/stats-base-snanmskmin@esm/index.mjs';
Computes the minimum value of a single-precision floating-point strided array x
according to a mask
, ignoring NaN
values.
import Float32Array from 'https://cdn.jsdelivr.net/gh/stdlib-js/array-float32@esm/index.mjs';
import Uint8Array from 'https://cdn.jsdelivr.net/gh/stdlib-js/array-uint8@esm/index.mjs';
var x = new Float32Array( [ 1.0, -2.0, -4.0, 2.0, NaN ] );
var mask = new Uint8Array( [ 0, 0, 1, 0, 0 ] );
var v = snanmskmin( x.length, x, 1, mask, 1 );
// returns -2.0
The function has the following parameters:
- N: number of indexed elements.
- x: input
Float32Array
. - strideX: index increment for
x
. - mask: mask
Uint8Array
. If amask
array element is0
, the corresponding element inx
is considered valid and included in computation. If amask
array element is1
, the corresponding element inx
is considered invalid/missing and excluded from computation. - strideMask: index increment for
mask
.
The N
and stride
parameters determine which elements are accessed at runtime. For example, to compute the minimum value of every other element in x
,
import Float32Array from 'https://cdn.jsdelivr.net/gh/stdlib-js/array-float32@esm/index.mjs';
import Uint8Array from 'https://cdn.jsdelivr.net/gh/stdlib-js/array-uint8@esm/index.mjs';
import floor from 'https://cdn.jsdelivr.net/gh/stdlib-js/math-base-special-floor@esm/index.mjs';
var x = new Float32Array( [ 1.0, 2.0, 7.0, -2.0, -4.0, 3.0, -5.0, -6.0 ] );
var mask = new Uint8Array( [ 0, 0, 0, 0, 0, 0, 1, 1 ] );
var N = floor( x.length / 2 );
var v = snanmskmin( N, x, 2, mask, 2 );
// returns -4.0
Note that indexing is relative to the first index. To introduce offsets, use typed array
views.
import Float32Array from 'https://cdn.jsdelivr.net/gh/stdlib-js/array-float32@esm/index.mjs';
import Uint8Array from 'https://cdn.jsdelivr.net/gh/stdlib-js/array-uint8@esm/index.mjs';
import floor from 'https://cdn.jsdelivr.net/gh/stdlib-js/math-base-special-floor@esm/index.mjs';
var x0 = new Float32Array( [ 2.0, 1.0, -2.0, -2.0, 3.0, 4.0, -5.0, -6.0 ] );
var x1 = new Float32Array( x0.buffer, x0.BYTES_PER_ELEMENT*1 ); // start at 2nd element
var mask0 = new Uint8Array( [ 0, 0, 0, 0, 0, 0, 1, 1 ] );
var mask1 = new Uint8Array( mask0.buffer, mask0.BYTES_PER_ELEMENT*1 ); // start at 2nd element
var N = floor( x0.length / 2 );
var v = snanmskmin( N, x1, 2, mask1, 2 );
// returns -2.0
Computes the minimum value of a single-precision floating-point strided array according to a mask
, ignoring NaN
values and using alternative indexing semantics.
import Float32Array from 'https://cdn.jsdelivr.net/gh/stdlib-js/array-float32@esm/index.mjs';
import Uint8Array from 'https://cdn.jsdelivr.net/gh/stdlib-js/array-uint8@esm/index.mjs';
var x = new Float32Array( [ 1.0, -2.0, -4.0, 2.0, NaN ] );
var mask = new Uint8Array( [ 0, 0, 1, 0, 0 ] );
var v = snanmskmin.ndarray( x.length, x, 1, 0, mask, 1, 0 );
// returns -2.0
The function has the following additional parameters:
- offsetX: starting index for
x
. - offsetMask: starting index for
mask
.
While typed array
views mandate a view offset based on the underlying buffer
, the offset
parameter supports indexing semantics based on a starting index. For example, to calculate the minimum value for every other value in x
starting from the second value
import Float32Array from 'https://cdn.jsdelivr.net/gh/stdlib-js/array-float32@esm/index.mjs';
import Uint8Array from 'https://cdn.jsdelivr.net/gh/stdlib-js/array-uint8@esm/index.mjs';
import floor from 'https://cdn.jsdelivr.net/gh/stdlib-js/math-base-special-floor@esm/index.mjs';
var x = new Float32Array( [ 2.0, 1.0, -2.0, -2.0, 3.0, 4.0, -5.0, -6.0 ] );
var mask = new Uint8Array( [ 0, 0, 0, 0, 0, 0, 1, 1 ] );
var N = floor( x.length / 2 );
var v = snanmskmin.ndarray( N, x, 2, 1, mask, 2, 1 );
// returns -2.0
- If
N <= 0
, both functions returnNaN
.
<!DOCTYPE html>
<html lang="en">
<body>
<script type="module">
import randu from 'https://cdn.jsdelivr.net/gh/stdlib-js/random-base-randu@esm/index.mjs';
import round from 'https://cdn.jsdelivr.net/gh/stdlib-js/math-base-special-round@esm/index.mjs';
import Float32Array from 'https://cdn.jsdelivr.net/gh/stdlib-js/array-float32@esm/index.mjs';
import Uint8Array from 'https://cdn.jsdelivr.net/gh/stdlib-js/array-uint8@esm/index.mjs';
import snanmskmin from 'https://cdn.jsdelivr.net/gh/stdlib-js/stats-base-snanmskmin@esm/index.mjs';
var mask;
var x;
var i;
x = new Float32Array( 10 );
mask = new Uint8Array( x.length );
for ( i = 0; i < x.length; i++ ) {
if ( randu() < 0.2 ) {
mask[ i ] = 1;
} else {
mask[ i ] = 0;
}
if ( randu() < 0.1 ) {
x[ i ] = NaN;
} else {
x[ i ] = round( (randu()*100.0) - 50.0 );
}
}
console.log( x );
console.log( mask );
var v = snanmskmin( x.length, x, 1, mask, 1 );
console.log( v );
</script>
</body>
</html>
@stdlib/stats-base/dnanmskmin
: calculate the minimum value of a double-precision floating-point strided array according to a mask, ignoring NaN values.@stdlib/stats-base/nanmskmin
: calculate the minimum value of a strided array according to a mask, ignoring NaN values.@stdlib/stats-base/smskmin
: calculate the minimum value of a single-precision floating-point strided array according to a mask.@stdlib/stats-base/snanmin
: calculate the minimum value of a single-precision floating-point strided array, ignoring NaN values.@stdlib/stats-base/snanmskmax
: calculate the maximum value of a single-precision floating-point strided array according to a mask, ignoring NaN values.
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