var nanminBy = require( '@stdlib/stats/strided/nanmin-by' );

Computes the minimum value of a strided array via a callback function, ignoring NaN values.

function accessor( v ) {
    return v * 2.0;
}

var x = [ -2.0, 1.0, 3.0, -5.0, 4.0, NaN, 0.0, -1.0, -3.0, NaN ];

var v = nanminBy( x.length, x, 1, accessor );
// returns -10.0

The function has the following parameters:

• N: number of indexed elements.
• x: input Array, typed array, or an array-like object (excluding strings and functions).
• strideX: stride length.
• clbk: callback function.
• thisArg: execution context (optional).

The invoked callback is provided four arguments:

• value: array element.
• aidx: array index.
• sidx: strided index (offset + aidx*stride).
• array: input array/collection.

To set the callback execution context, provide a thisArg.

function accessor( v ) {
    this.count += 1;
    return v * 2.0;
}

var x = [ -2.0, 1.0, 3.0, -5.0, 4.0, NaN, 0.0, -1.0, -3.0, NaN ];

var context = {
    'count': 0
};

var v = nanminBy( x.length, x, 1, accessor, context );
// returns -10.0

var cnt = context.count;
// returns 10

The N and stride parameters determine which elements in the strided array are accessed at runtime. For example, to access every other element

function accessor( v ) {
    return v * 2.0;
}

var x = [ -2.0, 1.0, 3.0, -5.0, 4.0, 0.0, -1.0, -3.0, NaN, NaN ];

var v = nanminBy( 5, x, 2, accessor );
// returns -4.0

Note that indexing is relative to the first index. To introduce an offset, use typed array views.

var Float64Array = require( '@stdlib/array/float64' );

function accessor( v ) {
    return v * 2.0;
}

// Initial array...
var x0 = new Float64Array( [ 1.0, -2.0, 3.0, -4.0, 5.0, -6.0 ] );

// Create an offset view...
var x1 = new Float64Array( x0.buffer, x0.BYTES_PER_ELEMENT*1 ); // start at 2nd element

// Access every other element...
var v = nanminBy( 3, x1, 2, accessor );
// returns -12.0

Computes the minimum value of a strided array via a callback function, ignoring NaN values and using alternative indexing semantics.

function accessor( v ) {
    return v * 2.0;
}

var x = [ -2.0, 1.0, 3.0, -5.0, 4.0, NaN, 0.0, -1.0, -3.0, NaN ];

var v = nanminBy.ndarray( x.length, x, 1, 0, accessor );
// returns -10.0

The function has the following additional parameters:

• offsetX: starting index.

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 access only the last three elements of x

function accessor( v ) {
    return v * 2.0;
}

var x = [ 1.0, -2.0, 3.0, -4.0, 5.0, -6.0 ];

var v = nanminBy.ndarray( 3, x, 1, x.length-3, accessor );
// returns -12.0

• If N <= 0, both functions return NaN.
• A provided callback function should return a numeric value.
• If a provided callback function returns NaN, the value is ignored.
• If a provided callback function does not return any value (or equivalently, explicitly returns undefined), the value is ignored.
• Both functions support array-like objects having getter and setter accessors for array element access (e.g., @stdlib/array/base/accessor).
• When possible, prefer using dnanmin, snanmin, and/or nanmin, as, depending on the environment, these interfaces are likely to be significantly more performant.

• @stdlib/stats/strided/dnanmin: calculate the minimum value of a double-precision floating-point strided array, ignoring NaN values.
• @stdlib/stats/strided/min-by: calculate the minimum value of a strided array via a callback function.
• @stdlib/stats/strided/nanmax-by: calculate the maximum value of a strided array via a callback function, ignoring NaN values.
• @stdlib/stats/strided/nanmin: calculate the minimum value of a strided array, ignoring NaN values.
• @stdlib/stats/strided/snanmin: calculate the minimum value of a single-precision floating-point strided array, ignoring NaN values.