{{alias}}( N, x, stride, clbk[, thisArg] ) Calculates the range of a strided array via a callback function. The `N` and `stride` parameters determine which elements in `x` are accessed at runtime. Indexing is relative to the first index. To introduce an offset, use typed array views. If `N <= 0`, the function returns `x` unchanged. The callback function is provided four arguments: - value: array element - aidx: array index - sidx: strided index (offset + aidx*stride) - array: the input array The callback function should return a numeric value. If the callback function does not return any value (or equivalently, explicitly returns `undefined`), the value is ignored. Parameters ---------- N: integer Number of indexed elements. x: Array|TypedArray|Object Input array/collection. If provided an object, the object must be array- like (excluding strings and functions). stride: integer Index increment for `x`. clbk: Function Callback function. thisArg: any (optional) Execution context. Returns ------- out: number Range. Examples -------- // Standard Usage: > function accessor( v ) { return v * 2.0; }; > var x = [ -2.0, 1.0, 3.0, -5.0, 4.0, -1.0, -3.0 ]; > {{alias}}( x.length, x, 1, accessor ) 18.0 // Using `N` and `stride` parameters: > x = [ -2.0, 1.0, 3.0, -5.0, 4.0, -1.0, -3.0 ]; > var N = {{alias:@stdlib/math/base/special/floor}}( x.length / 2 ); > {{alias}}( N, x, 2, accessor ) 12.0 // Using view offsets: > var x0 = new {{alias:@stdlib/array/float64}}( [ 1.0, -2.0, 3.0, -4.0, 5.0, -6.0 ] ); > var x1 = new {{alias:@stdlib/array/float64}}( x0.buffer, x0.BYTES_PER_ELEMENT*1 ); > N = {{alias:@stdlib/math/base/special/floor}}( x0.length / 2 ); > {{alias}}( N, x1, 2, accessor ) 8.0 {{alias}}.ndarray( N, x, stride, offset, clbk[, thisArg] ) Calculates the range of a strided array via a callback function and using alternative indexing semantics. While typed array views mandate a view offset based on the underlying buffer, the `offset` parameter supports indexing semantics based on a starting index. Parameters ---------- N: integer Number of indexed elements. x: Array|TypedArray|Object Input array/collection. If provided an object, the object must be array- like (excluding strings and functions). stride: integer Index increment for `x`. offset: integer Starting index of `x`. clbk: Function Callback function. thisArg: any (optional) Execution context. Returns ------- out: number Range. Examples -------- // Standard Usage: > function accessor( v ) { return v * 2.0; }; > var x = [ -2.0, 1.0, 3.0, -5.0, 4.0, -1.0, -3.0 ]; > {{alias}}.ndarray( x.length, x, 1, 0, accessor ) 18.0 // Using an index offset: > x = [ 1.0, -2.0, 3.0, -4.0, 5.0, -6.0 ]; > var N = {{alias:@stdlib/math/base/special/floor}}( x.length / 2 ); > {{alias}}.ndarray( N, x, 2, 1, accessor ) 8.0 See Also --------