Zip
Generate array tuples from input arrays.
Usage
var zip = require( '@stdlib/utils/zip' );
zip( arr1, arr2,...[, opts] )
Returns an array of arrays, where the ith element (tuple) in the returned array contains the ith elements of the input arrays.
var zipped = zip( [ 1, 2 ], [ 'a', 'b' ] );
// returns [ [ 1, 'a' ], [ 2, 'b' ] ]
By default, the returned array length is the length of the shortest input array.
var zipped = zip( [ 1, 2, 3 ], [ 'a', 'b' ] );
// returns [ [ 1, 'a' ], [ 2, 'b' ] ]
The function accepts an options object with optional properties:
- trunc:
booleanspecifying whether the returnedarrayshould truncatearrayslonger than the shortestarray. Default:true. - fill: fill value used for unequal length
arrays. Default:null. - arrays:
booleanspecifying whether, when provided a single inputarray, the function should interpret the argument as a list ofarraysto be zipped (i.e., behavior similar tozip.apply(null, arr)). Default:false.
To turn off truncation,
var opts = {
'trunc': false
};
var zipped = zip( [ 1, 2, 3 ], [ 'a', 'b' ], opts );
// returns [ [ 1, 'a' ], [ 2, 'b' ], [ 3, null ] ]
A fill value is included in each tuple for each array which does not have an element at the ith index. By default, the fill value is null. To specify a different fill value, set the fill option.
var opts = {
'trunc': false,
'fill': ''
};
var zipped = zip( [ 1, 2, 3 ], [ 'a', 'b' ], opts );
// returns [ [ 1, 'a' ], [ 2, 'b' ], [ 3, '' ] ]
If the function should interpret a single input array as an array of arrays to be zipped,
var arr = [ [ 1, 2 ], [ 'a', 'b' ] ];
// Default behavior:
var zipped = zip( arr );
// returns [ [ [ 1, 2 ] ], [ [ 'a', 'b' ] ] ]
// Array of arrays:
zipped = zip( arr, { 'arrays': true } );
// returns [ [ 1, 'a' ], [ 2, 'b' ] ]
Examples
var randu = require( '@stdlib/random/base/randu' );
var zip = require( '@stdlib/utils/zip' );
var x = [];
var y1 = [];
var y2 = [];
var y3 = [];
// Simulate some data...
var i;
for ( i = 0; i < 100; i++ ) {
x.push( Date.now() );
y1.push( randu() * 100 );
y2.push( randu() * 100 );
y3.push( randu() );
}
var zipped = zip( x, y1, y2, y3 );
console.log( zipped.join( '\n' ) );