docs: function ekurtosis( arr, path, sep ) {
  	var len = arr.length,
  		opts = {},
  		dget,
  		dset,
  		v, i;
  	if ( arguments.length > 2 ) {
  		opts.sep = sep;
  	}
  	if ( len ) {
  		dget = deepGet( path, opts );
  		dset = deepSet( path, opts );
  		for ( i = 0; i < len; i++ ) {
  			v = dget( arr[ i ] );
  			if ( typeof v === 'number' ) {
  				dset( arr[i], EKURTOSIS ( v ) );
  			} else {
  				dset( arr[i], NaN );
  			}
  		}
  	}
  	return arr;
  }