code: function isnan( arr ) {
  	if ( !Array.isArray( arr ) ) {
  		throw new TypeError( 'isnan()::invalid input argument. Must provide an array.' );
  	}
  	var len = arr.length,
  		out = new Array( len ),
  		val;
  
  	for ( var i = 0; i < len; i++ ) {
  		out[ i ] = 0;
  		val = arr[ i ];
  		if ( typeof val !== 'number' || val !== val ) {
  			out[ i ] = 1;
  		}
  	}
  	return out;
  }
docs: ISNAN // 
  FUNCTION: isnan( arr )
  Computes for each array element whether an element is NaN.
  
  @param {Array} arr - input array
  @param {Array} array of 1s and 0s indicating if an element is NaN