function createCubehelix (steps, opts) {
	var data = [];

	for (var i = 0; i < steps; i++ ){
		data.push(cubehelix.rgb(i/steps, opts).map((v) => v/255));
	}

	return data;
}
function createCubehelix (steps, opts) {
	var data = [];

	for (var i = 0; i < steps; i++ ){
		data.push(cubehelix.rgb(i/steps, opts).map((v) => v/255));
	}

	return data;
}
function createCubehelix ( steps , opts ) { var data = [ ] ; for ( var i = 0 ; i < steps ; i ++ ) { data . push ( cubehelix . rgb ( i / steps , opts ) . map ( ( v ) => v / 255 ) ) ; } return data ; }
create colormap by rotating cubehelix
create colormap by rotating cubehelix