d3.parcoords.js
function paths(data, ctx) {
        ctx.clearRect(-1, -1, w() + 2, h() + 2);
        ctx.beginPath();
        data.forEach(function(d) {
            if ((__.bundleDimension !== null && __.bundlingStrength > 0) || __.smoothness > 0) {
                single_curve(d, ctx);
            } else {
                single_path(d, ctx);
            }
        });
        ctx.stroke();
    }
function paths(data, ctx) {
        ctx.clearRect(-1, -1, w() + 2, h() + 2);
        ctx.beginPath();
        data.forEach(function(d) {
            if ((__.bundleDimension !== null && __.bundlingStrength > 0) || __.smoothness > 0) {
                single_curve(d, ctx);
            } else {
                single_path(d, ctx);
            }
        });
        ctx.stroke();
    }
draw many polylines of the same color