mylines = {
let myline = positives.filter(d => d.y == lines[l]);
let ybase = d3.min(myline, d => d.y);
let myline2 = myline
.map(d => ({
x: d.x,
y: d.y - k * d.z
}))
.sort(function(x, y) {
return d3.ascending(x.x, y.x);
});
let a = { x: xmin, y: ybase };
let b = { x: xmax, y: ybase };
myline2.unshift(a);
myline2.push(b);
return myline2;
}