src/utils/d3-labeler.js
var d3Labeler = function () {
var lab = [],
anc = [],
w = 1, // box width
h = 1, // box width
labeler = {};
var max_move = 5.0,
max_angle = 0.5,
acc = 0,
rej = 0;
// weights
var w_len = 0.2, // leader line length
w_inter = 1.0, // leader line intersenpm testction
w_lab2 = 30.0, // label-label overlap
w_lab_anc = 30.0, // label-anchor overlap
w_orient = 3.0; // orientation bias
// booleans for user defined functions
var user_energy = false;
var user_defined_energy;
var energy = function (index) {
// energy function, tailored for label placement
var m = lab.length,
ener = 0,
dx = lab[index].x - anc[index].x,
dy = anc[index].y - lab[index].y,
dist = Math.sqrt(dx * dx + dy * dy),
overlap = true;
// penalty for length of leader line
if (dist > 0) {
ener += dist * w_len;
}
// label orientation bias
dx /= dist;
dy /= dist;
if (dx > 0 && dy > 0) {
ener += 0 * w_orient;
} else if (dx < 0 && dy > 0) {
ener += 1 * w_orient;
} else if (dx < 0 && dy < 0) {
ener += 2 * w_orient;
} else {
ener += 3 * w_orient;
}
var x21 = lab[index].x,
y21 = lab[index].y - lab[index].height + 2.0,
x22 = lab[index].x + lab[index].width,
y22 = lab[index].y + 2.0;
var x11, x12, y11, y12, x_overlap, y_overlap, overlap_area;
for (var i = 0; i < m; i++) {
if (i != index) {
// penalty for intersection of leader lines
// eslint-disable-next-line @typescript-eslint/no-use-before-define
overlap = intersect(anc[index].x, lab[index].x, anc[i].x, lab[i].x,
anc[index].y, lab[index].y, anc[i].y, lab[i].y);
if (overlap) {
ener += w_inter;
}
// penalty for label-label overlap
x11 = lab[i].x;
y11 = lab[i].y - lab[i].height + 2.0;
x12 = lab[i].x + lab[i].width;
y12 = lab[i].y + 2.0;
x_overlap = Math.max(0, Math.min(x12, x22) - Math.max(x11, x21));
y_overlap = Math.max(0, Math.min(y12, y22) - Math.max(y11, y21));
overlap_area = x_overlap * y_overlap;
ener += (overlap_area * w_lab2);
}
// penalty for label-anchor overlap
x11 = anc[i].x - anc[i].r;
y11 = anc[i].y - anc[i].r;
x12 = anc[i].x + anc[i].r;
y12 = anc[i].y + anc[i].r;
x_overlap = Math.max(0, Math.min(x12, x22) - Math.max(x11, x21));
y_overlap = Math.max(0, Math.min(y12, y22) - Math.max(y11, y21));
overlap_area = x_overlap * y_overlap;
ener += (overlap_area * w_lab_anc);
}
return ener;
};
var mcmove = function (currT) {
// Monte Carlo translation move
// select a random label
var i = Math.floor(Math.random() * lab.length);
// save old coordinates
var x_old = lab[i].x;
var y_old = lab[i].y;
// old energy
var old_energy;
if (user_energy) {
old_energy = user_defined_energy(i, lab, anc);
} else {
old_energy = energy(i);
}
// random translation
lab[i].x += (Math.random() - 0.5) * max_move;
lab[i].y += (Math.random() - 0.5) * max_move;
// hard wall boundaries
if (lab[i].x > w) {
lab[i].x = x_old;
}
if (lab[i].x < 0) {
lab[i].x = x_old;
}
if (lab[i].y > h) {
lab[i].y = y_old;
}
if (lab[i].y < 0) {
lab[i].y = y_old;
}
// new energy
var new_energy;
if (user_energy) {
new_energy = user_defined_energy(i, lab, anc);
} else {
new_energy = energy(i);
}
// delta E
var delta_energy = new_energy - old_energy;
if (Math.random() < Math.exp(-delta_energy / currT)) {
acc += 1;
} else {
// move back to old coordinates
lab[i].x = x_old;
lab[i].y = y_old;
rej += 1;
}
};
var mcrotate = function (currT) {
// Monte Carlo rotation move
// select a random label
var i = Math.floor(Math.random() * lab.length);
// save old coordinates
var x_old = lab[i].x;
var y_old = lab[i].y;
// old energy
var old_energy;
if (user_energy) {
old_energy = user_defined_energy(i, lab, anc);
} else {
old_energy = energy(i);
}
// random angle
var angle = (Math.random() - 0.5) * max_angle;
var s = Math.sin(angle);
var c = Math.cos(angle);
// translate label (relative to anchor at origin):
lab[i].x -= anc[i].x;
lab[i].y -= anc[i].y;
// rotate label
var x_new = lab[i].x * c - lab[i].y * s,
y_new = lab[i].x * s + lab[i].y * c;
// translate label back
lab[i].x = x_new + anc[i].x;
lab[i].y = y_new + anc[i].y;
// hard wall boundaries
if (lab[i].x > w) {
lab[i].x = x_old;
}
if (lab[i].x < 0) {
lab[i].x = x_old;
}
if (lab[i].y > h) {
lab[i].y = y_old;
}
if (lab[i].y < 0) {
lab[i].y = y_old;
}
// new energy
var new_energy;
if (user_energy) {
new_energy = user_defined_energy(i, lab, anc);
} else {
new_energy = energy(i);
}
// delta E
var delta_energy = new_energy - old_energy;
if (Math.random() < Math.exp(-delta_energy / currT)) {
acc += 1;
} else {
// move back to old coordinates
lab[i].x = x_old;
lab[i].y = y_old;
rej += 1;
}
};
var intersect = function (x1, x2, x3, x4, y1, y2, y3, y4) {
// returns true if two lines intersect, else false
// from http://paulbourke.net/geometry/lineline2d/
var mua, mub;
var denom, numera, numerb;
denom = (y4 - y3) * (x2 - x1) - (x4 - x3) * (y2 - y1);
numera = (x4 - x3) * (y1 - y3) - (y4 - y3) * (x1 - x3);
numerb = (x2 - x1) * (y1 - y3) - (y2 - y1) * (x1 - x3);
/* Is the intersection along the the segments */
mua = numera / denom;
mub = numerb / denom;
if (!(mua < 0 || mua > 1 || mub < 0 || mub > 1)) {
return true;
}
return false;
};
var cooling_schedule = function (currT, initialT, nsweeps) {
// linear cooling
return (currT - (initialT / nsweeps));
};
labeler.start = function (nsweeps) {
// main simulated annealing function
var m = lab.length,
currT = 1.0,
initialT = 1.0;
for (var i = 0; i < nsweeps; i++) {
for (var j = 0; j < m; j++) {
if (Math.random() < 0.5) {
mcmove(currT);
} else {
mcrotate(currT);
}
}
currT = cooling_schedule(currT, initialT, nsweeps);
}
};
labeler.width = function (x) {
// users insert graph width
if (!arguments.length) {
return w;
}
w = x;
return labeler;
};
labeler.height = function (x) {
// users insert graph height
if (!arguments.length) {
return h;
}
h = x;
return labeler;
};
labeler.label = function (x) {
// users insert label positions
if (!arguments.length) {
return lab;
}
lab = x;
return labeler;
};
labeler.anchor = function (x) {
// users insert anchor positions
if (!arguments.length) {
return anc;
}
anc = x;
return labeler;
};
labeler.alt_energy = function (x) {
// user defined energy
if (!arguments.length) {
return energy;
}
user_defined_energy = x;
user_energy = true;
return labeler;
};
labeler.alt_schedule = function () {
// user defined cooling_schedule
if (!arguments.length) {
return cooling_schedule;
}
return labeler;
};
return labeler;
};
export {d3Labeler};