function StochasticProcess(svg, width, height, dx, dy, delta, timeout, sq, N) { function ScaledPosX(x) { return ((dx+x) * width / (2*dx)); } function ScaledPosY(y) { return ((dy+y) * height / (2*dy)); } function ScaledPosXInv(x) { return (x * (2*dx) / width) - dx; } function ScaledPosYInv(y) { return (y * (2*dy) / height) - dy; } function Inside(pos) { return (pos[0] >= -dx) && (pos[1] >= -dy) && (pos[0] < dx) && (pos[1] < dy); } function Wall(pos) { if (pos[0] >= dx) pos[0] = dx-1; if (pos[0] < -dx) pos[0] = -dx; if (pos[1] >= dy) pos[1] = dy-1; if (pos[1] < -dy) pos[1] = -dy; return pos; } var pos = []; for (var i = 0; i < N; ++i) { pos.push([0,0]); } var point = svg.selectAll("circle").data(pos) .enter().append("circle") .attr("r", 2) .attr("cx", d => ScaledPosX(d[0])) .attr("cy", d => ScaledPosY(d[1])); var process = null; function SetProcess(process_) { process = process_; } var func = null; function SetFunction(func_) { func = func_; var max_func = 0; for (var i = 0; i <= width/sq; ++i) { for (var j = 0; j <= height/sq; ++j) { max_func = Math.max(max_func,func([ScaledPosXInv(i*sq + sq/2), ScaledPosYInv(j*sq + sq/2)])); } } var values = new Array((1+ width/sq)*(1+ height/sq)); for (var j = 0, k = 0; j <= height/sq; ++j) { for (var i = 0; i <= width/sq; ++i, ++k) { values[k] = func([ScaledPosXInv(i*sq + sq/2), ScaledPosYInv(j*sq + sq/2)]) / max_func; } } var contours = d3.contours().size([1+ width/sq, 1+ height/sq]) .thresholds(d3.range(0, 100).map(p => p/100)); var color = d3.scaleLinear().domain([0,1.5]).range(["white", "blue"]); svg.selectAll("path") .data(contours(values)) .enter().append("path") .attr("d", d3.geoPath(d3.geoIdentity().scale(sq))) .attr("fill", function(d) { return color(d.value); }); svg.selectAll("circle").remove(); point = svg.selectAll("circle").data(pos) .enter().append("circle") .attr("r", 2) .attr("cx", d => ScaledPosX(d[0])) .attr("cy", d => ScaledPosY(d[1])); } // possible values: // "r" = reflect // "b" = remove if outside box // "n" = do nothing, i.e, keep all points and render if in box var reflect = "n"; function SetReflectBoundary(reflect_) { reflect = reflect_; } var line = false; function DrawLine(line_) { line = line_; } function Start() { function Move() { for (var i = 0; i < pos.length; ++i) { var newpos = process(pos[i]); if (line) { svg.append("line") .attr("x1", ScaledPosX(pos[i][0])) .attr("x2", ScaledPosX(newpos[0])) .attr("y1", ScaledPosY(pos[i][1])) .attr("y2", ScaledPosY(newpos[1])) .attr("stroke", "black"); } pos[i] = newpos; } if (reflect == "r") { for (var i = 0; i < pos.length; ++i) { pos[i] = Wall(pos[i]); } } else if (reflect == "b") { pos = pos.filter(Inside); } var ipos = pos.filter(Inside); point.data(ipos).enter().append("circle") .attr("r", 2) .attr("cx", d => ScaledPosX(d[0])) .attr("cy", d => ScaledPosY(d[1])); point.data(ipos).exit().remove(); point.data(ipos) .attr("cx", d => ScaledPosX(d[0])) .attr("cy", d => ScaledPosY(d[1])); if (pos.length > 0) { setTimeout(Move, timeout); } } Move(); } return { SetProcess: SetProcess, SetReflectBoundary: SetReflectBoundary, SetFunction: SetFunction, DrawLine: DrawLine, Start: Start, } }