curve fitting and assorted fixes

lib/site/handlers.js

@@ -2356,6 +2356,64 @@ return {
       api.drawCurve(curve);
     }
   }
+};
+ }())
+  },
+  "curvefitting": {
+    handler: (function() { var fit = require('../../../lib/curve-fitter.js');
+
+return {
+  setup: function(api) {
+    this.api = api;
+    this.reset();
+  },
+
+  reset: function() {
+    this.points = [];
+    this.curveset = false;
+    let api = this.api;
+    if (api) {
+      api.setCurve(false);
+      api.reset();
+      api.redraw();
+    }
+  },
+
+  draw: function(api, curve) {
+    api.setPanelCount(1);
+    api.reset();
+    api.setColor('lightgrey');
+    api.drawGrid(10,10);
+
+    api.setColor('black');
+    if (!this.curveset && this.points.length > 2) {
+      let bestFitData = fit(this.points),
+          x = bestFitData.C.x,
+          y = bestFitData.C.y,
+          bpoints = [];
+      x.forEach((r,i) => {
+        bpoints.push({
+          x: r[0],
+          y: y[i][0]
+        });
+      });
+      curve = new api.Bezier(bpoints);
+      api.setCurve(curve);
+      this.curveset = true;
+    }
+
+    if (curve) {
+      api.drawCurve(curve);
+      api.drawSkeleton(curve);
+    }
+    api.drawPoints(this.points);
+  },
+
+  onClick: function(evt, api) {
+    this.curveset = false;
+    this.points.push({x: api.mx, y: api.my });
+    api.redraw();
+  }
 };
  }())
   },