improve polar setConvert

- introduce 'g'eomtric coordinate system, that handles
  angular rotation / directrion and radial range shifts
- add 't'icks coord system for angular axes tick vals
- add setGeometry (which sets the c2g converters)
- make 'c' linear theta coordinates be in radians,
  eliminating trace.thetaunit deps after 'calc'

Author: etpinard

Diff for: src/lib/angles.js

@@ -27,3 +27,8 @@ exports.wrap180 = function(deg) {
     if(Math.abs(deg) > 180) deg -= Math.round(deg / 360) * 360;
     return deg;
 };
+
+exports.isFullCircle = function(sector) {
+    var arc = Math.abs(sector[1] - sector[0]);
+    return arc === 360;
+};

Diff for: src/lib/index.js

@@ -87,6 +87,7 @@ lib.deg2rad = anglesModule.deg2rad;
 lib.rad2deg = anglesModule.rad2deg;
 lib.wrap360 = anglesModule.wrap360;
 lib.wrap180 = anglesModule.wrap180;
+lib.isFullCircle = anglesModule.isFullCircle;
 
 var geom2dModule = require('./geometry2d');
 lib.segmentsIntersect = geom2dModule.segmentsIntersect;

Diff for: src/plots/polar/helpers.js

@@ -19,10 +19,9 @@ var handleTickLabelDefaults = require('../cartesian/tick_label_defaults');
 var handleCategoryOrderDefaults = require('../cartesian/category_order_defaults');
 var handleLineGridDefaults = require('../cartesian/line_grid_defaults');
 var autoType = require('../cartesian/axis_autotype');
-var setConvert = require('../cartesian/set_convert');
 
-var setConvertAngular = require('./helpers').setConvertAngular;
 var layoutAttributes = require('./layout_attributes');
+var setConvert = require('./set_convert');
 var constants = require('./constants');
 var axisNames = constants.axisNames;
 
@@ -66,7 +65,7 @@ function handleDefaults(contIn, contOut, coerce, opts) {
         });
 
         var visible = coerceAxis('visible');
-        setConvert(axOut, layoutOut);
+        setConvert(axOut, contOut, layoutOut);
 
         var dfltColor;
         var dfltFontColor;
@@ -140,8 +139,6 @@ function handleDefaults(contIn, contOut, coerce, opts) {
 
                 var direction = coerceAxis('direction');
                 coerceAxis('rotation', {counterclockwise: 0, clockwise: 90}[direction]);
-
-                setConvertAngular(axOut);
                 break;
         }