Better polar setConvert + a few misc polar touch ups

src/plots/polar/layout_defaults.js

@@ -198,7 +198,7 @@ function handleAxisTypeDefaults(axIn, axOut, coerce, subplotData, dataAttr) {
             }
         }
 
-        if(trace) {
+        if(trace && trace[dataAttr]) {
             axOut.type = autoType(trace[dataAttr], 'gregorian');
         }
 

src/plots/polar/set_convert.js

@@ -122,7 +122,18 @@ function setConvertAngular(ax, polarLayout) {
             for(i = 0; i < len; i++) {
                 arrayOut[i] = _d2c(arrayIn[i]);
             }
+        } else {
+            var coord0 = coord + '0';
+            var dcoord = 'd' + coord;
+            var v0 = (coord0 in trace) ? _d2c(trace[coord0]) : 0;
+            var dv = (trace[dcoord]) ? _d2c(trace[dcoord]) : (ax.period || 2 * Math.PI) / len;
+
+            arrayOut = new Array(len);
+            for(i = 0; i < len; i++) {
+                arrayOut[i] = v0 + i * dv;
+            }
         }
+
         return arrayOut;
     };
 

src/traces/scatterpolar/attributes.js

@@ -28,6 +28,49 @@ module.exports = {
         description: 'Sets the angular coordinates'
     },
 
+    r0: {
+        valType: 'any',
+        dflt: 0,
+        role: 'info',
+        editType: 'calc+clearAxisTypes',
+        description: [
+            'Alternate to `r`.',
+            'Builds a linear space of r coordinates.',
+            'Use with `dr`',
+            'where `r0` is the starting coordinate and `dr` the step.'
+        ].join(' ')
+    },
+    dr: {
+        valType: 'number',
+        dflt: 1,
+        role: 'info',
+        editType: 'calc',
+        description: 'Sets the r coordinate step.'
+    },
+
+    theta0: {
+        valType: 'any',
+        dflt: 0,
+        role: 'info',
+        editType: 'calc+clearAxisTypes',
+        description: [
+            'Alternate to `theta`.',
+            'Builds a linear space of theta coordinates.',
+            'Use with `dtheta`',
+            'where `theta0` is the starting coordinate and `dtheta` the step.'
+        ].join(' ')
+    },
+    dtheta: {
+        valType: 'number',
+        role: 'info',
+        editType: 'calc',
+        description: [
+            'Sets the theta coordinate step.',
+            'By default, the `dtheta` step equals the subplot\'s period divided',
+            'by the length of the `r` coordinates.'
+        ].join(' ')
+    },
+
     thetaunit: {
         valType: 'enumerated',
         values: ['radians', 'degrees', 'gradians'],

src/traces/scatterpolar/defaults.js

@@ -20,22 +20,17 @@ var PTS_LINESONLY = require('../scatter/constants').PTS_LINESONLY;
 
 var attributes = require('./attributes');
 
-module.exports = function supplyDefaults(traceIn, traceOut, defaultColor, layout) {
+function supplyDefaults(traceIn, traceOut, defaultColor, layout) {
     function coerce(attr, dflt) {
         return Lib.coerce(traceIn, traceOut, attributes, attr, dflt);
     }
 
-    var r = coerce('r');
-    var theta = coerce('theta');
-    var len = (r && theta) ? Math.min(r.length, theta.length) : 0;
-
+    var len = handleRThetaDefaults(traceIn, traceOut, layout, coerce);
     if(!len) {
         traceOut.visible = false;
         return;
     }
 
-    traceOut._length = len;
-
     coerce('thetaunit');
     coerce('mode', len < PTS_LINESONLY ? 'lines+markers' : 'lines');
     coerce('text');
@@ -76,4 +71,33 @@ module.exports = function supplyDefaults(traceIn, traceOut, defaultColor, layout
     coerce('hoveron', dfltHoverOn.join('+') || 'points');
 
     Lib.coerceSelectionMarkerOpacity(traceOut, coerce);
+}
+
+function handleRThetaDefaults(traceIn, traceOut, layout, coerce) {
+    var r = coerce('r');
+    var theta = coerce('theta');
+    var len;
+
+    if(r) {
+        if(theta) {
+            len = Math.min(r.length, theta.length);
+        } else {
+            len = r.length;
+            coerce('theta0');
+            coerce('dtheta');
+        }
+    } else {
+        if(!theta) return 0;
+        len = traceOut.theta.length;
+        coerce('r0');
+        coerce('dr');
+    }
+
+    traceOut._length = len;
+    return len;
+}
+
+module.exports = {
+    handleRThetaDefaults: handleRThetaDefaults,
+    supplyDefaults: supplyDefaults
 };

src/traces/scatterpolar/index.js

@@ -15,7 +15,7 @@ module.exports = {
     categories: ['polar', 'symbols', 'showLegend', 'scatter-like'],
 
     attributes: require('./attributes'),
-    supplyDefaults: require('./defaults'),
+    supplyDefaults: require('./defaults').supplyDefaults,
     colorbar: require('../scatter/marker_colorbar'),
     calc: require('./calc'),
     plot: require('./plot'),

src/traces/scatterpolargl/attributes.js

@@ -15,6 +15,10 @@ module.exports = {
     mode: scatterPolarAttrs.mode,
     r: scatterPolarAttrs.r,
     theta: scatterPolarAttrs.theta,
+    r0: scatterPolarAttrs.r0,
+    dr: scatterPolarAttrs.dr,
+    theta0: scatterPolarAttrs.theta0,
+    dtheta: scatterPolarAttrs.dtheta,
     thetaunit: scatterPolarAttrs.thetaunit,
 
     text: scatterPolarAttrs.text,

src/traces/scatterpolargl/defaults.js

@@ -11,6 +11,7 @@
 var Lib = require('../../lib');
 
 var subTypes = require('../scatter/subtypes');
+var handleRThetaDefaults = require('../scatterpolar/defaults').handleRThetaDefaults;
 var handleMarkerDefaults = require('../scatter/marker_defaults');
 var handleLineDefaults = require('../scatter/line_defaults');
 var handleFillColorDefaults = require('../scatter/fillcolor_defaults');
@@ -23,17 +24,12 @@ module.exports = function supplyDefaults(traceIn, traceOut, defaultColor, layout
         return Lib.coerce(traceIn, traceOut, attributes, attr, dflt);
     }
 
-    var r = coerce('r');
-    var theta = coerce('theta');
-    var len = (r && theta) ? Math.min(r.length, theta.length) : 0;
-
+    var len = handleRThetaDefaults(traceIn, traceOut, layout, coerce);
     if(!len) {
         traceOut.visible = false;
         return;
     }
 
-    traceOut._length = len;
-
     coerce('thetaunit');
     coerce('mode', len < PTS_LINESONLY ? 'lines+markers' : 'lines');
     coerce('text');

test/image/mocks/polar_r0dr-theta0dtheta.json

@@ -0,0 +1,77 @@
+{
+  "data": [{
+    "type": "scatterpolar",
+    "name": "missing θ",
+    "r": [1, 2, 3]
+  }, {
+    "type": "scatterpolar",
+    "name": "missing r",
+    "theta": [0, -90, -220]
+  }, {
+    "type": "scatterpolar",
+    "name": "set r0/dr",
+    "r0": 5,
+    "dr": -1,
+    "theta": [0, -90, -190]
+  }, {
+    "type": "scatterpolar",
+    "name": "set θ<sub>0</sub>/dθ",
+    "r": [1, 2, 3],
+    "theta0": 1,
+    "dtheta": 2,
+    "thetaunit": "radians"
+  },
+
+  {
+    "type": "scatterpolargl",
+    "name": "[gl] missing θ",
+    "subplot": "polar2",
+    "marker": {"color": "#1f77b4"},
+    "r": [1, 2, 3]
+  }, {
+    "type": "scatterpolargl",
+    "name": "[gl] missing r",
+    "subplot": "polar2",
+    "marker": {"color": "#ff7f0e"},
+    "theta": [0, -90, -220]
+  }, {
+    "type": "scatterpolargl",
+    "name": "[gl] set r0/dr",
+    "subplot": "polar2",
+    "marker": {"color": "#2ca02c"},
+    "r0": 5,
+    "dr": -1,
+    "theta": [0, -90, -190]
+  }, {
+    "type": "scatterpolargl",
+    "name": "[gl] set θ<sub>0</sub>/dθ",
+    "subplot": "polar2",
+    "marker": {"color": "#d62728"},
+    "r": [1, 2, 3],
+    "theta0": 1,
+    "dtheta": 2,
+    "thetaunit": "radians"
+  }],
+  "layout": {
+    "width": 500,
+    "height": 800,
+    "margin": {"l": 200, "t": 20, "b": 20},
+    "legend": {
+      "x": -0.2,
+      "xanchor": "right",
+      "y": 0.5
+    },
+    "polar": {
+      "domain": {
+        "x": [0, 1],
+        "y": [0.5, 1]
+      }
+    },
+    "polar2": {
+      "domain": {
+        "x": [0, 1],
+        "y": [0, 0.5]
+      }
+    }
+  }
+}

test/jasmine/tests/scatterpolar_test.js

@@ -28,6 +28,10 @@ describe('Test scatterpolar trace defaults:', function() {
         expect(traceOut.r).toEqual([1, 2, 3, 4, 5]);
         expect(traceOut.theta).toEqual([1, 2, 3]);
         expect(traceOut._length).toBe(3);
+        expect(traceOut.r0).toBeUndefined();
+        expect(traceOut.dr).toBeUndefined();
+        expect(traceOut.theta0).toBeUndefined();
+        expect(traceOut.dtheta).toBeUndefined();
     });
 
     it('should not truncate *theta* when longer than *r*', function() {
@@ -40,6 +44,39 @@ describe('Test scatterpolar trace defaults:', function() {
         expect(traceOut.r).toEqual([1, 2, 3]);
         expect(traceOut.theta).toEqual([1, 2, 3, 4, 5]);
         expect(traceOut._length).toBe(3);
+        expect(traceOut.r0).toBeUndefined();
+        expect(traceOut.dr).toBeUndefined();
+        expect(traceOut.theta0).toBeUndefined();
+        expect(traceOut.dtheta).toBeUndefined();
+    });
+
+    it('should coerce *theta0* and *dtheta* when *theta* is not set', function() {
+        _supply({
+            r: [1, 2, 3]
+        });
+
+        expect(traceOut.r).toEqual([1, 2, 3]);
+        expect(traceOut.theta).toBeUndefined();
+        expect(traceOut._length).toBe(3);
+        expect(traceOut.r0).toBeUndefined();
+        expect(traceOut.dr).toBeUndefined();
+        expect(traceOut.theta0).toBe(0);
+        // its default value is computed later
+        expect(traceOut.dtheta).toBeUndefined();
+    });
+
+    it('should coerce *r0* and *dr* when *r* is not set', function() {
+        _supply({
+            theta: [1, 2, 3, 4, 5]
+        });
+
+        expect(traceOut.r).toBeUndefined();
+        expect(traceOut.theta).toEqual([1, 2, 3, 4, 5]);
+        expect(traceOut._length).toBe(5);
+        expect(traceOut.r0).toBe(0);
+        expect(traceOut.dr).toBe(1);
+        expect(traceOut.theta0).toBeUndefined();
+        expect(traceOut.dtheta).toBeUndefined();
     });
 });