[pof] add 'cumulative' histogram 'mode' for CDF

Author: etpinard

src/traces/histogram/attributes.js

@@ -71,6 +71,16 @@ module.exports = {
         ].join(' ')
     },
 
+    mode: {
+        valType: 'enumerated',
+        values: ['density', 'cumulative'],
+        dflt: 'density',
+        role: 'info',
+        description: [
+            ''
+        ].join('')
+    },
+
     autobinx: {
         valType: 'boolean',
         dflt: null,

src/traces/histogram/calc.js

@@ -38,6 +38,7 @@ module.exports = function calc(gd, trace) {
 
     // prepare the raw data
     var pos0 = pa.makeCalcdata(trace, maindata);
+
     // calculate the bins
     if((trace['autobin' + maindata] !== false) || !(maindata + 'bins' in trace)) {
         trace[maindata + 'bins'] = Axes.autoBin(pos0, pa, trace['nbins' + maindata]);
@@ -112,6 +113,8 @@ module.exports = function calc(gd, trace) {
     // average and/or normalize the data, if needed
     if(doavg) total = doAvg(size, counts);
     if(normfunc) normfunc(size, total, inc);
+    if(trace.mode === 'cumulative') cdf(size);
+
 
     var serieslen = Math.min(pos.length, size.length),
         cd = [],
@@ -140,3 +143,9 @@ module.exports = function calc(gd, trace) {
 
     return cd;
 };
+
+function cdf(size) {
+    for(var i = 1; i < size.length; i++) {
+        size[i] += size[i - 1];
+    }
+}

src/traces/histogram/defaults.js

@@ -26,6 +26,7 @@ module.exports = function supplyDefaults(traceIn, traceOut, defaultColor, layout
     var x = coerce('x'),
         y = coerce('y');
 
+    coerce('mode');
     coerce('text');
 
     var orientation = coerce('orientation', (y && !x) ? 'h' : 'v'),