Match hist bins

src/traces/histogram/calc.js

@@ -19,6 +19,7 @@ var binFunctions = require('./bin_functions');
 var normFunctions = require('./norm_functions');
 var doAvg = require('./average');
 var cleanBins = require('./clean_bins');
+var oneMonth = require('../../constants/numerical').ONEAVGMONTH;
 
 
 module.exports = function calc(gd, trace) {
@@ -27,60 +28,35 @@ module.exports = function calc(gd, trace) {
 
     // depending on orientation, set position and size axes and data ranges
     // note: this logic for choosing orientation is duplicated in graph_obj->setstyles
-    var pos = [],
-        size = [],
-        i,
-        pa = Axes.getFromId(gd,
-            trace.orientation === 'h' ? (trace.yaxis || 'y') : (trace.xaxis || 'x')),
-        maindata = trace.orientation === 'h' ? 'y' : 'x',
-        counterdata = {x: 'y', y: 'x'}[maindata],
-        calendar = trace[maindata + 'calendar'],
-        cumulativeSpec = trace.cumulative;
+    var pos = [];
+    var size = [];
+    var pa = Axes.getFromId(gd, trace.orientation === 'h' ?
+        (trace.yaxis || 'y') : (trace.xaxis || 'x'));
+    var maindata = trace.orientation === 'h' ? 'y' : 'x';
+    var counterdata = {x: 'y', y: 'x'}[maindata];
+    var calendar = trace[maindata + 'calendar'];
+    var cumulativeSpec = trace.cumulative;
+    var i;
 
     cleanBins(trace, pa, maindata);
 
-    // prepare the raw data
-    var pos0 = pa.makeCalcdata(trace, maindata);
+    var binspec = calcAllAutoBins(gd, trace, pa, maindata);
 
-    // calculate the bins
-    var binAttr = maindata + 'bins';
-    var autoBinAttr = 'autobin' + maindata;
-    var binspec = trace[binAttr];
-    if((trace[autoBinAttr] !== false) || !binspec ||
-            binspec.start === null || binspec.end === null) {
-        binspec = Axes.autoBin(pos0, pa, trace['nbins' + maindata], false, calendar);
-
-        // adjust for CDF edge cases
-        if(cumulativeSpec.enabled && (cumulativeSpec.currentbin !== 'include')) {
-            if(cumulativeSpec.direction === 'decreasing') {
-                binspec.start = pa.c2r(pa.r2c(binspec.start) - binspec.size);
-            }
-            else {
-                binspec.end = pa.c2r(pa.r2c(binspec.end) + binspec.size);
-            }
-        }
+    // the raw data was prepared in calcAllAutoBins (during the first trace in
+    // this group) and stashed. Pull it out and drop the stash
+    var pos0 = trace._pos0;
+    delete trace._pos0;
 
-        // copy bin info back to the source and full data.
-        trace._input[binAttr] = trace[binAttr] = binspec;
-        // note that it's possible to get here with an explicit autobin: false
-        // if the bins were not specified.
-        // in that case this will remain in the trace, so that future updates
-        // which would change the autobinning will not do so.
-        trace._input[autoBinAttr] = trace[autoBinAttr];
-    }
-
-    var nonuniformBins = typeof binspec.size === 'string',
-        bins = nonuniformBins ? [] : binspec,
-        // make the empty bin array
-        i2,
-        binend,
-        n,
-        inc = [],
-        counts = [],
-        total = 0,
-        norm = trace.histnorm,
-        func = trace.histfunc,
-        densitynorm = norm.indexOf('density') !== -1;
+    var nonuniformBins = typeof binspec.size === 'string';
+    var bins = nonuniformBins ? [] : binspec;
+    // make the empty bin array
+    var inc = [];
+    var counts = [];
+    var total = 0;
+    var norm = trace.histnorm;
+    var func = trace.histfunc;
+    var densitynorm = norm.indexOf('density') !== -1;
+    var i2, binend, n;
 
     if(cumulativeSpec.enabled && densitynorm) {
         // we treat "cumulative" like it means "integral" if you use a density norm,
@@ -89,13 +65,13 @@ module.exports = function calc(gd, trace) {
         densitynorm = false;
     }
 
-    var extremefunc = func === 'max' || func === 'min',
-        sizeinit = extremefunc ? null : 0,
-        binfunc = binFunctions.count,
-        normfunc = normFunctions[norm],
-        doavg = false,
-        pr2c = function(v) { return pa.r2c(v, 0, calendar); },
-        rawCounterData;
+    var extremefunc = func === 'max' || func === 'min';
+    var sizeinit = extremefunc ? null : 0;
+    var binfunc = binFunctions.count;
+    var normfunc = normFunctions[norm];
+    var doavg = false;
+    var pr2c = function(v) { return pa.r2c(v, 0, calendar); };
+    var rawCounterData;
 
     if(Array.isArray(trace[counterdata]) && func !== 'count') {
         rawCounterData = trace[counterdata];
@@ -104,7 +80,7 @@ module.exports = function calc(gd, trace) {
     }
 
     // create the bins (and any extra arrays needed)
-    // assume more than 5000 bins is an error, so we don't crash the browser
+    // assume more than 1e6 bins is an error, so we don't crash the browser
     i = pr2c(binspec.start);
 
     // decrease end a little in case of rounding errors
@@ -150,10 +126,11 @@ module.exports = function calc(gd, trace) {
     if(cumulativeSpec.enabled) cdf(size, cumulativeSpec.direction, cumulativeSpec.currentbin);
 
 
-    var serieslen = Math.min(pos.length, size.length),
-        cd = [],
-        firstNonzero = 0,
-        lastNonzero = serieslen - 1;
+    var serieslen = Math.min(pos.length, size.length);
+    var cd = [];
+    var firstNonzero = 0;
+    var lastNonzero = serieslen - 1;
+
     // look for empty bins at the ends to remove, so autoscale omits them
     for(i = 0; i < serieslen; i++) {
         if(size[i]) {
@@ -180,10 +157,181 @@ module.exports = function calc(gd, trace) {
     return cd;
 };
 
+/*
+ * calcAllAutoBins: we want all histograms on the same axes to share bin specs
+ * if they're grouped or stacked. If the user has explicitly specified differing
+ * bin specs, there's nothing we can do, but if possible we will try to use the
+ * smallest bins of any of the auto values for all histograms grouped/stacked
+ * together.
+ */
+function calcAllAutoBins(gd, trace, pa, maindata) {
+    var binAttr = maindata + 'bins';
+
+    // all but the first trace in this group has already been marked finished
+    // clear this flag, so next time we run calc we will run autobin again
+    if(trace._autoBinFinished) {
+        delete trace._autoBinFinished;
+
+        return trace[binAttr];
+    }
+
+    // must be the first trace in the group - do the autobinning on them all
+    var traceGroup = getConnectedHistograms(gd, trace);
+    var autoBinnedTraces = [];
+
+    var minSize = Infinity;
+    var minStart = Infinity;
+    var maxEnd = -Infinity;
+
+    var autoBinAttr = 'autobin' + maindata;
+    var i, tracei, calendar, firstManual;
+
+
+    for(i = 0; i < traceGroup.length; i++) {
+        tracei = traceGroup[i];
+
+        // stash pos0 on the trace so we don't need to duplicate this
+        // in the main body of calc
+        var pos0 = tracei._pos0 = pa.makeCalcdata(tracei, maindata);
+        var binspec = tracei[binAttr];
+
+        if((tracei[autoBinAttr]) || !binspec ||
+                binspec.start === null || binspec.end === null) {
+            calendar = tracei[maindata + 'calendar'];
+            var cumulativeSpec = tracei.cumulative;
+
+            binspec = Axes.autoBin(pos0, pa, tracei['nbins' + maindata], false, calendar);
+
+            // adjust for CDF edge cases
+            if(cumulativeSpec.enabled && (cumulativeSpec.currentbin !== 'include')) {
+                if(cumulativeSpec.direction === 'decreasing') {
+                    minStart = Math.min(minStart, pa.r2c(binspec.start, 0, calendar) - binspec.size);
+                }
+                else {
+                    maxEnd = Math.max(maxEnd, pa.r2c(binspec.end, 0, calendar) + binspec.size);
+                }
+            }
+
+            // note that it's possible to get here with an explicit autobin: false
+            // if the bins were not specified. mark this trace for followup
+            autoBinnedTraces.push(tracei);
+        }
+        else if(!firstManual) {
+            // Remember the first manually set binspec. We'll try to be extra
+            // accommodating of this one, so other bins line up with these
+            // if there's more than one manual bin set and they're mutually inconsistent,
+            // then there's not much we can do...
+            firstManual = {
+                size: binspec.size,
+                start: pa.r2c(binspec.start, 0, calendar),
+                end: pa.r2c(binspec.end, 0, calendar)
+            };
+        }
+
+        // Even non-autobinned traces get included here, so we get the greatest extent
+        // and minimum bin size of them all.
+        // But manually binned traces won't be adjusted, even if the auto values
+        // are inconsistent with the manual ones (or the manual ones are inconsistent
+        // with each other).
+        //
+        // TODO: there's probably a weird case here where a larger bin pushes the
+        // start/end out, then it gets shrunk and doesn't make sense with the smaller bin.
+        // Need to look for cases like this and see if the results are acceptable
+        // or we need to think harder about it.
+        minSize = getMinSize(minSize, binspec.size);
+        minStart = Math.min(minStart, pa.r2c(binspec.start, 0, calendar));
+        maxEnd = Math.max(maxEnd, pa.r2c(binspec.end, 0, calendar));
+
+        // add the flag that lets us abort autobin on later traces
+        if(i) trace._autoBinFinished = 1;
+    }
+
+    // do what we can to match the auto bins to the first manual bins
+    // but only if sizes are all numeric
+    if(firstManual && isNumeric(firstManual.size) && isNumeric(minSize)) {
+        // first need to ensure the bin size is the same as or an integer fraction
+        // of the first manual bin
+        // allow the bin size to increase just under the autobin step size to match,
+        // (which is a factor of 2 or 2.5) otherwise shrink it
+        if(minSize > firstManual.size / 1.9) minSize = firstManual.size;
+        else minSize = firstManual.size / Math.ceil(firstManual.size / minSize);
+
+        // now decrease minStart if needed to make the bin centers line up
+        var adjustedFirstStart = firstManual.start + (firstManual.size - minSize) / 2;
+        minStart = adjustedFirstStart - minSize * Math.ceil((adjustedFirstStart - minStart) / minSize);
+    }
+
+    // now go back to the autobinned traces and update their bin specs with the final values
+    for(i = 0; i < autoBinnedTraces.length; i++) {
+        tracei = autoBinnedTraces[i];
+        calendar = tracei[maindata + 'calendar'];
+
+        tracei._input[binAttr] = tracei[binAttr] = {
+            start: pa.c2r(minStart, 0, calendar),
+            end: pa.c2r(maxEnd, 0, calendar),
+            size: minSize
+        };
+
+        // note that it's possible to get here with an explicit autobin: false
+        // if the bins were not specified.
+        // in that case this will remain in the trace, so that future updates
+        // which would change the autobinning will not do so.
+        tracei._input[autoBinAttr] = tracei[autoBinAttr];
+    }
+
+    return trace[binAttr];
+}
+
+/*
+ * return an array of traces that are all stacked or grouped together
+ * TODO: only considers histograms. Should we also harmonize with bars?
+ * in principle people can mix and match these, but bars always
+ * specify their positions explicitly...
+ */
+function getConnectedHistograms(gd, trace) {
+    if(gd._fullLayout.barmode === 'overlay') return [trace];
+
+    var xid = trace.xaxis;
+    var yid = trace.yaxis;
+    var orientation = trace.orientation;
+
+    var out = [];
+    var fullData = gd._fullData;
+    for(var i = 0; i < fullData.length; i++) {
+        var tracei = fullData[i];
+        if(tracei.type === 'histogram' &&
+            tracei.orientation === orientation &&
+            tracei.xaxis === xid && tracei.yaxis === yid
+        ) {
+            out.push(tracei);
+        }
+    }
+
+    return out;
+}
+
+
+/*
+ * getMinSize: find the smallest given that size can be a string code
+ * ie 'M6' for 6 months. ('L' wouldn't make sense to compare with numeric sizes)
+ */
+function getMinSize(size1, size2) {
+    if(size1 === Infinity) return size2;
+    var sizeNumeric1 = numericSize(size1);
+    var sizeNumeric2 = numericSize(size2);
+    return sizeNumeric2 < sizeNumeric1 ? size2 : size1;
+}
+
+function numericSize(size) {
+    if(isNumeric(size)) return size;
+    if(typeof size === 'string' && size.charAt(0) === 'M') {
+        return oneMonth * +(size.substr(1));
+    }
+    return Infinity;
+}
+
 function cdf(size, direction, currentbin) {
-    var i,
-        vi,
-        prevSum;
+    var i, vi, prevSum;
 
     function firstHalfPoint(i) {
         prevSum = size[i];