Dataframe (#576)

* initial dataframe commit

* initial dataframe port of core app

* rename variables for clarity

* remove unused import

* comment out unused code

* fix array handling bug in crossfilter dimension creation

* allow creation of empty dataframes

* handle non-existent columns

* handle non-existent columns

* revise tests for new dataframe

* comments for clarity

* comments for clarity

* generate bulk add placeholder with real gene names

* fix bug in gene name adding

* more dataframe unit tests

* fix bug - subset from current world, not universe

* put cut and pasted code into a single function

* improve caching of crossfilter

* remove cascading update bug from graph

* more performance work

* improve state handling for scatterplot

* performance optimization of critical path

* add column summarization

* dataframe utils

* add callOnceLazy

* fix tests

* minor updates found during review

* fix misspelling

* remove RESTv02 from function names

* comment cleanup

* cut/icut col parameter defaults to null

* break up large test

* improve tests and comments on dataframe at/has functions

client/src/components/brushableHistogram/index.js

@@ -35,9 +35,11 @@ class HistogramBrush extends React.Component {
       .scaleLinear()
       .range([this.height - this.marginBottom, 0]);
 
-    if (obsAnnotations[0][field] !== undefined) {
+    if (obsAnnotations.col(field)) {
       // recalculate expensive stuff
-      const allValuesForContinuousFieldAsArray = _.map(obsAnnotations, field);
+      const allValuesForContinuousFieldAsArray = obsAnnotations
+        .col(field)
+        .asArray();
 
       histogramCache.x = d3
         .scaleLinear()
@@ -149,7 +151,7 @@ class HistogramBrush extends React.Component {
       initializeRanges
     } = this.props;
 
-    if (obsAnnotations[0][field]) {
+    if (obsAnnotations.col(field)) {
       dispatch({
         type: "color by continuous metadata",
         colorAccessor: field,