Stacked bar chart in MATLAB

Question

I'm trying to create a bar chart in MATLAB where bar positions are in one column, bar heights are in another, and the bars are stacked whenever two or more positions overlap.

To illustrate, here is the same chart created in R with ggplot:

library(ggplot2)

data <- data.frame(name=c('A', 'B', 'C', 'D', 'E', 'F'),
                   pos=c(0.1, 0.2, 0.2, 0.7, 0.7, 0.9),
                   height=c(2, 4, 1, 3, 2, 1))

ggplot(data, aes(x=pos, y=height, fill=name)) +
  geom_bar(stat='identity', width=0.05)

For comparison, in MATLAB, the same data looks like:

data = [ 0.1, 0.2, 0.2, 0.7, 0.7, 0.9; ... 
    2, 4, 1, 3, 2, 1]';

But I can't figure out whether there's a combination of parameters to the bar function to create the same sort of stacked bar chart.

Possible duplicate of [Combine the 'grouped' and 'stacked' in a BAR plot?](https://stackoverflow.com/questions/21304962/combine-the-grouped-and-stacked-in-a-bar-plot) — Anthony, Nov 06 '18 at 22:05
@Anthony: It's not grouping. It's stacking with each bar having a different color, so not a duplicate. — gnovice, Nov 06 '18 at 22:10

gnovice · Accepted Answer · 2018-11-06T22:20:53.513

Here's one way to accomplish this (it's a bit trickier in MATLAB):

[binCenters, ~, binIndex] = unique(data(:,1));
nBins = numel(binCenters);
nBars = numel(binIndex);
barData = zeros(nBins, nBars);
barData(binIndex+nBins.*(0:(nBars-1)).') = data(:, 2);
bar(binCenters, barData, 'stacked');
legend('A', 'B', 'C', 'D', 'E', 'F');

The key is to format the data passed to bar into a matrix such that each row contains values for one stack, and each column will be a different grouping with different colors. Basically, barData ends up being mostly zeroes with one non-zero value per column:

barData =

     2     0     0     0     0     0
     0     4     1     0     0     0
     0     0     0     3     2     0
     0     0     0     0     0     1

Stacked bar chart in MATLAB

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