This is a known issue in Matlab’s high-level functions (plot, stem, mesh, etc.). For example,

plot(1:3, 2:2:6, '*');
axis([0 4 0 8])

will always plot a single line; but if we insist on three distinct lines, we must resort to the aforementioned NaN trick:

plot([1:3; 2:4], [2:2:6; nan(1,3)], '*'); 
axis([0 4 0 8])

However, using NaN-s has a clear disadvantage in code readability and the requirement of many additional check-ups, which are better to be avoided in the first place. @Yair, is there any (undocumented) way to force Matlab to behave in a discrete level?

@Yaroslav – I am not aware of any simple way to do this without using either NaNs or low-level plotting functions.

Thanks for raising this.

In 2012 I sent the following report to the MathWorks (with respect to R2011a that I was running at the time):

The commands

bar(1, 1:5, 'grouped')
bar(1, 1:5, 'stacked')

report an error “X must be same length as Y”.

But according to documentation for the grouped or stacked options, each row of Y is an observation group and we require only numel(X)==size(Y,1) for this case. I expect to see a single stack or group plotted for such a call. On the other hand

bar(1, (1:5)', 'grouped')

would be expected to generate the error given.

My point was not accepted, but they keep changing the documentation in this area. In R2013a (that I use today) the documentation is not consistent between Grouped and Stacked. Looking at R2014a on MathWorks web-site there is the getout statement,

“If Y is a vector of length n, then MATLAB treats Y as a column vector and displays n bars.”

In my opinion this is a kludge. The doc is now mutually contradictory while the behaviour sucks! Clearly if you explicitly choose a grouped or stacked bar chart, by passing the flag, then orientation of matrix Y matters, and each row of Y is a group. It is quite legitimate to plot a single stack, and this is what we should expect bar() to do in that case.

Thanks a lot for the very useful resource, Yair. Indeed in HG1 bar series can be treated as a set of patches and one can change a transparency using, e.g.

hb = bar(...);
hp = arrayfun(@(x) allchild(x), hb);
set(hp, 'FaceAlpha', 0.5)

However in HG2 this code won’t work since bar object has no children. Do you know how to tackle this problem? Thanks a lot in advance!

@Sergey –
To set all bar faces to the same color and alpha:

hBar = bar(...);
hBar.Face.ColorType = 'truecoloralpha';  % default is 'truecolor' without alpha
hBar.Face.ColorData = uint8([53;142;134;128]);   % 128=50% alpha

We can see the possible ColorType values by typing hBar.Face.ColorType='<TAB>. We get the following list: colormapped, texturemapped, truecolor (default), truecoloralpha.

We can see the possible ColorData values by trying some obviously invalid value:

>> hBar.Face.ColorData = 1
While setting the 'ColorData' property of Quadrilateral:
Value must be one of the following:
Truecolor  - a 4xN array of type uint8
Colormapped - a 1xN vector of type single
Texturemapped - a 2xN array of type single 

This seems to indicate that there’s a way to set a 4xN color array, presumably for the separate bar faces (patches). Unfortunately, setting such an array directly is not enough:

>> hBar.Face.ColorData = uint8([53,40,100; 42,0,100; 134,50,100; 120,50,100]);
Warning: Error creating or updating Quadrilateral
 Error in value of property  ColorData
 Array is wrong shape or size
(Type "warning off MATLAB:gui:array:InvalidArrayShape" to suppress this warning.)

So apparently we need to set some other property before being able to do this. I have still not found out exactly how to do this. If anyone finds out, please post a follow-on comment here. For reference, here’s what the Face object looks like:

>> hBar.Face.get
             AmbientStrength: 0.3
             BackFaceCulling: 'none'
                ColorBinding: 'object'
                   ColorData: [4x1 uint8]
                   ColorType: 'truecoloralpha'
             DiffuseStrength: 0.6
            HandleVisibility: 'on'
                     HitTest: 'off'
                       Layer: 'middle'
               NormalBinding: 'none'
                  NormalData: []
                      Parent: [1x1 Bar]
    SpecularColorReflectance: 1
            SpecularExponent: 10
            SpecularStrength: 0.9
                   StripData: [1 5 9 13]
                     Texture: []
            TwoSidedLighting: 'off'
                  VertexData: [3x12 single]
               VertexIndices: []
                     Visible: 'on'

Anyway, this is not a major limitation since we normally want all our bar faces to have consistent color and alpha. We can always use multiple bars, each having different color/alpha:

data = [6,4,1; 5,2,2; 4,0,0; 2,0,1; 0,2,0; 0,1,1];
hBar = bar(data,'stacked');

% Set the middle bar's color to translucent red
hBar(2).Face.ColorType = 'truecoloralpha';
hBar(2).Face.ColorData = uint8([255; 0; 0; 100]);

Thank you very much, Yair. Apparently I need to read more about the HG2 and use “if-s” in my code for compatibility.

or use try/catch

Here’s how to get multiple colors in a single Bar series. The ColorBinding can also be ‘interpolated’.

hBar = bar(...);
hBar.Face.StripData = [];
vi = [1:4:N*4; 2:4:N*4; 4:4:N*4; 3:4:N*4];
hBar.Face.VertexIndices = uint32(vi(:)');
hBar.Face.ColorBinding = 'discrete';
hBar.Face.ColorData = ... % 4xN uint8

Yair (or anyone),

I have an application where I need to color the bars individually, and have tried to figure out how to get the handles of the underlying patches or graphical objects. I am doing this in HG2. Any ideas?

Thank you,
Mike

So far, a smart solution is elusive; you can inspect Yair’s ^[7] for a detailed analysis. In the meanwhile, you can try the old-school simple approach:

N = 15;
hAxes = axes('NextPlot','add');
facecolors = jet(N);
for i = N : -1 : 1
    hBar(i) = bar(i, 2*i, 'FaceColor',facecolors(i,:));
end

Hi
I used the following code.
But I wanted to display the ranges of each stacked portion along its bar.
Please share if anyone knows how to display the ranges (limits of the each portion).

Y = [5 1 2; 8 3 7; 9 6 8; 5 5 5; 4 2 3];  % sample data from bar example...
Z=cumsum(Y,2);                            % bar cumulative heights for positioning
X=repmat([1:5].',1,3);                    % x locations for each Y
bar(Y,'stack')                            % base stacked bar
colormap(copper);                         % change color map
arrayfun(@(x,y,z) text(x,y,num2str(z), 'horizontalalign','center', 'verticalalign','top', 'color','w'), X,Z,Y);

% write the labels for each subset
sumTotals = sum(Y,2);
sumTotals = sumTotals(~isnan(sumTotals));
labels = arrayfun(@num2str,sumTotals,'uniform',false);
hText = text(1:size(Y,1), sumTotals, labels);
set(hText, 'VerticalAlignment','bottom', 'FontSize',8, 'Color','k');

how to display the stack values for horizontal bar graph

@NG – you will need to adapt the code in my post. This should not be too difficult: all the components are there, it’s basically just switching between X-Y etc., so I am not going to spoon-feed the answer. If you cannot do this (or don’t have time), then contact me by email for a short consulting.

Thanks for this solution. In addition to needing to label the individual bars, I have floating point numbers as the labels at the tops of the bars. Is there a way to center those labels over the bars instead of starting the text at the mid-point of each bar?

Hi. I have a problem with making scatered bar graph in matlab.

I need to create graph where on X axis will be years from 2005 to 2016 and on Y axis will be another numbers.
If I use just simple number for example from 1 to 10 for X axis is working, but I need put years on X axis.

I use this example from web:

measles = [38556 24472 14556 18060 19549 8122 28541 7880 3283 4135 7953 1884]';
mumps = [20178 23536 34561 37395 36072 32237 18597 9408 6005 6268 8963 13882]';
chickenPox = [37140 32169 37533 39103 33244 23269 16737 5411 3435 6052 12825 23332]';

% Create a stacked bar chart using the bar function
figure
bar(1:12, [measles mumps chickenPox], 0.5, 'stack')

% Adjust the axis limits
axis([0 13 0 100000])
set(gca, 'XTick', 1:12)

% Add title and axis labels
title('Childhood diseases by month')
xlabel('Month')
ylabel('Cases (in thousands)')

% Add a legend
legend('Measles', 'Mumps', 'Chicken pox') 

But then I repleaced nummbers for X axis (how you can see below), nad now is not working.
Some advice in this issue for me?

% Create data for application of fertilizer in arable land
dusikate = [70147.6	84165.8	92217.6	73166.4	85068.2	90982.2	98787.2	110714.4 116029.5 111892.1]';
fosforecne = [15757.9 19187.6 19828.2 13866.1 12797.9 14982.2 18898 20306.7 22497.4 21286.5]';
draselne = [13698.8	15764.6	16232.1	9798.1 8002.1 10108.4 13038.3 14534.1 16366.4 15868.7]';

x = 2005:1:2016;

% Create a stacked bar chart using the bar function   
figure
bar(x,[dusikate fosforecne draselne], 0.8, 'stack')

% Adjust the axis limits
axis([50000 180000])
set(gca, 'XTick', x)
ax = gca; 
ax.YAxis.Exponent = 0;

% Add title and axis labels
title({'Celková spotreba draselných, fosforečných a dusíkatých hnojív (v tonách) na';'sledovanej výmere ornej pôdy na Slovensku v období rokov 2005/2006 - 2014/2015'})
xlabel('sezóna (hospodársky rok')
ylabel('spotreba hnojív v tonách [t]')

% Add a legend
legend('dusikaté', 'fosforečné', 'draselné')