How to assign a label to each bar in stacked bar graph?

I am trying to represent how job are assigned to different machines. Machines are represented as x-axis in stacked bar graph and job process time are the bars in the stacked bar graph. I want to label the bars to show which job the bar is representing. Can you please tell me or show me how to label the graph or alternatives.

Here is a scenario of my problem: Lets say I have 4 Jobs {J1 J2 J3 J4} and they been assigned to two machines {M1 M2} using list scheduling. Form the algorithm, let say Jobs J1 and J3 will be assigned to M1 and J2 and J4 assigned to M2. Now I will use stacked bar graph to represent how jobs been assigning to the machines. Now, i want to assign label to each bar individually or some sort of function that assign label to each bar then it would be great. Thanks in advance :)

Answer 1

[Star Strider]

I am not exactly certain what you want, so you may have to experiment with this:

D = randi(10, 5, 3);

figure(1)
hBar = bar(D, 'stacked');
xt = get(gca, 'XTick');
set(gca, 'XTick', xt, 'XTickLabel', {'Machine 1' 'Machine 2' 'Machine 3' 'Machine 4' 'Machine 5'})
yd = get(hBar, 'YData');
yjob = {'Job A' 'Job B' 'Job C'};
barbase = cumsum([zeros(size(D,1),1) D(:,1:end-1)],2);
joblblpos = D/2 + barbase;
for k1 = 1:size(D,1)
    text(xt(k1)*ones(1,size(D,2)), joblblpos(k1,:), yjob, 'HorizontalAlignment','center')
end

produces this plot:

[Mrugesh Patel]

Hi, You have same problem as the guy above but still thanks for answering my question. I want each bar needs to have a different label of the job. Example: Lets say I have 4 Jobs {J1 J2 J3 J4} and they been assigned to two machines {M1 M2} using list scheduling. Form the algorithm, let say Jobs J1 and J3 will be assigned to M1 and J2 and J4 assigned to M2. Now I will use stacked bar graph to represent how jobs been assigning to the machines. The problem with your code is that 4 jobs have the same label. I want to assign label to each bar individually or some sort of function that assign label to each bar. Thanks. I really appreciate it :)

[Star Strider]

I only needed to make a couple small changes in my code to make it work with your changed requirements:

D = randi(10, 2, 2);        % Rows = Machines,  Columns = Jobs

figure(1)
hBar = bar(D, 'stacked');
xt = get(gca, 'XTick');
set(gca, 'XTick', xt, 'XTickLabel', {'Machine 1' 'Machine 2'})
yd = get(hBar, 'YData');
yjob = {'Job #1' 'Job #2' 'Job #3' 'Job #4'};
barbase = cumsum([zeros(size(D,1),1) D(:,1:end-1)],2);
joblblpos = D/2 + barbase;
for k1 = 1:size(D,1)
    text(xt(k1)*ones(1,size(D,2)), joblblpos(k1,:), yjob(k1:2:end), 'HorizontalAlignment','center')
end
axis([0.5  2.5    ylim*1.1])

produces this figure:

You may want to experiment with the colours of the bars and text. See the documentation for bar, Barseries Properties, and text for those details.

[Mrugesh Patel]

OMG!!! You are life saver. Thank you so much. I really appreciate your help. I need one more favour though. Can you please walk through the code or add comments on what each code does. I really need to understand it to use it plus I want to learn how it work as well. If it is too much then don't worry, you already have done me a great favour. Thank you once again :)

[Star Strider]

My pleasure!

The ‘hBar’ assignment for the bar call allows the rest of the code to access data the bar plot uses to plot the bars.

The ‘xt’ assignment gets the 'XTick' data. The subsequent set call labels the 'XTick' locations with the machine number instead of the number originally assigned to them.

The ‘yjob’ assignment creates a cell vector of strings to later label the jobs.

The ‘barbase’ assignment calculates the lower borders of the bars in units of the y-axis. It ‘pads’ them with an initial vector of zeros, because the lowest of the stacked bars starts at zero (in this instance).

The ‘joblblpos’ (‘job label position’) variable takes the information from the ‘D’ array (it could also take it from the 'YData' array) and calculates midpoints between the lower and upper bar ends, so it can position the labels correctly.

The for loop labels the bars, using the text function. The ‘yjob’ variable here uses ‘yjob([1 3])’ in the first iteration of the loop and ‘yjob([2 4])’ in the second iteration because of the sequential way I created ‘yjob’. It centres them using the 'HorizontalAlignment' name, set to the value of 'center'.

The axis call gives a bit of room between the bar left and right borders and the sides of the plot box, and between the top of the tallest bar and the top of the plot box. I did not edit the code to provide this, but a neater solution would be: axis([0.5 2.5 ceil(ylim*1.1)]). (This only affects the upper limit of ylim, because the lower limit is zero.)

I will be glad to provide more detail if any of this is not clear.

As always, my pleasure!

[Mrugesh Patel]

Hi, Thanks for the explanation. I understand it now. Using the code you provided, I tried to create barh stacked graph but i kept on getting error. I tried few changes like changing the labels of the axis and so on to work for barh graph but I failed. Does it require a big change or am i doing something wrong?

Here is my Code for normal stacked bar Graph:

G=[1 2 1 1 2 2 1 2; 2 9 6 5 3 7 9 10; 0 0 2 8 9 12 13 19] %first row= what machine job been assigned to, second row= process time, third row= start time

m=2; %number of machines

U=[2 6 5 9; 9 3 7 10] % equals D in your code

ST=[0 2 8 13; 0 9 12 19] % This is start time of each job

barg=bar(U,'stacked'); % graph

xt = get(gca, 'XTick'); 

set(gca, 'XTick', xt, 'XTickLabel', {'Machine 1' 'Machine 2'}); 

yd = get(barg, 'YData'); 

yjob = {'Job #1' 'Job #3' 'Job #4' 'Job #7' 'Job #2' 'Job #5' 'Job #6' 'Job #8'}; 

joblblpos = U/2 + ST; 

ms=0; %initial value

for k1 = 1:m %number of machines
      Y=G(:,G(1,:)==k1);
      [~,z] = size(Y); % works out how many jobs need to be labeled for machine k1

        text(xt(k1)*ones(1,z), joblblpos(k1,:), yjob((ms+1):1:(ms+z)), 'HorizontalAlignment','center') 
        ms=ms+z; %total jobs labeled
      end         
      axis([0.5  2.5    ylim*1.1])

This works perfectly fine for bar(U,'stacked') graph but when I try to create barh(U,'stacked') graph, I don't get a proper graph even when i swap the axis label. I think i am doing something wrong or forgetting to change something. Can you help me for hopefully the last time :D lol

Thanks for everything once again :)

[Star Strider]

The horizontal bar plot, barh, is completely different. Because of the way it works, it would require different coding, and I am not certain it would work with the data you have, because the job labels would still be horizontal and so would likely not fit — and would likely extend outside their own bar segments and into the adjacent stacked bar for the same machine — for the very narrowest horizontal bar segments.

Please just use the regular bar plot, since it works.

[Mrugesh Patel]

I see your point. I will stick to vertical bar plot. Thanks for the advice

[Star Strider]

My pleasure!

[Dawid Dybowski]

The code for horizontal bar plot:

D = randi(10, 5, 3);
figure(1)
hBar = barh(D, 'stacked');
yt = get(gca, 'YTick');
set(gca, 'YTick', yt, 'YTickLabel', {'Machine 1' 'Machine 2' 'Machine 3' 'Machine 4' 'Machine 5'})
yjob = {'Job A' 'Job B' 'Job C'};
barbase = cumsum([zeros(size(D,1),1) D(:,1:end-1)],2);
joblblpos = D/2 + barbase;
for k1 = 1:size(D,1)
    text(joblblpos(k1,:), yt(k1)*ones(1,size(D,2)), yjob, 'HorizontalAlignment','center')
end

Answer 2

[dpb]

>> y=rand(4,5)*10;
>> bar(y,'stacked')
>> job=num2str([1:5].','Job %d');
>> legend(job,'location','northwest')
>>

[Mrugesh Patel]

Hi, Thanks for answering my question. This is great but there is one problem. Each bar needs to have a different label of the job. Example: Lets say I have 4 Jobs {J1 J2 J3 J4} and they been assigned to two machines {M1 M2} using list scheduling. Form the algorithm, let say Jobs J1 and J3 will be assigned to M1 and J2 and J4 assigned to M2. Now I will use stacked bar graph to represent how jobs been assigning to the machines. The problem with your code is that 4 jobs have the same label. I want to assign label to each bar individually or some sort of function that assign label to each bar then it would be great. Thanks in advance. I really appreciate it :)