Clear Filters
Clear Filters

Plot bar chart from elements of string

24 views (last 30 days)
I want to create a bar graph showing the number eruptions for the respective countries. However, the data provided is in a string and I need to loop through the data set to count the respective countries. As it is in a string format, I am struggling to extract out the number of counts for each country in a loop. I managed to use strcmp and find, but the plot does not work. How do I create a loop which plots the chart sucessfully?
% Finding each individual country "eachcountry"
eachcountry = unique(thecountry);
% Counting the length of year for j
% loop through each index
for j = 1:length(thecountry)
A = strcmp('%s'eachcountry(j),thecountry);
% Obtaining index of respective country
indexcountry = find(A)
numberofcounts = numel(indexcountry);
% Plotting with rectangle function, start from the first year, for x axis,
% start from 0 for y axis. Width is 1, while frequency is number of
% counts.
rectangle('Position',[eachcountry(j) 0 1 numberofcounts])
hold on
end
% Labelling axes
xlabel('Country')
ylabel('Frequency')

Accepted Answer

Stephen23
Stephen23 on 26 Sep 2018
Edited: Stephen23 on 26 Sep 2018
>> [U,~,X] = unique(thecountry);
>> cnt = histc(X,1:numel(U));
>> bar(cnt)
creates this:
You might want to read this too:
  2 Comments
Madlab
Madlab on 26 Sep 2018
Thank you very much for your input. What I am trying to plot is more like this image here, showing the counts for each respective country. That is why I am trying to utilise the loop to count each country and plot it.
Stephen23
Stephen23 on 26 Sep 2018
Edited: Stephen23 on 26 Sep 2018
@Madlab: see my edited answer, which plots the number of eruptions for each country. No loops are required. You can easily add country labels too:
>> set(gca,'XTick',[])
>> cellfun(@(x,s)text(x,-1,s,'Rotation',270),num2cell(1:numel(U)),U.')
Giving:
With newer MATLAB versions you can simply add the names as XTickLabel and set the XTickLabelRotation directly, no need for text.

Sign in to comment.

More Answers (1)

jonas
jonas on 26 Sep 2018
Edited: jonas on 26 Sep 2018
something like this?
n=ones(size(thecountry))
[G,ctr]=findgroups(thecountry)
nrupt=splitapply(@sum,n,G)
bar(nrupt)
set(gca,'xtick',1:size(nrupt,1),'xticklabel',ctr,'xticklabelrotation',90,'fontsize',7,'ticklength',[0 0])

Categories

Find more on Line Plots in Help Center and File Exchange

Community Treasure Hunt

Find the treasures in MATLAB Central and discover how the community can help you!

Start Hunting!