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Plotting results of three different data sets on same Plot

Asked by Ben Brooke on 13 Apr 2012
Hi,
I would like to compare the velocity profiles of three different data sets, contained within three different folders. How would I go about writing the code for a function to import the three data sets and plot them all on the same graph so that they can be compared with one another. I would like to be able to change the name of the files to be imported in the code so it can reused for different examples.
I imagine this should be fairly simple, however I'm still very new to Matlab so getting a bit stuck.
Thanks

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3 Answers

Answer by laurie
on 13 Apr 2012
 Accepted Answer

How about:
load file1.mat
data1=data;
load file2.mat
data2=data
hold all
plot(data1)
plot(data2)
data1 and data2 must be the same length though I think.
About the different folders: I think if you add all the folders to the path (manually?) it should work fine.
Cheers

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data1 and data2 do not need to be the same length, as the syntax you have shown will simply plot the data against the index. Also, you do not necessarily need to add the folders to the path-- you can use 'load' with a full file path. In fact, this is necessary if there are multiple files with the same name in different directories.
Thanks. I managed to make some alterations but used your basis. Cheers!
thanks :) i am glad i can both help and learn new things about matlab

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Answer by Vaibhav
on 13 Apr 2012

The code above would work. Another alternative is to
plot(x,y1,x,y2,x,y3)
If x is not same for all 3 sets, then
plot(x1,y1,x2,y2,x3,y3)
But x1,x2,x3 must be the same length.

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Answer by Matt Kindig on 13 Apr 2012

Depending on the format of the data sets, there are a variety of functions available to import the data. Look at the following to get you started (these are references to topics in Matlab help):
doc load
doc importdata
doc dlmread
doc textscan
To plot data:
doc plot
doc hold
To change the names of the files, I would probably have one of the function inputs be a cell array with the filenames, and have a for loop in the function to iterate through each data set and do the plotting.
doc cell
doc for

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