Plotting results of three different data sets on same Plot

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

Answer 1

[laurie]

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

[Matt Kindig]

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.

[Ben Brooke]

Thanks. I managed to make some alterations but used your basis. Cheers!

[laurie]

thanks :) i am glad i can both help and learn new things about matlab

Answer 2

[Vaibhav]

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.

[Martin Llorens]

But if i want to plot also a tendency line, how i would do it?

Answer 3

[Matt Kindig]

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