How to concatenate variables in different matlab files?

I have two mat files with identical number of variables.

In file1.mat

Variables

Time [100X1] double

Force [100x1] double

In file2.mat

Variables

Time_1 [90X1] double

Force_1 [90x1] double

I would like to vertically concatenate these variables. The suffix '_1' is constant for all variables in one file, but changes from file to file.

Thanks

Answer 1

[Image Analyst]

bothTimes = [Time; Time_1];
bothForces = [Force; Force_1];

By the way, you would make it simpler if all files just saved the same variable and called it Time. Then you could simply do

    s1 = load(fullFIleName1);
    s2 = load(fullFileName2);

    bothTimes = [s1.Time; s2.Time];
    bothForces = [s1.Force; s2.Force];

and your code would not have to worry about whether the name of the variable had a _1 or _2 or _3 in it.

You can use the fieldnames() function to find out the name of what's in your s1 or s2. But then you have to use dynamic fieldnames or just try every possibility if you're going to have numbers hard coded into the variable names.

[Prasanna Srisailan]

Good start. Let me investigate on dynamic field names since the variables are unknown to me. Thanks

[Image Analyst]

Uh, yeah but in case you didn't notice that was what I was hoping you wouldn't do. Is there any reason why your other code MUST create variables with different names? Maybe you think it will make things easier down the line, but it doesn't. Like I said, the preferred way was to have the other function just save the mat files with all the variables in it having the same name. If you insist on doing it the hard way, then see Aaditya's method below which uses dynamic field names.

[Prasanna Srisailan]

The reason is, there is already existing data with different suffixes added to the variables in different files. So I have try out all possibilities to find the right match.

Answer 2

[Aaditya Kalsi]

You can do this quite simply:

% load initial data
filedata = load('file1.mat');
Time = filedata.Time;
Force = filedata.Force;

num_more_files = 2 % say i had two more mat-files

for i = 1:num_more_files
    var_appended_str = ['_' num2str(i)];
    filename = ['file' num2str(i) '.mat'];

      filedata = load(filename);
      Time = [Time; filedata.(sprintf(['Time' var_appended_str]))];
      Force = [Force; filedata.(sprintf(['Force' var_appended_str]))];
end

This code has not been tested but you get the idea.

Hope this helps.

Answer 3

[Walter Roberson]

http://matlab.wikia.com/wiki/FAQ#How_can_I_process_a_sequence_of_files.3F

http://matlab.wikia.com/wiki/FAQ#How_can_I_create_variables_A1.2C_A2.2C....2CA10_in_a_loop.3F