How to read a variable whose suffix changes randomly?

Hi,everyone!

I have met a problem when ran a M program.

For example,running the program will product a variable as 'a_1'.And the number '1' is random.

Now,I want to get the value of 'a_number' and apply to myself M program.

How to do?

Thanks.

[madhan ravi]

Upload your code.

[MT_jsmith]

clear;
clc;

time_1=0;

time_2=0;

time_3=0;

mdfimport()%It is M.file and products two signals: P01_Line_*and time_*. 

           % * is a random number
  pause

if time_1~=0

      linet=time_1;

      pn=1;

elseif time_2~=0;

      linet=time_2;

      pn=2;

elseif time_3~=0

      linet=time_3;

      pn=3;

end

p11=sprintf('P01_Line_%d',pn);

P01=exist(p11);

if P01==1

      linep0=eval(p11);

end

[MT_jsmith]

If I need to deal with different signals,using mdfimport will product many variables . Is there a better way?

[Stephen23]

@MT_jsmith: if you are using this FEX submission, then no, there is no better way because unfortunately the author made some bad design decisions, and instead of simply returning a structure they make all of the variables magically appear in the workspace. Basically their bad design decision forces you to write bad code.

However there is a simple solution: download this much better designed tool:

https://www.mathworks.com/matlabcentral/fileexchange/47518-mdf_reader-zip

which lets you simply load into an output variable (a cell array):

data = importMDF3(...)

Note that the MATLAB Vehicle Network toolbox also supports reading MDF files:

https://www.mathworks.com/help/vnt/mdf-file-support.html

Answer 1

[madhan ravi]

Read the link below:

https://www.mathworks.com/matlabcentral/answers/304528-tutorial-why-variables-should-not-be-named-dynamically-eval

[MT_jsmith]

Thanks