Macros in Matlab - repeating simple instructions

Hi there,

I have read on some websites that writing macros for Matlab is not advisable? I am trying to write several as I am about to be embarking on the same process for a number of different data sets. twenty five to be exact. I would like to do simple things like write macro to call my data set put it through two or three functions that I have written and then save the results in a particular place. Is that possible? Is there any good literature I can get on the topic?

[Bran]

Also I was wondering if there was a way to get the script to run operations in batches for example I need to use my fucntion on various files and run it through the night so I want to write a macro that can tell me prgram to switch files after the results have been obtained.

[Iain]

It kinda depends what you mean by "macro". VB macros can be functions or subs, but you can access them like shortcuts.

Answer 1

[Iain]

Step 1: Write a "function" that takes as input, an argument for filename in, and filename out, opens & reads your input file, does the operations to it, and saves the output in the desired output filename.

Step 2: Write a script that feeds the appropriate input & output filenames to that function.

Step 3: Run the script.

Eg, file1, called "fred.m"

 function fred(in,out)
 x = load(in); % or importdata or csvread or xlsread or whatever your reading function is.
 y = sin(x);
 save(out,'y')

file 2: called "process_it_all"

 in = {'file1.mat','file2.mat'};
 out = {'wibble','wobble'};

 for i = 1:numel(in)
  fred(in{i},out{i})
 end

[Bran]

Hi Iain,

So sorry to add this comment so late. I was wondering if you could help. your suggestion has been throwing up errors for me. I thought a function should be defined as [out] = function (in) Also what if I want the function to do two things, should that then be [out,out2] = function(in,in2) also it keep telling me that load should be loading up a string. It doesn't seem to be able to recognize that in already has strings. Any ideas?

many thanks in advance

Answer 2

[Walter Roberson]

For something like that you would likely be better off writing functions.

But yes, you can write scripts. scripts run in the context of the current workspace.

[covariant_cat]

How do you deal with import? Neither another function nor another script can import packages for a function.

Answer 3

[Bran]

Hi guys

Thanks so much for the help I also wanted to check something say for example I wanted to plot a graph of y = sin(x) for example and save it to a particular folder ofor each loop how would I go about this?

Would something like this work?

baseFileName = sprintf(out2,k);
% Specify some particular, specific folder:
fullFileName = fullfile('D:\myPlots', baseFileName);  
figure(1); % Activate the figure again.
export_fig(fullFileName); % Using export_fig instead of saveas.