To Create a Variable with the name of a folder

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Peter 2015-1-2

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评论： Stephen23 2015-1-2

采纳的回答： Stephen23

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Hello!

I have a variable called this way;

workfolder='C:\Users\Jorge\Desktop\Work_Christmas\Measurements\rpm_measurements\rpm0800\';

And i would like to create another variable and it is the end of the name of my directory (workfolder), in order to use it with a loop, in this case it would be:

new_variable = rpm0800

How could i do it?

Thanks!

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Jan 2015-1-2

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Do you mean:

new_variable = 'rpm0800'

with the quotes?

Peter 2015-1-2

Yes exactly!

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Answer 1

Stephen23 2015-1-2

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编辑：Stephen23 2015-1-2

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While the question is rather unclear, it seems that the OP wishes to extract the last directory in the filepath string. This can be achieved using fileparts :

>> [A,B] = fileparts(workfolder(1:end-(workfolder(end)==filesep)))
A = 'C:\Users\Jorge\Desktop\Work_Christmas\Measurements\rpm_measurements'
B = 'rpm0800'

Note first this removes any trailing file separator character using the indexing of the workfolder string. An alternative is to use regexp to locate the last directory in the filepath string:

>> regexp(workfolder,'[^/\\]+(?=[/\\]?$)','once','match')
ans = 'rpm0800'

You should also have a good read of the MATLAB wiki, which covers all of these basic usage questions, with handy examples too:

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

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Peter 2015-1-2

Thank you very much Stephen, it worked

Stephen23 2015-1-2

My pleasure!

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Answer 2

Image Analyst 2015-1-2

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It's usually advised that you don't do that . However there is capability in MATLAB to do it and the FAQ shows some ways, such as using dynamic structure field names.

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Image Analyst 2015-1-2

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If, like I do, you have trouble figuring out complicated regexp expressions like '[^/\\]+(?=[/\\]?$)' , or would take too much time figuring that out, then you can use John D'Errico's incredibly handy and easy-to-use utility called allwords http://www.mathworks.com/matlabcentral/fileexchange/27184-allwords. It splits up the string into separate words and gives you control over the word separators. Here is some code that I think you'll find a lot easier to use and remember to use than those cryptic regexp expressions:

workfolder='C:\Users\Jorge\Desktop\Work_Christmas\Measurements\rpm_measurements\rpm0800\';
subFolders = allwords(workfolder, '\')
deepestFolder = subFolders{end}

I left off the semicolons at the end of the lines so you can see what it produces in the command window:

subFolders = 
    'C:'    'Users'    'Jorge'    'Desktop'    'Work_Christmas'    'Measurements'    'rpm_measurements'    'rpm0800'
deepestFolder =
rpm0800

What do you think, Peter? Is allwords() easier/simpler? Which do you prefer?

Stephen23 2015-1-2

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It is true that Regular Expressions have a rather cryptic syntax and can take a while to master, however they are a powerful tool that can be met in many different programming languages, and thus they are well worth the effort of learning. The fact that regexp is inbuilt means your code remains portable, without relying on any third-party functions (and licences...)

The example that Image Analyst gives above could also be achieved using standard MATLAB regexp:

>> regexp(workfolder,'\w+','match')
ans = {'C','Users','Jorge','Desktop','Work_Christmas','Measurements','rpm_measurements','rpm0800'}

Users wanting to practice and learn about Regular Expressions can try my compact Regular Expression Helper, which opens a figure and uses real-time updating of regexp's inputs and outputs to allow endless experimentation and refining of Regular Expressions:

http://www.mathworks.com/matlabcentral/fileexchange/48930-regular-expression-helper

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