Concatenate variable value and variable name into new variable name.

I would like to have the name of a variable into another variable name.

So if for example I define

animal = 'cat' and make some calculation: eg. mean. I would like a variable name which concatenates these two: 'cat_mean'.

So if swap to animal = 'dog' there will be created another variable named 'dog_mean'

Best regards Jesper

Answer 1

[Adam]

Why would you want to do this though? A variable name is just a handle used in code. Suppose you create these dynamic variable names. Now everywhere afterwards in the code you have to keep working with these and using ugly code constructs to do so because you can't just refer to a variable properly by its name in the code.

Just use a struct if you want to do something like this e.g.

cat.mean = ...
dog.mean = ...

or if you only want one variable rather than separate ones for cat, dog, etc

animal.type = cat;
animal.mean = ...

animal(2).type = 'dog'
animal(2).mean = ...

[Jesper Steen Andersen]

Thank you for your reply.

First of all, because I am beginner at MATLAB and I do not know how else to get my problem fixed. I have various folders containing csv-files with data calculated for a lot of files. The folders are named depending on what aspect (feature) of files is calculated. In the first part of my script I define this feature-variable and I use 'strcat' to construct the filenames that I read into MATLAB via "csvread".

In the next part I calculate different sorts of statistical properties of each files (mean, median, std). At the moment, it would be convenient to name these statistical properties so that I know what 'feature' they were calculated for. And I thought that renaming them was a way to do it. But there might be much better ways?

[Adam]

Well, basically using structs as above

doc struct

will help give you the equivalent flexibility in naming whilst still allowing you to access these variables easily.

For example, you can do with struct fields what you cannot easily do with variable names - i.e. use a dynamic string to access into them e.g.

feature = 'someFeature';

myStruct.( feature ) = featureVal;

This will create a field on your structure as

myStruct.someFeature

in the same way as if you had just hard-coded that, but allowing you to have read that string dynamically from, for example, a filename.

[Jesper Steen Andersen]

Perfect! This helped me. Thanks a lot!

Answer 2

[Orion]

Hi,

something like :

animal = 'cat';
operation = 'mean';

result = horzcat(animal,'_',operation)

Answer 3

[Azzi Abdelmalek]

animal = 'cat'
out=sprintf('%s_mean',animal)