save variables in .mat files with desired name.

I have a function where I do my calculation to get A cell or array. Now I want to save this array in a .mat file but I want to change the variable name.

myData = [1 2 3 4 5 6 7 8 9]; %data from my calculation
save Data.mat myData

This saves my data in Data.mat file but with variable name myData. Now I want to save values of myData in .mat file but I want to save the value under a variable name given via input function. Something like:

myData = [1 2 3 4 5 6 7 8 9]; %data from my calculation
newName = input('I want to save the variable under the name:', 's');
save Data.mat ???

I hope that make sense

Thanks

Answer 1

[Jan]

myData = [1 2 3 4 5 6 7 8 9]; %data from my calculation
newName = input('I want to save the variable under the name:', 's');
S.(newName) = myData;
save('Data.mat', '-struct', 'S')  % EDITED

[Sunil Shahi]

thank you that worked only had to change order like this save('Data.mat', '-struct','S')

[Richard Crozier]

Does this solution result in making a copy of the data in memory, or is matlab smart enough to avoid this?

[John Paden]

No it is does not copy. Matlab uses copy-on-write and does not make a copy unless changes are made to one of the variables. You can do any number of copies between variables, structure fields, or cell array elements and only a pointer to the original data is used to store the "copy". When any one of the copies is written to, the copy that is written to will be fully copied at that point, but all the other copies that are not written to will continue to point back to the original copy. For example, the following code only stores a single copy. The first line of code actually uses memory to store the variable. The next four lines are just pointers back to the original data.

>> test = zeros(250e6,1);
>> s.data = test;
>> C{1} = test;
>> C{2} = test;
>> C{3} = s.data;

Answer 2

[Bruno]

Maybe, a simples way to answer that need is to do the following:

fname = sprintf('Data.mat', myData); 
save(fname)

Hope it can help others.

[Eleanna Kritikaki]

Damn right it did. Thanks man

Answer 3

[Azzi Abdelmalek]

myData = [1 2 3 4 5 6 7  9]; 
newName = input('I want to save the variable under the name:', 's');
assignin('base',newName,myData)
save('Data.mat',newName)

[Sunil Shahi]

I tried that. However since I was calling this inside a function I used 'caller' instead of 'base' but my .m function file has nested functions in it. I get this error:

Attempt to add "<var_name>" to a static workspace. See MATLAB Programming, Restrictions on Assigning to Variables for details.

[Jan]

Avoid to create variables dynamically by assignin or eval. There is always a better solution.

[Azzi Abdelmalek]

myData = [1 2 3 4 5 6 7 8 9]; %data from my calculation
newName = input('I want to save the variable under the name:', 's');
a.(newName)=myData;
save('Data.mat','-struct','a',newName)