saving multiple fields of structure as separate mat files and creating directory non-existing directories - matlab

Question

There are two parts of my query
1) How to save different fields of structures as separate files(each file containing only named field of structure )?
2) Forcing save command to create directories in the save path when intermediate directories do not exist?
For first part:
data.a.name='a';
data.a.age=5;
data.b.name='b';
data.b.age=6;
data.c.name='c';
data.c.age=7;
fields=fieldnames(data);
for i=1:length(fields)
save(['E:\data\' fields{i} '.mat'],'-struct','data');
end
I want to save each field of struct data as a separate .mat file. So that after executing the loop, I should have 3 files inside E:\data viz. a.mat,b.mat and c.mat and a.mat contains only data of field 'a', b.mat contains only data of field 'b' and so on.
When I exeucte the above code, I get three files in my directory but each file contains identical content of all three variables a, b and c, instead of individual variables in each file.
Following command does not work:
for i=1:length(fields)
save(['E:\data\' fields{i} '.mat'],'-struct',['data.' fields{i} ]);
end
Error using save
The argument to -STRUCT must be the name of a scalar structure variable.
Is there some way to use save command to achieve my purpose without having to create temporary vaiables for saving each field?
For Second Part:
I have large number of files which need to stored in a directory structure. I want following to work.
test='abcdefgh';
save(['E:\data\' test(1:2) '\' test(3:4) '\' test(5:6) '\result.mat'])
But it showing following error
Error using save
Cannot create 'result.mat' because 'E:\data\ab\cd\ef' does not exist.
If any intermediate directory are not present, then they should be created by save command. I can get this part to work by checking if directory is present or not using exist command and then create directory using mkdir. I am wondering if there is some way to force save command to do the work using some argument I am not aware of.

Answer 1

Your field input argument to save is wrong. Per the documentation, the format is:
'-struct',structName,field1,...,fieldN
So the appropriate save syntax is:
data.a.name='a';
data.a.age=5;
data.b.name='b';
data.b.age=6;
data.c.name='c';
data.c.age=7;
fields = fieldnames(data);
for ii = 1:length(fields)
save(['E:\data\' fields{ii} '.mat'], '-struct', 'data', fields{ii});
end
And no, you cannot force save to generate the intermediate directories. Check for the existence of the save path first and create it if necessary.