Creating file names for save command

I have the following code:

   file_dir = 'C:\Users\mydir';
   datestamp=string(datetime('now','TimeZone','local','Format','yyyyMMdd_HHmmss'));
   file_name=strcat(file_dir,'sps_',datestamp,'.mat');
   save(file_name);

which returns the following error:

Error using save
Argument must contain a character vector.

Not sure how to fix this?

[Paul Nel]

Also tried this modification with out success. Same error although it does appear to generate a character vector..

file_name=sscanf(strcat(file_dir,'sps_',datestamp,'.mat'),'%s');

[Nagabhushan SN]

Same error:

save('temp.mat', data);
Error using save
Must be a string scalar or character vector.

Answer 1

[KSSV]

You have to put some data in the file....

file_dir = pwd;
datestamp=string(datetime('now','TimeZone','local','Format','yyyyMMdd_HHmmss'));
file_name=strcat(file_dir,filesep,'sps_',datestamp,'.mat');
data = rand(10,10) ;
save(file_name,'data');

[Paul Nel]

Unfortunately this is not the problem. As I see it the problem seems to be with the data type of the file name which I struggle to convert to a character vector.

[KSSV]

Yes it is a warning....

Try:

datestamp=char(datetime('now','TimeZone','local','Format','yyyyMMdd_HHmmss'));

instead of

datestamp=string(datetime('now','TimeZone','local','Format','yyyyMMdd_HHmmss'));

[Paul Nel]

Same result unfortunately

[KSSV]

How about replacing:

file_name=strcat(file_dir,filesep,'sps_',datestamp,'.mat');

with

file_name=char(strcat(file_dir,filesep,'sps_',datestamp,'.mat'));

[Jan]

Prefer fullfile to join path and file names.

Answer 2

[Thorsten]

   file_dir = 'C:\Users\mydir';
   datestamp=char(datetime('now','TimeZone','local','Format','yyyyMMdd_HHmmss'));
   file_name=strcat(file_dir,'sps_',datestamp,'.mat');

>> whos file_name
Name           Size            Bytes  Class    Attributes

file_name      1x37               74  char

This works for me.