Save and load in same file

Could please help me , i have several m1.mat,m2.mat,......mn.mat ; i add new row for m1.mat then save if by typing save m1 or save Workspace , then i repeat these steps for m2 , but when i return back to use m1 , i found it has old values before changing .

Answer 1

[Walter Roberson]

ds = load('m1.mat');
ds.m1(end+1,:)=newdata;
save('m1.mat','ds','-struct')

[lotus whit]

Thank you for your response, but i have this error: Error using save The -STRUCT option must be followed by the name of a scalar structure variable.

[Walter Roberson]

save('m1.mat', '-struct', 'ds')

[lotus whit]

Thanks it is working