merge multiple 4-D double

hello, i am using delft3d for my hydrodynamics simulations. Delft3D exports to .mat version 7 files.

so my quiestion is, how can i join this 4 variables into one for each filename?

Name                   Size                     Bytes  Class       Attributes

Zp1                 2500x71x42x6            357840000  double                
Zp2                 2500x71x42x6            357840000  double                
Zp3                 2500x71x42x6            357840000  double                
Zp4                 1284x71x42x6            183786624  double                
a4_salin_6c_p1      2500x71x42x6            357840000  double                
a4_salin_6c_p2      2500x71x42x6            357840000  double                
a4_salin_6c_p3      2500x71x42x6            357840000  double                
a4_salin_6c_p4      1284x71x42x6            183786624  double                
dt_p1               2500x1                      40001  datetime              
dt_p2               2500x1                      40001  datetime              
dt_p3               2500x1                      40001  datetime              
dt_p4               1284x1                      20545  datetime              
jd_p1               2500x1                      20000  double                
jd_p2               2500x1                      20000  double                
jd_p3               2500x1                      20000  double                
jd_p4               1284x1                      10272  double

any ideas?

please help, since its very time consuming to manage multiple files for every single variable that i have to used.

[Rik]

Do you have control over those names? Because you shouldn't use numbered variables if you can avoid it.

How should the matrices be joined? Should Zp be 2500x71x42x6x4? 2500x71x42x24? 8784x71x42x6?

Anyway, the cat function should do what you need. With that function you can specify the dimension along which you want to concatenate variables.

[roberto ivan perez luna]

ok, i'll change the numers ;)

i need them to be like this:

8748x71x42x6 for "Zp" and a4_salin_6c

and for the dates in gregorian and julian, like this:

8784x1 for dt and jd

ok, so i look up for "cat" function, and thats it?

[Rik]

That should be it.

Answer 1

[Guillaume]

Numbered variables are always a bad idea. Much better would be to just have one variable (a cell array in your case) containing all the arrays in these numbered variables. But perhaps you have no control over that from your export function.

So, first step would be to create that container:

numvars = 4;  %adjust as required
varprefix = 'Zp';  %adjust as required

container = cell(1, numvars);  %container for the variables
for varidx = 1:numvars
  eval(sprintf('container{%2$d} = %1$s%2$d', varprefix, varidx))
end

Once that is done, it is trivial to vertically concatenate the matrices in the container into one matrix with cat or vertcat as per Rik's comment:

Zp = vertcat(container{:});  %That's all that is required

Note that we're using eval here to fix the mess that is the numbered variables. See matlab's documentation for why eval and numbered variables are bad.