Storing data with 2 forloops?

When I try to extract RASI from my data:

for welke_pp=1:5
...
for i_testen=1:5
...
RASI(welke_pp,i_testen) = data_sts(welke_pp,i_testen).VideoSignals(:, strcmp('RASI', data_sts(welke_pp,i_testen).VideoSignals_headers)); %try to extract data, RASI
...
end
end

The following error occurs 'Subscripted assignment dimension mismatch.' and I don't understand why... Help?

Answer 1

[Geoff Hayes]

Sam - what are the dimensions of your RASI and data_sts matrices or cell arrays? What are you attempting to do with

 VideoSignals(:, strcmp('RASI', data_sts(welke_pp,i_testen).VideoSignals_headers))

In the above, if the string at data_sts(welke_pp,i_testen).VideoSignals_headers is not RASI, then the strcmp returns a zero in which case you will be trying to access

 VideoSignals(:,0);

which will generate an error (though not the one that you are observing).

Your error, Subscripted assignment dimension mismatch, typically means that you are attempting to assign too much (or too little) data. In your case, if RASI is a matrix, then

 RASI(welke_pp,i_testen)

is a single element within that matrix, and

 data_sts(welke_pp,i_testen).VideoSignals(:,1)

may be a column vector of data...and so you are attempting to assign a column vector to a single element within RASI.

Put a breakpoint at this assignment and run your code. When the debugger pauses at this line, look at what is being assigned and where you are assigning it to, and ask yourself if the assignment makes sense.

[Sam]

data_sts is a 5x5struct (see attachment). Each struct contains 6 data-files (see attachment). VideoSignals is a 3D matrix. I want to extract RASI (which is a column vector with variable length). If I type:

RASI{1,i_testen} = data_sts(welke_pp,i_testen).VideoSignals(:, strcmp('RASI', data_sts(welke_pp,i_testen).VideoSignals_headers)); %try to extract data, RASI

I can extract RASI but just for the first subject until it reaches i_testen = 5. Maybe my if-statement has something to do with it?

for welke_pp=1:5
...
for i_testen=1:5
  if ~( ((i_testen == 4) && (welke_pp == 1)) || ((i_testen == 4) && (welke_pp == 3)) || ((i_testen == 4) && (welke_pp == 4)) || ((i_testen == 4) && (welke_pp == 5)) );
...
RASI{1,i_testen} = data_sts(welke_pp,i_testen).VideoSignals(:, strcmp('RASI', data_sts(welke_pp,i_testen).VideoSignals_headers)); %try to extract data, RASI
...
end
end

[per isakson]

"(see attachment)" &nbsp There is no attachment

[Sam]

Found it. Thanks!