MATLAB: Assigning a variable for matrices

matricesvariable

Hi,

I need to repeat the following calculation for S1, S2 upto S39 by changing the name S (1,2,…39). How can I assign a variable for S1, S2..S39 in the following code.

JanS1TRMM=mean(S1(1:31,:)); FebS1TRMM=mean(S1(32:59,:)); MarS1TRMM=mean(S1(60:90,:)); AprS1TRMM=mean(S1(91:120,:)); MayS1TRMM=mean(S1(121:151,:)); JunS1TRMM=mean(S1(152:181,:)); JulS1TRMM=mean(S1(182:212,:)); AugS1TRMM=mean(S1(213:243,:)); SepS1TRMM=mean(S1(244:273,:)); OctS1TRMM=mean(S1(274:304,:)); NovS1TRMM=mean(S1(305:334,:)); DecS1TRMM=mean(S1(335:365,:));

Any help is appreciated.

Thanks.

Best Answer

The recommendable thing is to get rid of the separate matrices S1...S39, replacing them instead by a single 3D array S(:,:,i).

This can be done as follows

for i=1:39
    S(:,:,i)=eval(['S' num2str(i)]);
end

Now, do manipulations in terms of S, as we discussed in your previous related thread.

Related Solutions

MATLAB: I want to find the determinant for 5.5 matrix

>> syms s1 s2 s3 s4 s5 s6 s7 s8 s9 s10
>> M = [0 -s1 -s2 -s3 -s4; s1 0 -s5 -s6 -s4; s2 s5 0 -s8 -s9; s3 s6 s8 0 -s10; s4 s7 s9 s10 0];
>> det(M)
ans =
s1*s4^2*s8^2 - s1*s4*s7*s8^2 - s2*s4^2*s6*s8 + s3*s4^2*s5*s8 - s3^2*s4*s5*s9 - s2^2*s4*s6*s10 + s3^2*s5*s7*s9 + s2^2*s6*s7*s10 + s2*s3*s4*s5*s10 + s2*s3*s4*s6*s9 + s1*s2*s4*s8*s10 - s1*s3*s4*s8*s9 - s2*s3*s5*s7*s10 - s2*s3*s6*s7*s9 + s2*s4*s6*s7*s8 - s3*s4*s5*s7*s8 - s1*s2*s7*s8*s10 + s1*s3*s7*s8*s9
>> simplify(ans)
ans =
(s4 - s7)*(s3*s5 - s2*s6 + s1*s8)*(s2*s10 - s3*s9 + s4*s8)

MATLAB: Is it possible to concatenate two structures in MATLAB 7.5 (R2007b)

If the structures have the same field names, you may contatenate them using [ ], HORZCAT or VERTCAT as follows:

S1 = struct('type', {'big1','little1'}, 'color', {'red1'}, 'x', {3 4})
S2 = struct('type', {'big2','little2'}, 'color', {'red2'}, 'x',{12,13})
% All of the following should work on these structs
[S1 S2]
[S1;S2]
horzcat(S1,S2)
cat(1,S1,S2)
cat(2,S1,S2)

The ability to concatenate two dissimilar structures (with different field names) is not available in MATLAB. For instance,

S1 = struct('type1', {'big1','little1'}, 'color1', {'red1'}, 'x1', {3 4})
S2 = struct('type2', {'big2','little2'}, 'color2', {'red2'}, 'x2',{12,13})

You may create a cell array of these structures,

S = {S1, S1}

Or, you may be able to do use the following approach to create a struct with a union of the field names. Any non-common fields will be set to [ ]

S = S1;
F = fieldnames(S2);
for i = length(S)+1:length(S)+length(S2)
      for j = 1:length(F)
          S(i).(F{j}) = S2.(F{j});
      end
end

Best Answer

Related Solutions

MATLAB: I want to find the determinant for 5.5 matrix

MATLAB: Is it possible to concatenate two structures in MATLAB 7.5 (R2007b)

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