Inner matrix dimensions must agree

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b.m.n n 2016-11-14

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此问题的直接链接

https://ww2.mathworks.cn/matlabcentral/answers/312143-inner-matrix-dimensions-must-agree

评论： Alexandra Harkai 2016-11-16

Dear All Can anyone help me about this equation Qb=Qba*(1-(0.3251).^2)+4*(0.985)*(5.67*10.^-8)*(TS).^3*(TT); When i run it , I get this error Error using * Inner matrix dimensions must agree. where Qba [37*37 double] TS[37*1 double] TT [37*31 double] Thank All

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Answer 1

Jan 2016-11-14

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https://ww2.mathworks.cn/matlabcentral/answers/312143-inner-matrix-dimensions-must-agree#answer_243212

As you see, you want to multiply a [71x1] vector with a [37x31] matrix. This is mathematically not defined. What do you expect as output?

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Jan 2016-11-15

Of course it shows the same error for a [37x1] and [73x1] matrix. A valid Matrix multiplication would be: [1x37] and [37x1]. Please ask e.g. WikiPedia for the term "matrix multiplication".

b.m.n n 2016-11-16

Thank you so much Jan Simon

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Answer 2

Alexandra Harkai 2016-11-14

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此回答的直接链接

https://ww2.mathworks.cn/matlabcentral/answers/312143-inner-matrix-dimensions-must-agree#answer_243213

在 MATLAB Online 中打开

4*(0.985)*(5.67*10.^-8)*(TS).^3*(TT)

Here according to the operator precedence this happens:

(some_constant * (TS.^3)) * TT

which would require a matrix of 37x1 to be multiplied by a matrix of size 37x31, which is giving you the error.

It is possible the calculation is not formulated correctly in the first place.

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b.m.n n 2016-11-15

在 MATLAB Online 中打开

%long Wave Radition.(W/m2)(Qb)
%Qb=Qbo(1-cn^2)*4*epsilon*sigma*Ts.^3(TS-TA)
%==>Qba=(epsilon*sigma*(To^4))*(0.39-0.05*(Sqrt(P)));
% epsilon=0.985;
% sigma=(5.67*10^-8 );%Wm^(-2) K^(-4) the Stefan–Boltzmann constant
% The Constants a and b(0.39-0.05)
%Ts=sea surface temperature[K]
%Ta=air temperature[K]
%___________________________
%Desemper_Temp
Ts=TEMP_DEC_S;%[C]         [ 37x1 ]
Ta=TempDryAvg(784-2:814-2);%[c] [31x1]
%K=C+273.15
TS=Ts+273.15; %[37x1]
TA=Ta+273.15; %[31x1]
%___________________________
%Vapor Pressure of Water calculator Formula
%P=10^(A_B/(C+T))
%Where:
%P: Vapor Pressure of Water
%T: Water Temperature, in Celsius
%A,B,C: Antoine Constants for Water.
%When water temperature in the range of 1 - 100 Celsius
A=8.07131;
B=1730.63;
C= 233.426;
ea=10.^(A-B/(C+Ts)); %[1x37]
%==>Qba=(epsilon*sigma*(To^4))*(0.39-0.05*(Sqrt(ea)));
Qba=(0.985*5.67*10.^-8*(TS.^4))*(0.39-0.05*(sqrt(ea)));%[37x37]
Qb=Qba*(1-(0.3251).^2)+4*(0.985)*(5.67*10.^-8)*(TS.^3)*(TA-TS);

%%%%%%%%%%%%%%%%%%%

   % to get seam size (TA)
  Taa=ones(37,1)*nan;%a new matrix
s=37;%number of  ROW
for i=1:s
       TA(i,:)=Taa(i,:)+1;
  end

b.m.n n 2016-11-16

Thank you so much..Alexandra ..I want to get same size for TA and TS .But i don't now how .

Alexandra Harkai 2016-11-16

It is not exactly clear what you are tying to achieve. Depending on what the vectors represent, the operation may not even make sense. Are you sure this is the computation you need?

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