could you help me with this explanation?
1 Ansicht (letzte 30 Tage)
Ältere Kommentare anzeigen
isilay aydin
am 19 Mai 2020
Kommentiert: isilay aydin
am 19 Mai 2020
OverallEffectinevess = (MassFlowFunction*ConvectionCoolingEfficiency)/(1 + MassFlowFunction*ConvectionCoolingEfficiency);
MetalTemperature = (ExternalGasTemperature) - OverallEffectinevess*(ExternalGasTemperature-CoolantInletTemperature);
Error using *
Incorrect dimensions for matrix multiplication. Check that the number of columns in the first matrix matches the number of rows in the second matrix. To perform elementwise multiplication, use '.*'.
0 Kommentare
Akzeptierte Antwort
James Tursa
am 19 Mai 2020
Bearbeitet: James Tursa
am 19 Mai 2020
It's possible you just need to switch to element-wise operators. E.g.,
OverallEffectinevess = (MassFlowFunction.*ConvectionCoolingEfficiency)./(1 + MassFlowFunction.*ConvectionCoolingEfficiency);
MetalTemperature = (ExternalGasTemperature) - OverallEffectinevess.*(ExternalGasTemperature-CoolantInletTemperature);
What are the sizes of your variables?
3 Kommentare
Walter Roberson
am 19 Mai 2020
In MATLAB, C = A*B is algebraic matrix multiplication, also known as Inner Product.
C(I,J) = sum(A(I,:) .* B(:,J).')
In order for this to work, size(A,2) must be the same as size (B,1)
When you have A is a (10 x 1), B is a (10 x 1), then size(A,2) is 1, and size(B,1) is 10, and 1 is not equal to 10 so that is an error. You could have A*B' giving a 10 x 10 result, or you could have A'*B giving a 1 x 1 result, but not A*B .
If you want to multiple each element by its corresponding element, C(I,J) = A(I,J) * B(I,J) then you need the .* operator, MassFlowFunction.*ConvectionCoolingEfficiency not MassFlowFunction*ConvectionCoolingEfficiency
Weitere Antworten (0)
Siehe auch
Kategorien
Mehr zu Operating on Diagonal Matrices finden Sie in Help Center und File Exchange
Community Treasure Hunt
Find the treasures in MATLAB Central and discover how the community can help you!
Start Hunting!