'Matrix dimensions must agree' error

1 view (last 30 days)
IOANNIS KORACHAIS
IOANNIS KORACHAIS on 14 Nov 2020
Answered: Star Strider on 14 Nov 2020
i have this code and it says that the matrix dimensions must agree. What am i doing wrong? I'm really new in matlab.
Re = 190000:10000:290000;
Pr = 3.66:0.5:5.66;
Pr = double(Pr);
Nu = [(0.3+0.62.*Re.^(1/2).*Pr.^(1/3))/(1+(0.4/Pr).^(2/3)).^(1/4)].*(1+(Re/282000))
  1 Comment
IOANNIS KORACHAIS
IOANNIS KORACHAIS on 14 Nov 2020
The 'Pr = double(Pr)' is a mistake i made, i forgot to erase it for this post sorry

Sign in to comment.

Answers (1)

Star Strider
Star Strider on 14 Nov 2020
Vectorise all multiplication, division and exponentiation operations, and it works:
Re = 190000:10000:290000;
Pr = 3.66:0.5:5.66;
[Rem,Prm] = ndgrid(Re, Pr);
Nu = @(Re,Pr) ((0.3+0.62.*Re.^(1/2).*Pr.^(1/3))./(1+(0.4./Pr).^(2/3)).^(1/4)).*(1+(Re/282000))
figure
surf(Rem, Prm, Nu(Rem,Prm))
grid on
.

Categories

Find more on Multidimensional Arrays in Help Center and File Exchange

Community Treasure Hunt

Find the treasures in MATLAB Central and discover how the community can help you!

Start Hunting!