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Error using <= Not enough input arguments

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sara07x x
sara07x x on 15 Jun 2021
Commented: Walter Roberson on 15 Jun 2021
This is my matlab code, it shows me error.
%computation of lambda - i curve
clear all
close all
%assign parameters
cm = 1e-2;
mm = 1e-2;
w=1*cm; %core width
Ws=5*cm; %slot width
ds=2*cm; %slot depth
d=5*cm; %depth
g=1*mm; %air gap
N=100; %number of turns
muo=4e-7*pi; %perm of free space
Bsat=1.3; %sat flux density
mur=1500; %init rel permeability
Am=w*d; %mag cross section
%start with flux linkage
lambda= linspace(0,0.08,1000);
%find flux, B, mu
phi=lambda/N;
B=phi/(w*d);
mu= muo *(mur-1)./(exp(10*(B-Bsat)).^2+1)+ muo;
%assign reluctance
Ric=(Ws+w)./(Am*mu);
Rbuc=(Ws+w)./(Am*mu);
Rg=g/(Am*muo);
Rluc= (ds+w/2)./(Am*mu);
%compute effective reluctance
Reff= Ric+Rbuc+2*Rg+2*Rluc;
%compute mmf and current
F=Reff.kphi;;
%find the characteristics
figure(1)
plot(i, lambda);
xlabel ('i,A');
ylabel ('\lambda, Vs');
grid on;
%show B-H characteristics
H=B/mu;
figure (2)
plot (H,B);
xlabel('H')
ylabel('B')
grid on;
Dot indexing is not supported for variables of this type.
I corrected it but still shows me :Dot indexing is not supported for variables of this type.

Answers (1)

Walter Roberson
Walter Roberson on 15 Jun 2021
Reff= Ric+Rbuc+2*Rg+2*Rluc;
That is a mathematical computation. The result is going to be numeric.
F=Reff.kphi;;
Reff is numeric, not a structure, and not an OOP object. It does not have any field or property named kphi
You do not have any variable named kphi
But perhaps what you intended was
F=Reff.*phi;;
  5 Comments
Walter Roberson
Walter Roberson on 15 Jun 2021
plot(i, lambda);
You have not assigned to i anywhere in the code, so i has its default value as a function that returns the scalar sqrt(-1)
lambda= linspace(0,0.08,1000);
lambda is your independent variable. Why are you trying to plot() it in the dependent-variable position of the plot() call?

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