I am getting this error "Index in position 1 is invalid. Array indices must be positive integers or logical values." Kindly help me clear this.

CODE:

Mt=0

m=0

for d=0.1:0.1:10.1

m=m+1

for i=a-2*(N-1)*wd-2*(N-1)*s:2*(wd+s):a-2*(N-N)*wd-2*(N-N)*s

for j=a-2*(N-1)*wd-2*(N-1)*s:2*(wd+s):a-2*(N-N)*wd-2*(N-N)*s

M(i,j)=0

r1=sqrt((x+i).^2+(y+i).^2+d.^2)

r2= sqrt((i-x).^2+(y+i).^2+d.^2)

r3=sqrt((i-x).^2+(y-i).^2+d.^2)

r4= sqrt((x+i).^2+(y-i).^2+d.^2)

C1= i+x

C4= -i-x

C2= i-x

C3= -i+x

d1= y+i

d2= y+i

d3= y-i

d4= y-i

angle=0

% Bz=((((u./(4.*pi)).*((((((-1).^1).*d1)./(r1.*(r1+((-1).^(1+1)).*C1)))-(C1./(r1.*(r1+d1))))+(((((-1).^2).*d2)./(r2.*(r2+(((-1).^(2+1))).*C2)))-(C2./(r2.*(r2+d2))))+(((((-1).^3).*d3)./(r3.*(r3+(((-1).^(3+1))).*C3)))-(C3./(r3.*(r3+d3))))+(((((-1).^4).*d4)./(r4.*(r4+((-1).^(4+1)).*C4)))-(C4./(r4.*(r4+d4)))))))/cos(angle))

M(i,j)=((((u./(4.*pi)).*((((((-1).^1).*d1)./(r1.*(r1+((-1).^(1+1)).*C1)))-(C1./(r1.*(r1+d1))))+(((((-1).^2).*d2)./(r2.*(r2+(((-1).^(2+1))).*C2)))-(C2./(r2.*(r2+d2))))+(((((-1).^3).*d3)./(r3.*(r3+(((-1).^(3+1))).*C3)))-(C3./(r3.*(r3+d3))))+(((((-1).^4).*d4)./(r4.*(r4+((-1).^(4+1)).*C4)))-(C4./(r4.*(r4+d4)))))))/cos(angle))

Mt=Mt+M(i,j)

end

end

Mtl(m)=Mt

end

Mtotal=Mtl(m)*10

plot(d,Mtotal,'x')

ERROR:

Index in position 1 is invalid. Array indices must be positive integers or logical values.

Error in MaloneAkila (line 70)

M(i,j)=0

[Swathi S]

Even after initializng M(i,j) after defining i and j, am getting the same error. Kindly guide.

Answer 1

[Torsten]

i and j are not defined at this line of your code ; they are first introduced one line later.

[Lenin Cruz]

You should probably also consider inititalizing your m variable in your second line.

[Swathi S]

Sir, I have initialized 'm' in my code but did not mentioned here.