Why do I get "Array indices must be positive integers or logical values" error?

lc= 0.03

b=0.013

Rc= 0.0275

theta1= 0:15:360

theta2=theta1*pi/180

x=lc/2;

y=((Rc^2)*(theta2))

z=((b^2)*0.5)*(sin((theta1).*2))

r=b*(sin(theta1))

u1=Rc^2

u2=r.^2

u=r.*(((u1)-(u2)).^1/2)

rr=Rc^2*atan(r/u)

Vc=x(y+z-u-rr)

Why can't solve? Can someone help me?

Answer 1

[Arif Hoq]

try this:

lc= 0.03;
b=0.013;
Rc= 0.0275;
theta1= 0:15:360;
theta2=theta1*pi/180;
x=lc/2;
y=((Rc^2)*(theta2));
z=((b^2)*0.5)*(sin((theta1).*2));
r=b*(sin(theta1));
u1=Rc^2;
u2=r.^2;
u=r.*(((u1)-(u2)).^1/2);
rr=Rc^2*atan(r/u);
Vc=x*(y+z-u-rr)

Vc = 1×25

1.0e-04 * -0.1782 -0.1614 -0.1220 -0.0783 -0.0518 -0.0384 -0.0107 0.0362 0.0710 0.0868 0.1066 0.1463 0.1909 0.2132 0.2268 0.2592 0.3043 0.3381 0.3521 0.3732 0.4169 0.4576 0.4786 0.4937 0.5271

Answer 2

[Askic V]

You asked why, and the answer is because of this line:

Vc=x(y+z-u-rr)

here, x is considered an array and y+z-u-rr is an index. basically you're trying to access an element of the array throught its index. Indices should be positive integers or logical values and not numbers with decimal points.

So this is probably a typo and Arif corrected this line to be:

Vc=x*(y+z-u-rr)