MATLAB: Why am I getting this error, Subscript indices must either be real positive integers or logicals, when trying to set axis limits

axislogicalssubscript indices

I am plotting two volltage against time, I try to set the axis as follows,

axis([-0.1, 0.1 40 140])

but get this error; Subscript indices must either be real positive integers or logicals.

In the Command Window, type:

whos axis

I suspect you have a variable named ‘axis’ that is causing the error. The solution: rename the variable.

Try this

clear sin
r=10;
z=0:0.1:4*pi;
x=r*(z-sin(z))

Probably sin was used as a variable in a previous program

Did you define a variable called "set"? Check this by adding this before the failing command:

which set -all

Shadowing built-in functions in Matlab is a bad idea and leads to such bugs frequently.