MATLAB: Am i receiving “Array indices must be positive integers or logical values.” error

Question

I keep getting some sort of indexing error when running my code, but cannot find the error. Please help.

x0 = 0;

v0 = 2;

wn = 8;

ez = 0.07;

wd = wn * sqrt(1-ez^(2));

t = linspace (0, 10, 937);

x(t) = exp(-ez.*wn.*t) .* (x0.*cos(wd.*t) + ((v0+(ez.*wn.*x0))./wd)…

    .* sin(wd.*t))

Answer 1

The problem:

t = linspace (0, 10, 937);
x(t) = exp(-ez.*wn.*t) .* (x0.*cos(wd.*t) + ((v0+(ez.*wn.*x0))./wd)...
      .* sin(wd.*t))

First, ‘t’ begins with a 0, and the other values are almost all decimal fractions, not integers. Positive integers are integers greater than 0.

The solution is to delete the subscript.

This works:

x = exp(-ez.*wn.*t) .* (x0.*cos(wd.*t) + ((v0+(ez.*wn.*x0))./wd)...
      .* sin(wd.*t));