Error: Array indices must be positive integers or logical values.

Here is my code:

clc;clear;
t=[0:0.5:60];
h(t)=2.03*t.^2-0.0013*t.^4+0.000034*t.^4.751;
plot(t, h(t));
xlabel('Time');
ylabel('Height(m)');

But I get this error when I try to evaluate:

Array indices must be positive integers or logical values.

I need 100 values from 0 to 60 for my graph.

Thank you!

Answer 1

[Walter Roberson]

Please read https://www.mathworks.com/matlabcentral/answers/395816-why-do-i-get-array-indices-must-be-positive-integers-or-logical-values-error-when-using-angle-fu#comment_882605

Answer 2

[Bjorn Gustavsson]

Matlab has the convention that arrays-indexes starts from 1. Arrays have to be indexed with integers.

You can solve your problem in 2 ways. Either you simply assign the values you want directly to the array:

h = 2.03*t.^2 - 0.0013*t.^4 + 0.000034*t.^4.751;

or you define a function for h:

h = @(t) 2.03*t.^2 - 0.0013*t.^4 + 0.000034*t.^4.751;

In the first case you simply plot the 2 arrays:

plot(t,h)

In the second case you plot the function:

plot(t,h(t))

It seems you're very new to matlab - therefore I recommend you to look through the on-ramp material to get up to speed as fast as possible.

HTH