error while using ezplot

I am trying to plot this equation given by my professor:

M=ezplot((1654/21)*(atan(2*(t-45)/21)+atan(30/7)),[1,90])

and this error is coming up:

Error using ezplot (line 69) Input must be a string expression, function name, function handle, or INLINE object.

What does this mean and how can I get a graph?

Answer 1

[Star Strider]

Add ‘@(t)’ to create an anonymous function from your expression, and it works:

M = ezplot(@(t) (1654/21)*(atan(2*(t-45)/21)+atan(30/7)),[1,90])

See the section on ‘Anonymous Functions’ in Function Basics for details.