Graphing as a function of Y

I want to use the function plot to plot the right-side of the equation f(y) = −2 + 5*y^2 − y*5 on the interval −2 ≤ y ≤ 2 (with y on horizontal axis).

The error message reads:

Error in assignment (line 1)

x = -2+5*y^2-y^5

How do I fix this?

x = -2+5*y^2-y^5
ylim([-2 -2])
plot (y,x)

[Bjorn Gustavsson]

If you have y as an array (either [n x 1] or [1 x n]) then matlab treats the operations * ^ as matrix-operations, for your case that means that y^2 and y^5 as matrix powers. You most likely want the element-wise power. In matlab that is written as y.^2 etc.

HTH

Answer 1

[rough93]

ylim([-2 -2])
x = -2+5.*y.^2-y.^5
plot (y,x)

As you are using a varying value of y in your x calculation, you need to include a . before your operations to make each calculation element-wise.

https://www.mathworks.com/help/matlab/matlab_prog/array-vs-matrix-operations.html

[Ankit]

small correction

ylim([-2 2])