MATLAB: Can’t i plug in a range of values into this equation

dimensionsMATLAB and Simulink Student Suitematrix

"equ" calculates interest growth, with r being the interest rate.

i want to plot a graph for the function "equ" from 0.001 to 0.1

r= linspace(0.001,0.1)

equ = 1000*((1+r)/r)*((1+r)^5 -1)

plot(r, equ)

i keep getting an error message:

"Error using ^ (line 51)

Incorrect dimensions for raising a matrix to a power.

Check that the matrix is square and the power is a

scalar. To perform elementwise matrix powers, use

'.^'."

when i do the alterations it suggests i get the wrong value.

what do i do?

Best Answer

The ‘equ’ function needs to use element-wise operations (using the dot operator):

r= linspace(0.001,0.1);
equ = 1000*((1+r)./r).*((1+r).^5 -1);
plot(r, equ)

See the documentation on Array vs. Matrix Operations for an extended discussion.

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that of course is not true, so the first section never evaluates.

You could put it in a loop, however this is more efficient:

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Try this:

syms A c r x z
A = sym(2);                                             % Substitute Correct Values


c = sym(3);                                             % Substitute Correct Values
t = sym(5);                                             % Substitute Correct Values
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