Don't know how to put set of numbers in equation

Hello,

I'm new and I don't know how to put a set of numbers in one equation

fi = [0 3 13 23 33 34 43 53 63 73 83 90]

My equation:

N = a / (sqrt(1-e2 * sin(fi)^2))^3/2

Answer 1

[Les Beckham]

a = 1; % made up values - replace with the real ones
e2 = 0.1;
fi = [0 3 13 23 33 34 43 53 63 73 83 90];
N = a ./ (sqrt(1-e2 * sin(fi).^2)).^3/2;
%    ^                       ^    ^--- change these to element-wise operators
plot(fi, N)
grid on
xlabel 'fi'
ylabel 'N'

In case you meant 1e-2 instead of 1-e2:

N2 = a ./ (sqrt(1e-2 * sin(fi).^2)).^3/2;
figure
plot(fi, N2)
grid on
xlabel 'fi'
ylabel 'N2'

[Les Beckham]

Also, if you are just getting started with Matlab, I would highly recommend that you take a couple of hours to go through the free online tutorial: Matlab Onramp

[David]

I will check out the tutorial, thank you so much for help

[Les Beckham]

You are quite welcome. Please click the "Accept this answer" button on the answer that best helps with your question. You can also click the Vote button on any answer to show appreciation.

Answer 2

[Dyuman Joshi]

As you have not specified the values of a and e2, I am assuming random scalar values for them.

Use array operations - Array vs Matrix Operations

fi = [0 3 13 23 33 34 43 53 63 73 83 90]

%Random value between 0 and 1
a = rand;
e2 = rand;

%    vv                    vv   vv
N = a./(sqrt(1-e2 * sin(fi).^2)).^3/2

If e2 is a vector, then use element-wise multiplication for e2 and sin() as well.

Also, I suggest you take the free MATLAB Onramp tutorial to learn the essentials of MATLAB.

Answer 3

[Torsten]

Replace

N = a / (sqrt(1-e2 * sin(fi)^2))^3/2

by

N = a ./ (sqrt(1-e2 * sin(fi).^2)).^3/2

For an explanation, I suggest reading

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