How to use two outputs from function in another functions calculation

I need to figure out the angle between two vectors using functions. I Have figured out the dot product and the length of the vectors in two separate functions, and now bringing them together I can't seem to use both of the results from the length function as it only takes the one result. I am really new to MATLAB and pretty much have little idea what I'm doing, any help is greatly appreciated!

Here is the dot product code:

function c = myScalProd(a,b)
% This Matlab function calculates the scalar
% product of two vectors, a and b.
% Call syntax: y = myScalProd(a,b) or myScalProd(a,b)
% Input: two vectors of equal length, a and b
a= [2 4 1];
b=[-2 3 -2];
% Output: c, the value of the scalar product of a and b
n = length(a); % Get the length of the vector a
c=0; % Initialise the variable c
for i=1:n 
c = c + a(i)*b(i); 
end 
disp(['Scalar Product : ', num2str(c)])
end

and then the length code:

    function [d,g,w] = myLengthCalc()
  a=[2 4 1];
  b=[-2 3 -2];
  c=[4 1 6 2 3];
  d=(sqrt(sum(a.^2)));
  %displays the values for a
  disp(['Length of Vector a: ', num2str(d)]) 

g=(sqrt(sum(b.^2)));
disp(['Length of Vector b: ', num2str(g)]) 

w=(sqrt(sum(c.^2)));
disp(['Length of Vector c: ', num2str(w)]) 

end

Then Finally the part I am stuck with:

function thetaInDegrees = myAngleFind()

theta = myScalProd/myLengthCalc%;
thetaInDegrees= acosd(theta);
disp(['Angle Between: ', num2str(thetaInDegrees)])
end

Answer 1

[Jan]

I omit the unnecessary code (even the valuable comments - for clarity, leave them in the real code):

function c = myScalProd(a,b)
n = length(a);
c = 0;  % Initialise the variable c
for i = 1:n 
  c = c + a(i)*b(i); 
end 
end

function d = myLengthCalc(a)
d = sqrt(sum(a.^2));
end

function main
a = [2 4 1];
b = [-2 3 -2];

theta = myScalProd(a, b) / (myLengthCalc(a) * myLengthCalc(b))
thetaInDegrees = acosd(theta)
end

Now mxScalProd(a,b) gets the two variables as inputs. myLengthCalc(x) replies the Euclidean norm of the input vector.

By the way: acos is numerically instable: The rounding error gets huge for certain angles. asin has the same problem for other angles. So better use:

theta = atan2d(norm(cross(a,b)), dot(a,b))