Question

Im writing a matlab script called vecadd that deals with vectors and is converting them between polar and rectangular coordinates. It is supposed to function based upon the following parameters:

vecadd adds two vectors and outputs the resultant vector.

vecadd(A,B) assumes A and B are both in rectangular form. The first element of each vector is the "x" component and the second element is the "y" component. The resultant is output in rectangular form.

vecadd(A,B,'p') assumes A and B are both in polar form. The first element of each vector is the magnitude and the second element is the angle in degrees. The resultant is output in polar form.

vecadd(A,B,'r') is equivalent to vecadd(A,B).

vecadd(A,B,'p','r') assumes A is in polar form and B is in rectangular form.  vecadd(A,B,'r','p') assumes A is in rectangular form and B is in polar form. The resultant is output in rectangular form.

vecadd(A,B,'p','r','p') outputs the resultant in polar form.

vecadd(A,B,'p','r','r') is equivalent to vecadd(A,B,'p','r').

[RES, FORM] = vecadd(A,B,'p','r','p') outputs the resultant and the format of the resultant vector ('polar' if the last input argument is 'p' and 'rectangular' if the last input argument is 'r').

I need some help getting on the right track. Anything will do. Thanks

Answer 1

Following is the code, hope this helps!

To add 2 vectors in polar form -

Code:  

% sample run

vecadd([2, 30], [1, 1], 'p', 'r', 'r')

function ans = vecadd(A, B, varargin)

if(nargin == 2)

ans = addR(A, B);

elseif(nargin ==3) % for 3 arguments

if(varargin{1} == 'p')

ans = addP(A, B);

else

ans = addR(A, B);

end

elseif(nargin == 4) % for 4 arguments

if(varargin{1} == 'p' && varargin{2} == 'r')

tmp = [A(1)*cosd(A(2)), A(1)*sind(A(2))];

ans = addR(tmp, B);

end

if(varargin{1} == 'r' && varargin{2} == 'p')

tmp = [B(1) *cosd(B(2)), B(1)*sind(B(2))];

ans = addR(A, tmp);

end

elseif(nargin == 5) % for 5 arguments

if(varargin{1} == 'p' && varargin{2} == 'r' && varargin{3} == 'p')

tmp = [A(1)*cosd(A(2)), A(1)*sind(A(2))];

x = addR(tmp, B);

ans = [(x(1)^2 + x(2)^2)^(1/2), arctan(x(2)/x(1))];

end

if(varargin{1} == 'p' && varargin{2} == 'r' && varargin{3} == 'r')

tmp = [A(1)*cosd(A(2)), A(1)*sind(A(2))];

ans = addR(tmp, B);

end

end

end

% helper function to add polar coordinates

function ans = addP(A, B)

r = (A(1)^2 + 2*A(1)*B(1)*cos(B(2)-A(2)) + B(1)^2)^(1/2);

alpha = A(2) + arctan((B(1)*cos(B(2)-A(2))) / (A(1) + B(1)*cos(B(2)-A(2))));

ans = [r, alpha];

end

% helper function to add rectangular coordinates

function ans = addR(A, B)

ans = [A(1) + B(1), A(2) + B(2)];

end

Sample run:

ans =

2.7321 2.0000

Code screenshots: