oblique shock wave relations

Given two of three variables, finds the third variable (Mach num, Beta, Theta) ...

Description

My program allows users to choose which variable they want to solve for. USES SYMBOLIC TOOLBOX CREATED IN MATLAB 6.1

they are asked to provide the other two.

this is the Beta-Theta-Mach relation for oblique shock waves.

note: solving for theta will result in a precise answer

while solving for Mach number or Beta relies on numerical approximations.

I output the error in the approximation

Algorithm used: most basic i.e. O(N^2)

• Required Products: Symbolic Math Toolbox
• MATLAB release: MATLAB 6.1 (R12.1)

[John D'Errico]

The author has put some effort into this code. At least it
is a function, not a script. Of course, given that it is a
function, why use input to provide the parameters? This
is why matlab allows the provision of input arguments to
a function. As a function, this code should also return the
value solved for.

It needs better documentation. A line or two that
describes the actual equation being solved would help,
to ensure that a user knows what is being solved. The
user gets very little information when they call help on
this function, and forcing the user to edit the code and
decipher what it does seems silly.

The actual solution is very inefficiently coded, using
brute force loops to creep up on a solution. Fzero would
have been a better solution. Best of course is the fairly
simple algebraic solution that would exist. For example,
the equation appears to be a quadratic polynomial in
Mach number, and transformable to a polynomial roots
problem in beta. While these last comments are purely
that of programming style, the approach chosen will
severely (negatively) impact the efficiency and accuracy of
the result.

I was pleased to see error checks done on the input
parameters.

[Author nick]

Thank you Mr. D'Errico,

I realize the methodology is probably the worst possible.

At the end of my semester (15 days from date of submission) I plan on rewriting the code and making it more useful.

I Will most definently use your advices and I completely forgot about FZERO. I am not sure how one can write a help file for a function. If you pass by this page again, or somebody else, please do offer more advices.

Sincerely,

Nick

[khashayar parsay]

 

[David Billingsley]

This is a great little program. Only face lifts would be a clarification of the user interface and function form for use inside of programs.