ASSISTANCE ON RUNNING RANDOM VARIABLES IN A FUNCTION

I have a function "dydt=Q(Cin-y)-(Vs/H1)(1-Fd)CT-(K1/H1)(CD1-CD2)"

There are values that are constant (all but Q and Cin)

I want to start on that function but it is difficult since I'm not familiar with matlab if I can have a full written code I will be more than thankful

It is for learning purpose: video links will also be much appreciated

Answer 1

[hosein Javan]

I assumed that "y" must not be a constant since you have dy/dt. therefore I made it an input for the function

% define your constans here:
Vs =
H1 = 
Fd = 
CT = 
K1 =
H1 =
CD1 =
CD2 =

% function definition:
dydt = @(Q,Cin,y) Q.*(Cin-y)-(Vs/H1)*(1-Fd)*CT-(K1/H1)*(CD1-CD2)

if you want to call(calculate) the function for a specific set of inputs, simply use the syntax:

% define input arguments:
Q =
Cin = 
y = 

% call function
dydt(Q,Cin,y)

% notice that if you varaibles depend on time or any other varibles, they must be defined
% as functions too, like:
% Q = @(t) 1+t.^2

[CLEMENT CHIBOKO]

Thank You!

[hosein Javan]

you're welcome.

Answer 2

[Sulaymon Eshkabilov]

Hi,

Here is a nice tutorial that explains everything what you need for your exercise.

https://www.mathworks.com/help/matlab/matlab_prog/create-functions-in-files.html

[CLEMENT CHIBOKO]

Thank You

Answer 3

[John D'Errico]

Note that a random variable is a well defined term in mathematics and statistics, though much of the time when I see someone use that phrase, it is merely a way of describing a variable where they do not know the value, or where their professor will decide to call their code with some unknown value.

https://en.wikipedia.org/wiki/Random_variable

So, is this just a question about how to solve an ordinary differential equation, or how to solve a stochastic differential equation, thus an SDE?

https://en.wikipedia.org/wiki/Stochastic_differential_equation

https://ocw.mit.edu/courses/mathematics/18-s096-topics-in-mathematics-with-applications-in-finance-fall-2013/lecture-notes/MIT18_S096F13_lecnote21.pdf

https://www.math.nyu.edu/faculty/goodman/teaching/StochCalc2012/notes/Week9.pdf

[CLEMENT CHIBOKO]

Thank You