Good morning team!
I am trying to prompt the user to input an equation but it seems input just calculates the equation. How do I retain x and y as a variable? The bolded and underlined is the part I am having trouble with.
syms e i r
display("Hello! Welcome to Matt Baron's numerical solver. Press enter to continue.")
pause
choice = input('Press e for Euler, i for Improved Euler, or r for RK4.');
if choice == e
step = input('What step size would you like?');
initcondx = input('What is the initial condition for x?');
initcondy = input('What is the initial condition for y?');
n=0;%start at 0
x=initcondx;%start at the initial condition
y=initcondy;%start at the initial condition
dfeq=input('What differential equation do you want approximated? i.e. .2 * x * y');
f=@(x,y) (dfeq);%the function to be evaluated
actual=@(x) (exp(.1 .* (x .^2) - .1));%the solved function
while x < 1.5%what value do you want it estimated to
x = (initcondx) + ((n) .* (step));
abs = actual(x) - y;
rel = (abs ./ actual(x)) .* 100;
[x y actual(x) abs rel]
y = (y) + ((step) .* f(x,y));
if x >= 1.5
break
end
n=n+1;
end
end
I have also tried;
f=@(x,y) (input('What differential equation do you want approximated? i.e. .2 * x * y'));%the function to be evaluated
Please point me in the right direction.
