I have a differential equation of the form:
xs'' = rhs * theta
to solve in Simulink, where xs and theta are variables and rhs is a numerical constant. So far, I've got this:
but it's incomplete and I feel it is wrong. How can I simulate this equation in Simulink?
Regards
This works as expected:
Thanks to #Ander Biguri!
Related
How can I show that y(t)=Yo/Yo+(1-Yo)e^-at is the solution of the differential equation dy/dt=ay(1-y) using MATLAB. What function should I use?
if you want to simulate the results use the ode's family
https://www.mathworks.com/help/matlab/ref/ode45.html
else you can define your equation in syms and use diff
https://www.mathworks.com/help/symbolic/diff.html
other wise you can solve it numerically
I am having trouble solving a system of equations. I have three equations with a known solution and three unknowns in each equation. However, when I use the solve function in MATLAB, it returns with the error that I have six equations and three variables.
A snippet of my code:
syms V0 T0 X0
A=(g*X0/(2*V0^2*cos(T0)^2)-tan(T0))==a;
B=(tan(T0)-g*X0/(V0^2*cos(T0)^2))==b;
C=(-g/(2*V0^2*cos(T0)^2))==c;
soln=solve([A,B,C],[V0,T0,X0]);
I have already calculated scalar values for a, b, and c. g is a constant.
I am not sure why it is returning that I have six equations.
V0^2 means its a quadratic equation. You could solve for V0^2 as a variable. Set V0^2 = J0 and solve for J0 instead.
soln=solve([A,B,C],[J0,T0,X0]);
Then its three linear equations with three variables.
Once you get value of J0, then you need to solve for V0^2 = J0.
Help. I am trying to solve this system of nonlinear equations in MATLAB for a homework assignment. I have tried wolfram alpha and this online equation solver, and neither of them work.
I have tried my graphing calculator and it keeps saying non algebraic variable or expression.
These are my two equations in two unknowns:
.75*(1100)= x*10^(6.82485-943.453/(T+239.711))
25*1100=(1-x)*10^(6.88555-1175.817/(T+224.887)
I don't quite understand how to use MATLAB to solve this system. Please help.
You want the function fsolve in Matlab. Define a function myfun that returns [0,0] at the solution, then run fsolve(myfun,x0). x0 is a guess for the solution.
Define myfun:
function F = myfun(x)
F = [<put modified eqt1 here>;
<put modified eqt2 here>;];
Save it. Then solve:
x0 = [1,1];
options = optimoptions('fsolve','Display','iter');
[x,fval] = fsolve(#myfun,x0,options) % Call solver
I have to analyze 802.11 saturation throughput using matlab, and here is my problem. I'm trying to solve parametric equations below (parameters are m,W,a) using solve function and i get
Warning: Explicit solution could not be found
How could I solve above equations using matlab?
I guess you were trying to find an analytical solution for tau and p using symbolic math. Unless you're really lucky with your parameters (e.g. m=1), there won't be an analytical solution.
If you're interested in numerical values for tau and p, I suggest you manually substitue p in the first equation, and then solve an equation of the form tau-bigFraction=0 using, e.g. fzero.
Here's how you'd use fzero to solve a simple equation kx=exp(-x), with k being a parameter.
k = 5; %# set a value for k
x = fzero(#(x)k*x-exp(-x),0); %# initial guess: x=0
I can't solve this differential equation by ode45 beacause it has sigularity.
xy"=3xcos(x)+sin(x) ; x(0)=0 , x'(0)=0
can you help me to write ode45 function?
You can use the sinc(x) function, which is defined as sin(π*x)/(π*x), except at x=0 where its value is 1. So, you can rewrite your ODE as:
y'' = 3*cos(x) + sinc(x/π)
which ode45 shouldn't have any trouble solving.