accept exerercise 3 form Alex

2 files changed, 39 insertions, 0 deletions

diff --git a/coursework17/RK4second.m b/coursework17/RK4second.m
new file mode 100644
index 0000000..7388c27
--- /dev/null
+++ b/coursework17/RK4second.m
@@ -0,0 +1,12 @@
+function [x, y] = RK4second(t,x,y,h,g,f)

+k1x = h*g(t, x,y);

+k1y = h*f(t, x,y);

+k2x = h*g(t+h/3, x+k1x/3, y+k1y/3);%if it doesnt work try k1y after y

+k2y = h*f(t+h/3, x+k1x/3, y+k1y/3);

+k3x = h*g(t+2*h/3, x-k1x/3+k2x, y-k1y/3+k2y);

+k3y = h*f(t+2*h/3, x-k1x/3+k2x, y-k1y/3+k2y);

+k4x = h*g(t+h, x+k1x-k2x+k3x, y+k1y-k2y+k3y);

+k4y = h*f(t+h, x+k1x-k2x+k3x, y+k1y-k2y+k3y);

+x = x+(1/8)*(k1x+3*k2x+3*k3x+k4x);

+y = y+(1/8)*(k1y+3*k2y+3*k3y+k4y);

+end

diff --git a/coursework17/RLC_script.m b/coursework17/RLC_script.m
new file mode 100644
index 0000000..42f0344
--- /dev/null
+++ b/coursework17/RLC_script.m
@@ -0,0 +1,27 @@
+h = 1e-4;

+R = 280;

+C = 4*10^(-6);

+L = 600*10^(-3);

+t0 = 0;

+tf = 0.04;

+N = round((tf-t0)/h);

+

+y = zeros(1, N);

+x = zeros(1, N);

+t = zeros(1, N);

+n = zeros(1, N);

+

+

+t(1) = t0;

+Vout = zeros(1, N);

+x(1) = 500*10^(-9);

+y(1) = 0;

+Vin = @(a)5;

+g = @(t,x,y) y;

+f = @(t,x,y)(Vin(t) - x/C - R*y)/L;

+for i = 1:N-1

+    [x(i+1), y(i+1)] = RK4second(t(i),x(i),y(i),h,g,f);

+    t(i+1) = t(i) + h;

+    Vout(i) = R*y(i);

+end

+plot(Vout);