From cf767337fb89aae07e791189e785cb46c0e92c09 Mon Sep 17 00:00:00 2001 From: Vasil Zlatanov Date: Tue, 21 Feb 2017 19:49:46 +0000 Subject: finish exact solution --- coursework17/error_script.m | 19 +++++++++++++------ 1 file changed, 13 insertions(+), 6 deletions(-) diff --git a/coursework17/error_script.m b/coursework17/error_script.m index 2744ba9..08a42d2 100644 --- a/coursework17/error_script.m +++ b/coursework17/error_script.m @@ -6,21 +6,28 @@ data_points = 10000; % Go on for 8 time constants time_constant = L/R; -step = time_constant*8/data_points; +step = time_constant/data_points; T=150e-6; % 150us f = 1/T; +w_c = 2*pi*f; +A = 6; -Vin = @(t) 6*cos(2*pi*f*t); +Vin = @(t) A*cos(w_c*t); current_initial=0; -current_exact = @(t) -- -Vout_exact = @(t) -- +% e^m is the integratingn factor +m = 0.5/0.0015; + +% Solution is made by multiplying by integrating factor and +% then integrating both sides +current_exact = @(t) 3/(m^2+w_c^2)*(2*m*cos(w_c*t) + 2*w_c*sin(w_c*t)); +Vout_exact = @(t) Vin(t) - current_exact(t)*R; [time_array, Vout_array] = ralston(R, L, Vin, current_initial, step, data_points*step); for j=1:data_points - error_array(j) = Vout_exact(time_array(j)) - Vout_aray(j); + error_array(j) = Vout_exact(time_array(j)) - Vout_array(j); end -plot(log(time_array),log(error_array)); +loglog(time_array, error_array); -- cgit v1.2.3-54-g00ecf