From 213cb6e2aa88360c2847555f062fbe54b0b274db Mon Sep 17 00:00:00 2001 From: Vasil Zlatanov Date: Wed, 8 Mar 2017 16:57:52 +0000 Subject: clean up error_script --- coursework17/error_script.m | 91 ++++++++++++++++++++------------------------- 1 file changed, 41 insertions(+), 50 deletions(-) (limited to 'coursework17') diff --git a/coursework17/error_script.m b/coursework17/error_script.m index f17f234..83cf428 100644 --- a/coursework17/error_script.m +++ b/coursework17/error_script.m @@ -1,50 +1,41 @@ -% This script will carry out error analysis -R = 0.5; % 0.5Ohm -L = 0.0015; % 1.5mH - -data_points = 100000; -h_divisions = 1000; - -% Go on for a time constant -time_constant = L/R; -step = time_constant/data_points; - -T=150e-6; % 150us -f = 1/T; -w_c = 2*pi*f; -A = 6; - -Vin = @(t) A*cos(w_c*t); -current_initial=0; - -% e^m is the integratingn factor -% m = 0.5/0.0015; - -% Solution is made by multiplying by integrating factor and -% then integrating both sides - -A = 6*R/(R^2 + (w_c*L)^2); -B = 6*w_c*L/(R^2 + (w_c*L)^2); - -current_exact = @(t) A*cos(w_c*t) + B*sin(w_c*t) - A*exp((-R/L)*t); -%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; - -for k=1:h_divisions - - [time_array, Vout_array] = ralston(R, L, Vin, current_initial, step*k, data_points*step); - - for j=1:data_points/k - error_array(j) = Vout_exact(time_array(j)) - Vout_array(j); - % Vout_plot(j) = Vout_exact(time_array(j)); - end - - % plot(time_array, Vout_array); - % figure; - % plot(time_array, Vout_plot); - % - max_array(k) = max(error_array); - max_t(k) = k*step; -end - -loglog(max_t, max_array); +% This script will carry out error analysis +R = 0.5; % 0.5Ohm +L = 0.0015; % 1.5mH + +data_points = 100000; +h_divisions = 1000; + +% Go on for a time constant +time_constant = L/R; +step = time_constant/data_points; + +T=150e-6; % 150us +f = 1/T; +w = 2*pi*f; +A = 6; + +Vin = @(t) A*cos(w*t); +current_initial=0; + + +A = 6*R/(R^2 + (w*L)^2); +B = 6*w*L/(R^2 + (w*L)^2); + +current_exact = @(t) A*cos(w*t) + B*sin(w*t) - A*exp((-R/L)*t); +Vout_exact = @(t) Vin(t) - current_exact(t)*R; + +for k=1:h_divisions + + [time_array, Vout_array] = ralston(R, L, Vin, current_initial, step*k, data_points*step); + + for j=1:data_points/k + error_array(j) = Vout_exact(time_array(j)) - Vout_array(j); + end + max_array(k) = max(error_array); + max_t(k) = k*step; +end + +loglog(max_t, max_array); +title('Order of error') +xlabel('Time step size') +ylabel('Maximum error') -- cgit v1.2.3-54-g00ecf