The graph doesn't disply

Sorry for repeating the question so many times. I try to display the graph, but the marked part does not appear. Can you help me?

clc; clear all; close all;

fun =@(t) (1/200).*t.^2+(1/500).*exp(-0.2.*t)+5;
dgraph = @(point, dfda, t) dfda*t + (fun(point)-dfda*point);


est_point=150; 
da=2; 

dfda_true=(1/100).*(150)+(-0.2./500).*exp(-0.2.*(150));
dfda_forward = (fun(est_point+da)-fun(est_point))./da; 
dfda_backforward=(fun(est_point)-fun(est_point-da))./da; 
dfda_center=(fun(est_point+da)-fun(est_point-da))./(2.*da)

a=-50:0.01:150;

figure(1)
plot(a,fun(a),'k'); hold on;
plot(a, dgraph(est_point,dfda_true,a),'b'); hold on; %dosen't work
plot(a, dgraph(est_point,dfda_center,a),'r'); hold on;

Answer 1

[Star Strider]

It actually does work. The problem is that the red line overplots it since it is plotted later, and hides the blue line. If you make the blue line wider (I set 'LineWidth',3 here) the blue line shows up.

Try this —

% clc; clear all; close all;

fun =@(t) (1/200).*t.^2+(1/500).*exp(-0.2.*t)+5;
dgraph = @(point, dfda, t) dfda*t + (fun(point)-dfda*point);


est_point=150; 
da=2; 

dfda_true=(1/100).*(150)+(-0.2./500).*exp(-0.2.*(150));
dfda_forward = (fun(est_point+da)-fun(est_point))./da; 
dfda_backforward=(fun(est_point)-fun(est_point-da))./da; 
dfda_center=(fun(est_point+da)-fun(est_point-da))./(2.*da);

a=-50:0.01:150;

figure(1)
plot(a,fun(a),'k'); hold on;
plot(a, dgraph(est_point,dfda_true,a),'b', 'LineWidth',3); hold on; %dosen't work
plot(a, dgraph(est_point,dfda_center,a),'r'); hold on;

.

[재훈]

Thank you so much for your help. have a good day! cheers:)

[Star Strider]

As always, my pleasure!