The figure in my code does not appear

The code i am working on is the euler's method for BVP. The code runs without an error but the plot window appears with no graph in it, why does this happen? and how can i fix it?

Answer 1

[KSSV]

USe marker. As you are plottint point by point.

clc; close ;clear all

A = 2 ;
Kc = 1 ;
t1 = 0.1 ;
delta_h = 0 ;
h = 0.1 ;
z = 2 ;

figure
hold on
for t = 0:h:10
    delta_h_next = delta_h + (z * h) ;
    z_next = z - ((Kc/A)*z+((Kc/(A*t1)*delta_h))*h) ;
    delta_h = delta_h_next ;
    z = z_next ;
     fprintf('%5.4f   %11.8f \n', t, delta_h);
    plot(delta_h,t,'*-r')
end

0.0000    0.20000000 
0.1000    0.30000000 
0.2000    0.34000000 
0.3000    0.34500000 
0.4000    0.33050000 
0.5000    0.30600000 
0.6000    0.27722500 
0.7000    0.24753750 
0.8000    0.21883250 
0.9000    0.19210313 
1.0000    0.16779681 
1.1000    0.14603850 
1.2000    0.12676950 
1.3000    0.10983308 
1.4000    0.09502639 
1.5000    0.08213140 
1.6000    0.07093258 
1.7000    0.06122660 
1.8000    0.05282698 
1.9000    0.04556584 
2.0000    0.03929392 
2.1000    0.03387967 
2.2000    0.02920785 
2.3000    0.02517795 
2.4000    0.02170262 
2.5000    0.01870605 
2.6000    0.01612263 
2.7000    0.01389562 
2.8000    0.01197599 
2.9000    0.01032139 
3.0000    0.00889529 
3.1000    0.00766617 
3.2000    0.00660685 
3.3000    0.00569388 
3.4000    0.00490705 
3.5000    0.00422894 
3.6000    0.00364453 
3.7000    0.00314088 
3.8000    0.00270683 
3.9000    0.00233276 
4.0000    0.00201039 
4.1000    0.00173256 
4.2000    0.00149313 
4.3000    0.00128678 
4.4000    0.00110895 
4.5000    0.00095570 
4.6000    0.00082363 
4.7000    0.00070980 
4.8000    0.00061171 
4.9000    0.00052718 
5.0000    0.00045432 
5.1000    0.00039154 
5.2000    0.00033743 
5.3000    0.00029080 
5.4000    0.00025061 
5.5000    0.00021598 
5.6000    0.00018613 
5.7000    0.00016041 
5.8000    0.00013824 
5.9000    0.00011913 
6.0000    0.00010267 
6.1000    0.00008848 
6.2000    0.00007625 
6.3000    0.00006572 
6.4000    0.00005663 
6.5000    0.00004881 
6.6000    0.00004206 
6.7000    0.00003625 
6.8000    0.00003124 
6.9000    0.00002692 
7.0000    0.00002320 
7.1000    0.00002000 
7.2000    0.00001723 
7.3000    0.00001485 
7.4000    0.00001280 
7.5000    0.00001103 
7.6000    0.00000951 
7.7000    0.00000819 
7.8000    0.00000706 
7.9000    0.00000608 
8.0000    0.00000524 
8.1000    0.00000452 
8.2000    0.00000389 
8.3000    0.00000336 
8.4000    0.00000289 
8.5000    0.00000249 
8.6000    0.00000215 
8.7000    0.00000185 
8.8000    0.00000160 
8.9000    0.00000137 
9.0000    0.00000118 
9.1000    0.00000102 
9.2000    0.00000088 
9.3000    0.00000076 
9.4000    0.00000065 
9.5000    0.00000056 
9.6000    0.00000049 
9.7000    0.00000042 
9.8000    0.00000036 
9.9000    0.00000031 
10.0000    0.00000027 

[Mohamed T. Adam]

Thank you so much

Answer 2

[KSSV]

Also you can save them into an array and plot after the loop:

A = 2 ;
Kc = 1 ;
t1 = 0.1 ;
delta_h = 0 ;
h = 0.1 ;
z = 2 ;
count = 0 ;
x = zeros([],1) ;
y = zeros([],1) ; 
for t = 0:h:10
    count = count+1 ; 
    delta_h_next = delta_h + (z * h) ;
    z_next = z - ((Kc/A)*z+((Kc/(A*t1)*delta_h))*h) ;
    delta_h = delta_h_next ;
    z = z_next ;
    fprintf('%5.4f   %11.8f \n', t, delta_h);
    x(count) = delta_h ;
    y(count) = t ; 
end

0.0000    0.20000000 
0.1000    0.30000000 
0.2000    0.34000000 
0.3000    0.34500000 
0.4000    0.33050000 
0.5000    0.30600000 
0.6000    0.27722500 
0.7000    0.24753750 
0.8000    0.21883250 
0.9000    0.19210313 
1.0000    0.16779681 
1.1000    0.14603850 
1.2000    0.12676950 
1.3000    0.10983308 
1.4000    0.09502639 
1.5000    0.08213140 
1.6000    0.07093258 
1.7000    0.06122660 
1.8000    0.05282698 
1.9000    0.04556584 
2.0000    0.03929392 
2.1000    0.03387967 
2.2000    0.02920785 
2.3000    0.02517795 
2.4000    0.02170262 
2.5000    0.01870605 
2.6000    0.01612263 
2.7000    0.01389562 
2.8000    0.01197599 
2.9000    0.01032139 
3.0000    0.00889529 
3.1000    0.00766617 
3.2000    0.00660685 
3.3000    0.00569388 
3.4000    0.00490705 
3.5000    0.00422894 
3.6000    0.00364453 
3.7000    0.00314088 
3.8000    0.00270683 
3.9000    0.00233276 
4.0000    0.00201039 
4.1000    0.00173256 
4.2000    0.00149313 
4.3000    0.00128678 
4.4000    0.00110895 
4.5000    0.00095570 
4.6000    0.00082363 
4.7000    0.00070980 
4.8000    0.00061171 
4.9000    0.00052718 
5.0000    0.00045432 
5.1000    0.00039154 
5.2000    0.00033743 
5.3000    0.00029080 
5.4000    0.00025061 
5.5000    0.00021598 
5.6000    0.00018613 
5.7000    0.00016041 
5.8000    0.00013824 
5.9000    0.00011913 
6.0000    0.00010267 
6.1000    0.00008848 
6.2000    0.00007625 
6.3000    0.00006572 
6.4000    0.00005663 
6.5000    0.00004881 
6.6000    0.00004206 
6.7000    0.00003625 
6.8000    0.00003124 
6.9000    0.00002692 
7.0000    0.00002320 
7.1000    0.00002000 
7.2000    0.00001723 
7.3000    0.00001485 
7.4000    0.00001280 
7.5000    0.00001103 
7.6000    0.00000951 
7.7000    0.00000819 
7.8000    0.00000706 
7.9000    0.00000608 
8.0000    0.00000524 
8.1000    0.00000452 
8.2000    0.00000389 
8.3000    0.00000336 
8.4000    0.00000289 
8.5000    0.00000249 
8.6000    0.00000215 
8.7000    0.00000185 
8.8000    0.00000160 
8.9000    0.00000137 
9.0000    0.00000118 
9.1000    0.00000102 
9.2000    0.00000088 
9.3000    0.00000076 
9.4000    0.00000065 
9.5000    0.00000056 
9.6000    0.00000049 
9.7000    0.00000042 
9.8000    0.00000036 
9.9000    0.00000031 
10.0000    0.00000027 

plot(x,y)