the program is plotted once, then showing error, is something error in program

format long

a = 0;

b = 4;

h = 0.1;

k = 0.033;

L = 0.5;

s = 0.1;

tc = 70E-9;

n = (b-a)/h ;

t = a + (0:n)*h;

y(1) = 0;

func1 = @(y) ((-(s^2)*k/tc)*sin(y - pi/2) + L*(s^2)/(2*tc)*sin(y + pi/2)/sqrt(1 + cos(y + pi/2)));

for i = 1:n

k1 = func1(y(i));

k2 = func1 (y(i)+(k1/2)*h);

k3 = func1 (y(i)+(k2/2)*h);

k4 = func1(y(i)+(k3*h));

y(i+1) = y(i) + (h/6)*(k1+(2*(k2+k3))+k4);

end

plot(t,y)

==================================

output:- Error using plot

Vectors must be the same length.

[KSSV]

It is working fine...clear you variables once and run the code.

a = 0;
b = 4;
h = 0.1;
k = 0.033;  
L  = 0.5; 
s = 0.1;  
tc  = 70E-9;  
n = (b-a)/h ;
t = a + (0:n)*h;
y(1) = 0;
func1 = @(y) ((-(s^2)*k/tc)*sin(y - pi/2) + L*(s^2)/(2*tc)*sin(y + pi/2)/sqrt(1 + cos(y + pi/2)));         
for i = 1:n
    k1 = func1(y(i));
    k2 = func1 (y(i)+(k1/2)*h);
    k3 = func1 (y(i)+(k2/2)*h);
    k4 = func1(y(i)+(k3*h));
    y(i+1) = y(i) + (h/6)*(k1+(2*(k2+k3))+k4);   
   
end
whos t y 

  Name      Size            Bytes  Class     Attributes

  t         1x41              328  double              
  y         1x41              328  double              

plot(t,y)

[SAHIL SAHOO]

why I'm geting y 1 * 101 and you got 1* 41

Answer 1

[KSSV]

You initialize the value of y before for loop.

y = zeros(1,n) ; 
y(1) = 0;
func1 = @(y) ((-(s^2)*k/tc)*sin(y - pi/2) + L*(s^2)/(2*tc)*sin(y + pi/2)/sqrt(1 + cos(y + pi/2)));