MATLAB: I’m trying to plot these points, please help

plotting

x(10-110) increments of 1

y=(W*L)*(sqrt((h^2)+(x^2)))/(h*x) (for every x value between 10-110)

W=500

L=120

h=50

Everytime I tried plotting x and y not all the y values from the formula would show on the graph, along with there being no line to show the change of Y/X.

Best Answer

x=10:1:110;
W=500;
L=120;
h=50;
y=(W*L)*(sqrt((h^2)+(x.^2)))./(h.*x) ;
figure
plot(x,y)

things to note:

define the variables BEFORE evaluating them in an equation.

dot operator for element wise multiplication / division

https://www.mathworks.com/help/matlab/learn_matlab/matrices-and-arrays.html

Related Solutions

MATLAB: How to substitute an array of double values into a symbolic equation

structfun(@(F) double(subs(F, {Var_matrix}, {G_matrix})), Sol, 'uniform', 0)

MATLAB: Runge Kutta method for coupled oscillator system.

Do you mean like this

%initializing x,y,t
h=0.1;   %step size
t=0:h:50;
x1 = zeros(1,numel(t)); y1 = x1; x2 = x1; y2 = x1;
x1(1)=1;
y1(1)=1;
x2(1)=2;
y2(1)=2;
%value of constants
a=0.1;
b=0.3;
omega=4;
Cnp=0.2;
G=1;
%ode
p=@(x1,y1,x2,y2) (a-x1^2-y1^2)*x1-omega*y1+G*Cnp*(x2-x1);
q=@(x1,y1,x2,y2) (a-x1^2-y1^2)*y1+omega*x1+G*Cnp*(y2-y1);
%loop
for i=1:(length(t)-1)
    k1=p(x1(i),y1(i),x2(i),y2(i));
    l1=q(x1(i),y1(i),x2(i),y2(i));
 
    
    k2=p((x1(i)+(h/2)*k1),(y1(i)+(h/2)*l1),(x2(i)+(h/2)*k1),(y2(i)+(h/2)*l1));
    l2=q((x1(i)+(h/2)*k1),(y1(i)+(h/2)*l1),(x2(i)+(h/2)*k1),(y2(i)+(h/2)*l1));
      
    k3=p((x1(i)+(h/2)*k2),(y1(i)+(h/2)*l2),(x2(i)+(h/2)*k2),(y2(i)+(h/2)*l2));
    l3=q((x1(i)+(h/2)*k2),(y1(i)+(h/2)*l2),(x2(i)+(h/2)*k2),(y2(i)+(h/2)*l2));
      
    k4=p((x1(i)+k3*h),(y1(i)+l3*h),(x2(i)+k3*h),(y2(i)+l3*h));
    l4=q((x1(i)+k3*h),(y1(i)+l3*h),(x2(i)+k3*h),(y2(i)+l3*h));
    
      x1(i+1) = x1(i) + h*(k1+2*k2+2*k3+k4)/6;
      y1(i+1) = y1(i) + h*(l1+2*l2+2*l3+l4)/6;
      x2(i+1) = x2(i) + h*(k1+2*k2+2*k3+k4)/6;
      y2(i+1) = y2(i) + h*(l1+2*l2+2*l3+l4)/6;
end
%draw
plot(t,x1,'r',t,x2,'y')
xlabel('t','fontsize',14,'fontweight','bold')
ylabel('x1 & x2','fontsize',14,'fontweight','bold')
set(gca,'Color','k')
legend('x1','x2','TextColor','w')
figure
plot(t,y1,'r',t,y2,'y')
xlabel('t','fontsize',14,'fontweight','bold')
ylabel('y1 & y2','fontsize',14,'fontweight','bold')
set(gca,'Color','k')
legend('y1','y2','TextColor','w')

Best Answer

Related Solutions

MATLAB: How to substitute an array of double values into a symbolic equation

MATLAB: Runge Kutta method for coupled oscillator system.

Related Question