double pendulum

 

float theta1,vtheta1,theta2,vtheta2;

float x1,y1,x2,y2;

float vx,vy;

float g=9.8;

float l= 4;

void init() {

theta1 =0; vtheta1 = 0.0;

theta2 =0; vtheta2 = 0.0;

//l= density*l;

}

void motion(float dt) {

float a= 2;

float b= cos(theta1-theta2);

float c= cos(theta1-theta2);

float d = 1;

float b1= vtheta1*vtheta2*sin(theta1-theta2)-2*g/l*sin(theta1)+ax*vx;

float b2 = -vtheta1*vtheta2*sin(theta1-theta2)-g/l*sin(theta2)+ay*vy;

float det = a*d-b*c;

float r1= (d*b1-b*b2)/det;

float r2= (-c*b1+a*b2)/det;

vtheta1+= dt*r1;

vtheta2+= dt*r2;

// vtheta1+= dt/l*(ax*cos(theta1)+sin(theta1)*(-g+ay));

// vphi+=dt/(l*sin(phi))*(ax*sin(phi)-ay*cos(phi));

theta1+= vtheta1*dt;

vtheta1*=0.98;

// vtheta2+= vtheta1+dt/l*(ax*cos(theta2)+sin(theta2)*(-g+ay));

theta2+= vtheta2*dt;

vtheta2*=0.98;

vx+=dt*ax;

vy+=dt*ay;

}

void pendulum() {

strokeWeight(10);

k=100;

float theta1,vtheta1,theta2,vtheta2;

float x1,y1,x2,y2;

float vx,vy;

float g=9.8;

float l= 4;

void init() {

theta1 =0; vtheta1 = 0.0;

theta2 =0; vtheta2 = 0.0;

//l= density*l;

}

void motion(float dt) {

float a= 2;

float b= cos(theta1-theta2);

float c= cos(theta1-theta2);

float d = 1;

float b1= vtheta1*vtheta2*sin(theta1-theta2)-2*g/l*sin(theta1)+ax*vx;

float b2 = -vtheta1*vtheta2*sin(theta1-theta2)-g/l*sin(theta2)+ay*vy;

float det = a*d-b*c;

float r1= (d*b1-b*b2)/det;

float r2= (-c*b1+a*b2)/det;

vtheta1+= dt*r1;

vtheta2+= dt*r2;

// vtheta1+= dt/l*(ax*cos(theta1)+sin(theta1)*(-g+ay));

// vphi+=dt/(l*sin(phi))*(ax*sin(phi)-ay*cos(phi));

theta1+= vtheta1*dt;

vtheta1*=0.98;

// vtheta2+= vtheta1+dt/l*(ax*cos(theta2)+sin(theta2)*(-g+ay));

theta2+= vtheta2*dt;

vtheta2*=0.98;

vx+=dt*ax;

vy+=dt*ay;

}

void pendulum() {

strokeWeight(10);

k=100;

x1=k*l*sin(theta1)+x0;

y1=k*l*cos(theta1)+y0;

x2=x1+k*l*sin(theta2);

y2=y1+k*l*cos(theta2);

stroke(255);

float k=1000;

stroke(255);

line(x0,y0,x1,y1);

line(x1,y1,x2,y2);

stroke(255,0,0);fill(255,255,0);

// ellipse(x1,y1,60,60);

fill(200,0,0);noStroke();

lights();

//ambientLight(0,0,0,0,-1,0);

lightSpecular(255,255,255);

directionalLight(200,100,100,-1,0,-1);

specular(200);

pushMatrix();

translate(x1,y1);

sphere(50);

popMatrix();

pushMatrix();

translate(x2,y2);

sphere(60);

popMatrix();

noFill();stroke(200);

ellipse(x0,y0,60,60);

ellipse(x0,y0,10,10);

}