def DIFEQ(self,Qd,Q,t,P): #/ -------------------------------------------------------------------------- if (0==self.done): G = P[jG] self.x[0] = Q[iX1] self.y[0] = Q[iY1] self.x[1] = Q[iX2] self.y[1] = Q[iY2] self.x[2] = Q[iX3] self.y[2] = Q[iY3] self.x[3] = Q[iX4] self.y[3] = Q[iY4] self.m[0] = P[jM1] self.m[1] = P[jM2] self.m[2] = P[jM3] self.m[3] = P[jM4] for k in range(1,NN): for i in range(0,k): self.dx[k][i] = self.x[k] - self.x[i] self.dy[k][i] = self.y[k] - self.y[i] self.dx[i][k] = -self.dx[k][i] self.dy[i][k] = -self.dy[k][i] for k in range(1,NN): for i in range(0,k): tt = (self.dx[k][i]*self.dx[k][i]) + (self.dy[k][i]*self.dy[k][i]) self.DEN[k][i] = Math.POWER(tt,-1.5) self.DEN[i][k] = self.DEN[k][i] for i in range(0,NN): sumx = 0.0 sumy = 0.0 for k in range(0,NN): if k != i: tk = self.m[k]*self.DEN[k][i] sumx += (tk*self.dx[k][i]) sumy += (tk*self.dy[k][i]) self.xdd[i] = G*sumx self.ydd[i] = G*sumy Qd[iVX1] = self.xdd[0] Qd[iVY1] = self.ydd[0] Qd[iX1] = Q[iVX1] Qd[iY1] = Q[iVY1] Qd[iVX2] = self.xdd[1] Qd[iVY2] = self.ydd[1] Qd[iX2] = Q[iVX2] Qd[iY2] = Q[iVY2] Qd[iVX3] = self.xdd[2] Qd[iVY3] = self.ydd[2] Qd[iX3] = Q[iVX3] Qd[iY3] = Q[iVY3] Qd[iVX4] = self.xdd[3] Qd[iVY4] = self.ydd[3] Qd[iX4] = Q[iVX4] Qd[iY4] = Q[iVY4]
def DIFEQ(self, Qd, Q, t, P):
#/ --------------------------------------------------------------------------
if 0 == self.done:
xd1 = Q[0]
x1 = Q[4]
yd1 = Q[1]
y1 = Q[5]
xd2 = Q[2]
x2 = Q[6]
yd2 = Q[3]
y2 = Q[7]
m1 = P[0]
m2 = P[2]
dx21 = x2 - x1
dy21 = y2 - y1
dx12 = x1 - x2
dy12 = y1 - y2
r12sq = (dx12 * dx12) + (dy12 * dy12)
den = Math.POWER(r12sq, 1.5)
if den > 0.0:
pass
else:
print "INFINITY\n"
a1 = Math.N_G * m2 * dx21
a2 = Math.N_G * m2 * dy21
a3 = Math.N_G * m1 * dx12
a4 = Math.N_G * m1 * dy12
Qd[0] = Math.SAFEDIV(a1, den)
Qd[1] = Math.SAFEDIV(a2, den)
Qd[2] = Math.SAFEDIV(a3, den)
Qd[3] = Math.SAFEDIV(a4, den)
Qd[4] = xd1
Qd[5] = yd1
Qd[6] = xd2
Qd[7] = yd2
