def rigidmaty(s,params):
"""Return the 4x4 transfer matrix for motion of a rigid mass about
its y-axis."""
L = get_first_key_that_exists(params, ['Ly','L'])
r = get_first_key_that_exists(params, ['ry','r'])
Imat = get_first_key_that_exists(params, ['Iy','I'])
m=params['m']
if shape(Imat):
if max(shape(Imat))>=1:
Iy=Imat[1]
else:
Iy=Imat[0]
else:
Iy=Imat
#this matrix assumes +w_z is the state [w_z; theta_y; M_y; V_z] and is derived in
#Rmatrix_3D.m in E:\GT\Research\SAmii\modeling\transfer_matrix\threeD_TMM_derivations
# [ 1, -L, 0, 0]
# [ 0, 1, 0, 0]
# [ m*s^2*(L-r), s^2*Iz-m*s^2*r*(L-r), 1, L]
# [ m*s^2, -m*s^2*r, 0, 1]
matout=array([[1.,-L,0,0],[0,1.,0,0],[m*s**2*(L-r),s**2*Iy-m*s**2*r*(L-r),1.,L],[m*s**2,-m*s**2*r,0,1.]])
return matout
def rigidmatz(s,params):
"""Return the 4x4 transfer matrix for motion of a rigid mass about
its z-axis."""
L = get_first_key_that_exists(params, ['Lz','L'])
r = get_first_key_that_exists(params, ['rz','r'])
Imat = get_first_key_that_exists(params, ['Iz','I'])
m=params['m']
if shape(Imat):
Iz=Imat[2]
else:
Iz=Imat
#this matrix assumes +w_y is the state [w_y; theta_z; M_z; V_y] and is derived in
#Rmatrix_3D.m in E:\GT\Research\SAmii\modeling\transfer_matrix\threeD_TMM_derivations
# [ 1, L, 0, 0]
# [ 0, 1, 0, 0]
# [ -m*s^2*(L-r), s^2*Iz-m*s^2*r*(L-r), 1, -L]
# [ m*s^2, m*s^2*r, 0, 1]
matout=array([[1.,L,0,0],\
[0,1.,0,0],\
[-m*s**2*(L-r),s**2*Iz-m*s**2*r*(L-r),1.,-L],\
[m*s**2,m*s**2*r,0,1.]])
return matout