NASA Ocean Color

ocssw V2022
 def mtoq(rm):
     # Convert direction cosine matrix to equivalent quaternion
     # input: rm
     # output: q
     # Ported from mtoq.pro by Fred Patt
     # Liang Hong, 2/18/2020
     
     import numpy as np
     
     q = np.zeros(4)
     e = np.zeros(3)
  
     # Compute Euler angle
     cphi = (rm[0,0]+rm[1,1]+rm[2,2]-1.0)/2.0
     if (np.abs(cphi) < 0.98):
         phi = np.arccos(cphi)
     else:
         ssphi = ((rm[1,0]-rm[0,1])**2 + (rm[0,2]-rm[2,0])**2 + (rm[2,1]-rm[1,2])**2)/4.0
         phi = np.arcsin(np.sqrt(ssphi))
         if (cphi < 0):
             phi = np.pi - phi
     
     # Compute Euler axis
     e[0] = (rm[2,1]-rm[1,2])/(np.sin(phi)*2.0)
     e[1] = (rm[0,2]-rm[2,0])/(np.sin(phi)*2.0)
     e[2] = (rm[1,0]-rm[0,1])/(np.sin(phi)*2.0)
     e = e/np.sqrt(np.sum(e*e))
  
     # Compute quaternion
     q[0] = e[0]*np.sin(phi/2.0)
     q[1] = e[1]*np.sin(phi/2.0)
     q[2] = e[2]*np.sin(phi/2.0)
     q[3] = np.cos(phi/2.0)
     
     return q
mtoq.mtoq
def mtoq(rm)
Definition: mtoq.py:1