def copyto(self, src, where=None):
        """Emulates function `copyto` in NumPy.

       Parameters
       ----------

       where: (N,) bool ndarray
            True if particle n in src must be copied. 
       src: (N,) `ThetaParticles` object 
            source 

       for each n such that where[n] is True, copy particle n in src
       into self (at location n)
        """
        for k in self.containers:
            v = self.__dict__[k]
            if isinstance(v, np.ndarray):
                np.copyto(v, src.__dict__[k], where=where)
            else:
                v.copyto(src.__dict__[k], where=where)
def copyto ( self , src , where = None ) : for k in self . containers : v = self . __dict__ [ k ] if isinstance ( v , np . ndarray ) : np . copyto ( v , src . __dict__ [ k ] , where = where ) else : v . copyto ( src . __dict__ [ k ] , where = where )
Emulates function `copyto` in NumPy.

       Parameters
       ----------

       where: (N,) bool ndarray
            True if particle n in src must be copied. 
       src: (N,) `ThetaParticles` object 
            source 

       for each n such that where[n] is True, copy particle n in src
       into self (at location n)