code: def interpolate_nearest(self, xi, yi, zdata):
          
          if zdata.size != self.npoints:
              raise ValueError('zdata should be same size as mesh')
  
          zdata = self._shuffle_field(zdata)
  
          ist = np.ones_like(xi, dtype=np.int32)
          ist, dist = _tripack.nearnds(xi, yi, ist, self._x, self._y,
                                       self.lst, self.lptr, self.lend)
          return zdata[ist - 1]
docs: Nearest-neighbour interpolation.
          Calls nearnd to find the index of the closest neighbours to xi,yi
  
          Parameters
          ----------
           xi : float / array of floats, shape (l,)
              x coordinates on the Cartesian plane
           yi : float / array of floats, shape (l,)
              y coordinates on the Cartesian plane
  
          Returns
          -------
           zi : float / array of floats, shape (l,)
              nearest-neighbour interpolated value(s) of (xi,yi)