Regular Grid Multivariate linear interpolation

Non-recursive implementation of linear interpolation on regular grids.

Usage

• Code from this project has been integrated into scipy v0.14.0. See scipy.interpolate.RegularGridInterpolator.

• Cartesian grid regulargrid.cartesiangrid.CartesianGrid (equal spacing between points)

  Uses very fast implementation based on scipy.ndimage.map_coordinates

  Example:

  # create a 3-dimensional cartesian grid:
  limits = [(0, 1), (0, 1), (0, 1)]
  x = numpy.linspace(0, 1, 8)
  y = numpy.linspace(0, 1, 9)
  z = numpy.linspace(0, 1, 10)
  
  Z, Y = numpy.meshgrid(z, y)
  X = numpy.array([[x]]).transpose()
  
  # our grid values
  values = X**2 + Y - Z
  
  from regulargrid.cartesiangrid import CartesianGrid
  # does linear interpolation
  grid = CartesianGrid(limits, values)
  
  # interpolate for one point
  print grid([0.1], [0.5], [0.3])
  # interpolate many
  print grid([0.1, 0.3], [0.5, 0.5], [0.3, 0.2])
  

• Regular grid regulargrid.regulargrid.RegularGrid (unequal spacing between points)

Get

via pip/easy_install from PyPI:

pip install regulargrid

Source hosted at Github

References:

• Trilinear interpolation. (2013, January 17). In Wikipedia, The Free Encyclopedia. Retrieved 01:28, February 27, 2013, from http://en.wikipedia.org/w/index.php?title=Trilinear_interpolation&oldid=533448871
• Weiser, Alan, and Sergio E. Zarantonello. "A note on piecewise linear and multilinear table interpolation in many dimensions." MATH. COMPUT. 50.181 (1988): 189-196. http://www.ams.org/journals/mcom/1988-50-181/S0025-5718-1988-0917826-0/S0025-5718-1988-0917826-0.pdf