ndarray-linear-interpolate

Multilinear (ie bilinear/trilinear) interpolation for ndarrays.

Example

var ndarray = require("ndarray")
var interp = require("ndarray-linear-interpolate")

var x = ndarray(new Float32Array(9), [3, 3])
x.set(1, 1, 1.0)

for(var u=0.0, u<=3.0; u+=0.25) {
  var row = []
  for(var v=0.0; v<=3.0; v+=0.25) {
    row.push(interp(x, u, v))
  }
  console.log(row.join(" "))
}

//Prints out:
//
//    0 0 0 0 0 0 0 0 0 0 0 0 0
//    0 0.0625 0.125 0.1875 0.25 0.1875 0.125 0.0625 0 0 0 0 0
//    0 0.125 0.25 0.375 0.5 0.375 0.25 0.125 0 0 0 0 0
//    0 0.1875 0.375 0.5625 0.75 0.5625 0.375 0.1875 0 0 0 0 0
//    0 0.25 0.5 0.75 1 0.75 0.5 0.25 0 0 0 0 0
//    0 0.1875 0.375 0.5625 0.75 0.5625 0.375 0.1875 0 0 0 0 0
//    0 0.125 0.25 0.375 0.5 0.375 0.25 0.125 0 0 0 0 0
//    0 0.0625 0.125 0.1875 0.25 0.1875 0.125 0.0625 0 0 0 0 0
//    0 0 0 0 0 0 0 0 0 0 0 0 0
//    0 0 0 0 0 0 0 0 0 0 0 0 0
//    0 0 0 0 0 0 0 0 0 0 0 0 0
//    0 0 0 0 0 0 0 0 0 0 0 0 0
//    0 0 0 0 0 0 0 0 0 0 0 0 0
//

Install

npm install ndarray-linear-interpolate

require("ndarray-linear-interpolate")(array, x, y, z, ...)

Interpolates values on an ndarray.

• array the array to interpolate from
• x, y, z... the coordinate to evaluate the interpolated grid at

Returns The multilinearly interpolated value

Note To avoid the overhead of variable arguments, special interfaces are available for 1, 2 and 3 dimensions. You can access these using:

• require("ndarray-linear-interpolate").d1
• require("ndarray-linear-interpolate").d2
• require("ndarray-linear-interpolate").d3

Credits

(c) 2013 Mikola Lysenko. MIT License