src/Interpolation/LambdaInterpolation.php
public function interpolate($x, $y, array $elevationOnBoundingBox)
    {
        $this->checkArguments($x, $y, $elevationOnBoundingBox);

        return $this->Lambda->__invoke($x, $y, $elevationOnBoundingBox);
    }
public function interpolate($x, $y, array $elevationOnBoundingBox)
    {
        $this->checkArguments($x, $y, $elevationOnBoundingBox);

        return $this->Lambda->__invoke($x, $y, $elevationOnBoundingBox);
    }
Interpolate.

p0------------p1
|      |
|      y
|      |
|--x-- Z
|
p2------------p3

@param  float                    $x                      x position of Z within bounding box, required: $x in [0.0, 1.0]
@param  float                    $y                      y position of Z within bounding box, required: $y in [0.0, 1.0]
@param  array                    $elevationOnBoundingBox elevation data on [p0, p1, p2, p3]
@return int                      estimated elevation on point Z
@throws InvalidArgumentException