#! /usr/bin/env python

import openturns as ot

ot.TESTPREAMBLE()

inputDimension = 3
outputDimension = 2
# Center
center = ot.Point(inputDimension)
center[0] = -1
center[1] = 0.5
center[2] = 1
# Constant term
constant = ot.Matrix(inputDimension, outputDimension)
constant[0, 0] = 1.0
constant[1, 0] = 2.0
constant[2, 0] = 5.0
constant[0, 1] = 7.0
constant[1, 1] = 9.0
constant[2, 1] = 3.0
# Linear term
linear = ot.SymmetricTensor(inputDimension, outputDimension)
linear[0, 0, 0] = 7.0
linear[0, 0, 1] = -7.0
linear[0, 1, 0] = 8.0
linear[0, 1, 1] = -8.0
linear[0, 2, 0] = 9.0
linear[0, 2, 1] = -9.0
linear[1, 0, 0] = 8.0
linear[1, 0, 1] = -8.0
linear[1, 1, 0] = 10.0
linear[1, 1, 1] = -10.0
linear[1, 2, 0] = 11.0
linear[1, 2, 1] = -11.0
linear[2, 0, 0] = 9.0
linear[2, 0, 1] = -9.0
linear[2, 1, 0] = 11.0
linear[2, 1, 1] = -11.0
linear[2, 2, 0] = 12.0
linear[2, 2, 1] = -12.0

# myFunction = linear * (X- center) + constant
myGradient = ot.LinearGradient(center, constant, linear)
myGradient.setName("linearGradient")
inPoint = ot.Point(inputDimension)
inPoint[0] = 7.0
inPoint[1] = 8.0
inPoint[2] = 9.0
outMatrix = myGradient.gradient(inPoint)
print("myGradient=", repr(myGradient))
print(myGradient.getName(), "( ", repr(inPoint), " ) = ", repr(outMatrix))