#! /usr/bin/env python

import openturns as ot

ot.TESTPREAMBLE()


matrix1 = ot.SymmetricMatrix(2)
matrix1.setName("matrix1")
matrix1[0, 0] = 1.0
matrix1[1, 0] = 5.0
matrix1[1, 1] = 12.0
print("matrix1=", matrix1)
print("matrix1=")
print(matrix1.__str__())

pt = ot.Point(0)
pt.add(5.0)
pt.add(0.0)
print("pt=", pt)

result = matrix1.solveLinearSystem(pt)
print("result=", result)
#    print "verif. ", matrix1 * result - pt

determinant = matrix1.computeDeterminant()
print("determinant= %.1f" % determinant)

b = ot.Matrix(2, 3)
b[0, 0] = 5.0
b[1, 0] = 0.0
b[0, 1] = 10.0
b[1, 1] = 1.0
b[0, 2] = 15.0
b[1, 2] = 2.0
result2 = ot.Matrix()
result2 = matrix1.solveLinearSystem(b)
print("result2=", result2)
print("result2=")
print(result2.__str__())

ev = matrix1.computeEigenValues()
print("ev=", ev)

ev, evect = matrix1.computeEV()
print("ev=", ev)
print("evect=", repr(evect))
print("evect=")
print(evect.__str__())
maxModule = matrix1.computeLargestEigenValueModule(10, 1e-2)
print("max |ev|=%.6g" % maxModule)

# Check the high dimension determinant computation
matrix3 = ot.SymmetricMatrix(3)
matrix3[0, 0] = 1.0
matrix3[0, 1] = 2.0
matrix3[0, 2] = 3.0
matrix3[1, 1] = 2.5
matrix3[1, 2] = -3.5
matrix3[2, 2] = 2.5

print("matrix3=")
print(matrix3.__str__())
# sign = 0.0
# value = matrix3.computeLogAbsoluteDeterminant(sign)
# print "log(|det|)=", value, ", sign=", sign
value = matrix3.computeDeterminant()
print("det=", value)