# Python | Numpy np.chebvander() method

Last Updated : 11 Nov, 2019

With the help of `np.chebvander()` method, we can get the Pseudo-Vandermonde matrix from given array having degree which is passed as parameter by using `np.chebvander()` method.

Syntax : `np.chebvander(array, degree)`
Return : Return the matrix having size i.e array.size + (degree + 1).

Example #1 :
In this example we can see that by using `np.chebvander()` method, we are able to get the pseudo-vandermonde matrix using this method.

 `# import numpy ` `import` `numpy as np ` `import` `numpy.polynomial.chebyshev as cheb ` ` `  `# using np.chebvander() method ` `gfg ``=` `cheb.chebvander((``2``, ``4``, ``8``, ``1``), ``2``) ` ` `  `print``(gfg) `

Output :

[[ 1. 2. 7.]
[ 1. 4. 31.]
[ 1. 8. 127.]
[ 1. 1. 1.]]

Example #2 :

 `# import numpy ` `import` `numpy as np ` `import` `numpy.polynomial.chebyshev as cheb ` ` `  `# using np.chebvander() method ` `gfg ``=` `cheb.chebvander((``3``, ``5``, ``1``, ``10``), ``4``) ` ` `  `print``(gfg) `

Output :

[[1.0000e+00 3.0000e+00 1.7000e+01 9.9000e+01 5.7700e+02]
[1.0000e+00 5.0000e+00 4.9000e+01 4.8500e+02 4.8010e+03]
[1.0000e+00 1.0000e+00 1.0000e+00 1.0000e+00 1.0000e+00]
[1.0000e+00 1.0000e+01 1.9900e+02 3.9700e+03 7.9201e+04]]