We use the polynomial.polyval2d() which is a numpy’s function in Python to assess a 2-D polynomial at the positions (x, y). The technique returns the values of the given two-dimensional polynomial at places produced by x and y pairs. x and y are parameters. At the points (x, y), the two-dimensional series is assessed, where x and y must have the same form. If x or y is a list or tuple, it is first transformed to an ndarray, otherwise, it is kept unmodified and is regarded as a scalar if it isn’t a ndarray.
The parameter ‘Arr’ is an Array of coefficients sorted so that Arr[i,j] contains the coefficient of the term of multidegree i,j. The remaining indices enumerate numerous sets of coefficients if ‘Arr’ has a dimension higher than two. If the form of ‘Arr’ has less than two dimensions, ones are implicitly added to make it two-dimensional. Arr .shape[2:] + x.shape is the shape of the result.
Below are the steps to evaluate 2-D polynomial at point (x,y) :
Step 1: Import NumPy and polyval2d libraries as shown below :
Python3
import numpy as np from numpy.polynomial.polynomial import polyval2d |
Step 2: Now we have to create a multidimensional array ‘Arr’ of coefficients as shown below :
Python3
Arr = np.arange( 4 ).reshape( 2 , 2 ) |
Step 3: Define x and y (the points at which we are evaluating 2-D polynomial) as shown below :
Python3
x = [ 1 , 2 ] y = [ 2 , 3 ] |
Step 3: Use the polynomial.polyval2d() function to assess a 2-D polynomial at locations (x, y) as shown below :
Python3
print ( "Result : \n" ,polyval2d(x,y, Arr)) |
Example 1 :
Python3
# importing numpy and polyval2d import numpy as np from numpy.polynomial.polynomial import polyval2d # Create a multidimensional array of # coefficients or a matrix Arr = np.matrix([[ 4 , 2 ], [ 6 , 3 ]]) # Defining x and y x = [ 2 , 3 ] y = [ 1 , 2 ] # in order to evaluate a 2-D polynomial # at points (x, y), we are using the # polynomial.polyval2d() method in Python # Numpy print (polyval2d(x, y, Arr)) |
Output :
[24. 44.]
Example 2 :
Python3
# import polyval2d from numpy from numpy.polynomial.polynomial import polyval2d # create a 2 dimensional array # of coefficient or a matrix Arr = [[ 4 , 2 ], [ 6 , 3 ]] # evaluate the 2D polynomial at # point (x,y) using polyval2d # function and print the result print (polyval2d([ 2 , 3 ],[ 1 , 2 ],Arr)) |
Output :
[24. 44.]