`scipy.optimize._optimize:rosen`

source: /scipy/optimize/_optimize.py :341

Signature

def rosen ( x )

Summary

The Rosenbrock function.

Extended Summary

The function computed is

sum(100.0*(x[1:] - x[:-1]**2.0)**2.0 + (1 - x[:-1])**2.0)

Parameters

x : array_like: 1-D array of points at which the Rosenbrock function is to be computed.

Returns

f : float: The value of the Rosenbrock function.

Notes

Array API Standard Support

rosen has experimental support for Python Array API Standard compatible backends in addition to NumPy. Please consider testing these features by setting an environment variable SCIPY_ARRAY_API=1 and providing CuPy, PyTorch, JAX, or Dask arrays as array arguments. The following combinations of backend and device (or other capability) are supported.

====================  ====================  ====================
Library               CPU                   GPU
====================  ====================  ====================
NumPy                 ✅                     n/a                 
CuPy                  n/a                   ✅                   
PyTorch               ✅                     ✅                   
JAX                   ✅                     ✅                   
Dask                  ✅                     n/a                 
====================  ====================  ====================

See dev-arrayapi for more information.

Examples

import numpy as np
from scipy.optimize import rosen
X = 0.1 * np.arange(10)

✓

rosen(X)

✗

For higher-dimensional input ``rosen`` broadcasts. In the following example, we use this to plot a 2D landscape. Note that ``rosen_hess`` does not broadcast in this manner.

import matplotlib.pyplot as plt
from mpl_toolkits.mplot3d import Axes3D
x = np.linspace(-1, 1, 50)
X, Y = np.meshgrid(x, x)
ax = plt.subplot(111, projection='3d')

✓

ax.plot_surface(X, Y, rosen([X, Y]))

✗

plt.show()

✓

`scipy.optimize._optimize:rosen`

Signature

Summary

Extended Summary

Parameters

Returns

Notes

Examples

See also

Aliases

Referenced by

This package