From ND to 1D arrays

by

Use np.ravel (for a 1D view) or np.ndarray.flatten (for a 1D copy) or np.ndarray.flat (for an 1D iterator):

In [12]: a = np.array([[1,2,3], [4,5,6]])

In [13]: b = a.ravel()

In [14]: b
Out[14]: array([1, 2, 3, 4, 5, 6])

Note that ravel() returns a view of a when possible. So modifying b also modifies a. ravel() returns a view when the 1D elements are contiguous in memory, but would return a copy if, for example, a were made from slicing another array using a non-unit step size (e.g. a = x[::2]).

If you want a copy rather than a view, use

In [15]: c = a.flatten()

If you just want an iterator, use np.ndarray.flat:

In [20]: d = a.flat

In [21]: d
Out[21]: <numpy.flatiter object at 0x8ec2068>

In [22]: list(d)
Out[22]: [1, 2, 3, 4, 5, 6]

More Related Contents:

  1. value error in python script
  2. Pandas conditional creation of a series/dataframe column
  3. How do I get indices of N maximum values in a NumPy array?
  4. How to convert a PIL Image into a numpy array?
  5. How to apply a disc shaped mask to a NumPy array?
  6. using an numpy array as indices of the 2nd dim of another array? [duplicate]
  7. How to evaluate the sum of values within array blocks
  8. Multiple linear regression in Python
  9. Numpy – create matrix with rows of vector
  10. Numpy integer nan [duplicate]
  11. Take multiple lists into dataframe
  12. Using Numpy Vectorize on Functions that Return Vectors
  13. Convert numpy.datetime64 to string object in python
  14. Matplotlib: how to make imshow read x,y coordinates from other numpy arrays?
  15. Numpy individual element access slower than for lists
  16. Why using an array as an index changes the shape of a multidimensional ndarray?
  17. How to get stable results with TensorFlow, setting random seed
  18. How to multiply individual elements of a list with a number?
  19. Numpy isnan() fails on an array of floats (from pandas dataframe apply)
  20. Installing lapack for numpy
  21. Adding colors to a 3d quiver plot in matplotlib
  22. How to resample a dataframe with different functions applied to each column?
  23. Converting 2D Numpy array of grayscale values to a PIL image
  24. Convert a column of timestamps into periods in pandas
  25. Consecutive, Overlapping Subsets of Array (NumPy, Python)
  26. Can’t import cv2; “DLL load failed”
  27. A numpy array unexpectedly changes when changing another one despite being separate
  28. Computing cross-correlation function?
  29. Generate random array of floats between a range
  30. Understanding scipy deconvolve

Leave a Comment