How to set the number of digits after the decimal place displayed in a numpy float?

Question

Per the docs I set the number of digits of precision for printing a numpy float to 8 and expected to see 1.12345679 from this code but did not:

import numpy as np

np.set_printoptions(precision=8)

x = np.float_(1.123456789)

print x

http://stackoverflow.com/questions/455612/limiting-floats-to-two-decimal-points — Christian Hain, Apr 11 '17 at 02:27
or perhaps: https://docs.scipy.org/doc/numpy/reference/generated/numpy.around.html — Christian Hain, Apr 11 '17 at 02:28
`set_printoptions` controls how the arrays are displayed that's why it is not working, if you print that as `print(np.array([np.float_(1.123456789)]))`. It will give you the right result. Your best bet seems to be string formatting during print. — umutto, Apr 11 '17 at 02:30
rounding functions change the data but do not force the representation to be 8 places after the deceimal unconditionally. — Terrence Brannon, Apr 11 '17 at 03:13

score 3 · Answer 1 · answered Apr 11 '17 at 02:31

3

As the comments have suggested you could use numpy.around.

import numpy as np

np.set_printoptions(precision=4)

x = np.float_(1.123456789)
print x

x = np.around(x, 8)
print x

This outputs:

1.123456789
1.12345679

answered Apr 11 '17 at 02:31

axwr

1 Answers1