Use numpy.full():
import numpy as np
np.full(
shape=10,
fill_value=3,
dtype=np.int
)
> array([3, 3, 3, 3, 3, 3, 3, 3, 3, 3])
Answer from Daniel Lenz on Stack Overflowpython: converting an numpy array data type from int64 to int - Stack Overflow
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Use numpy.full():
import numpy as np
np.full(
shape=10,
fill_value=3,
dtype=np.int
)
> array([3, 3, 3, 3, 3, 3, 3, 3, 3, 3])
Very easy 1)we use arange function :-
arr3=np.arange(0,10)
output=array([0, 1, 2, 3, 4, 5, 6, 7, 8, 9])
2)we use ones function whose provide 1 and after we will do multiply 3 :-
arr4=np.ones(10)*3
output=array([3., 3., 3., 3., 3., 3., 3., 3., 3., 3.])
Use the astype method.
>>> x = np.array([[1.0, 2.3], [1.3, 2.9]])
>>> x
array([[ 1. , 2.3],
[ 1.3, 2.9]])
>>> x.astype(int)
array([[1, 2],
[1, 2]])
Some numpy functions for how to control the rounding: rint, floor,trunc, ceil. depending how u wish to round the floats, up, down, or to the nearest int.
>>> x = np.array([[1.0,2.3],[1.3,2.9]])
>>> x
array([[ 1. , 2.3],
[ 1.3, 2.9]])
>>> y = np.trunc(x)
>>> y
array([[ 1., 2.],
[ 1., 2.]])
>>> z = np.ceil(x)
>>> z
array([[ 1., 3.],
[ 2., 3.]])
>>> t = np.floor(x)
>>> t
array([[ 1., 2.],
[ 1., 2.]])
>>> a = np.rint(x)
>>> a
array([[ 1., 2.],
[ 1., 3.]])
To make one of this in to int, or one of the other types in numpy, astype (as answered by BrenBern):
a.astype(int)
array([[1, 2],
[1, 3]])
>>> y.astype(int)
array([[1, 2],
[1, 2]])
Use .astype.
>>> a = numpy.array([1, 2, 3, 4], dtype=numpy.float64)
>>> a
array([ 1., 2., 3., 4.])
>>> a.astype(numpy.int64)
array([1, 2, 3, 4])
See the documentation for more options.
While astype is probably the "best" option there are several other ways to convert it to an integer array. I'm using this arr in the following examples:
>>> import numpy as np
>>> arr = np.array([1,2,3,4], dtype=float)
>>> arr
array([ 1., 2., 3., 4.])
The int* functions from NumPy
>>> np.int64(arr)
array([1, 2, 3, 4])
>>> np.int_(arr)
array([1, 2, 3, 4])
The NumPy *array functions themselves:
>>> np.array(arr, dtype=int)
array([1, 2, 3, 4])
>>> np.asarray(arr, dtype=int)
array([1, 2, 3, 4])
>>> np.asanyarray(arr, dtype=int)
array([1, 2, 3, 4])
The astype method (that was already mentioned but for completeness sake):
>>> arr.astype(int)
array([1, 2, 3, 4])
Note that passing int as dtype to astype or array will default to a default integer type that depends on your platform. For example on Windows it will be int32, on 64bit Linux with 64bit Python it's int64. If you need a specific integer type and want to avoid the platform "ambiguity" you should use the corresponding NumPy types like np.int32 or np.int64.
Make a sample array
In [206]: x=np.array([1e9, 2e10, 1e6])
In [207]: x
Out[207]: array([ 1.00000000e+09, 2.00000000e+10, 1.00000000e+06])
We can convert to ints - except notice that the largest one is too large the default int32
In [208]: x.astype(int)
Out[208]: array([ 1000000000, -2147483648, 1000000])
In [212]: x.astype(np.int64)
Out[212]: array([ 1000000000, 20000000000, 1000000], dtype=int64)
Writing a csv with the default format (float) (this is the default format regardless of the array dtype):
In [213]: np.savetxt('text.txt',x)
In [214]: cat text.txt
1.000000000000000000e+09
2.000000000000000000e+10
1.000000000000000000e+06
We can specify a format:
In [215]: np.savetxt('text.txt',x, fmt='%d')
In [216]: cat text.txt
1000000000
20000000000
1000000
Potentially there are 3 issues:
- integer v float in the array itself, it's
dtype - display or print of the array
- writing the array to a csv file
It is a printing option, see the documentation: printing options. Briefly stated: you need to use the suppress option when printing:
np.set_printoptions(suppress=True) # for small floating point.
np.set_printoptions(suppress=True, formatter={'all':lambda x: str(x)})