The isinf() function of NumPy

Overview:

The numpy.isinf() function checks each element of a NumPy array-like for infinity and returns the results as an ndarray containing Boolean values. When the input is a scalar it returns a single Boolean value.
The numpy.isinf() function returns True for both positive infinity and negative infinity. For "Not a number(nan)" the function isinf() will return False.

Example:

# Example Python program that checks the
# elements of an array-like for infinity
# excluding Not a Number
import numpy

array_nd = numpy.ndarray(shape = (2, 2))

array_nd[0][0] = numpy.nan
array_nd[0][1] = -numpy.inf # Negative infinity
array_nd[1][0] = numpy.inf + 1
array_nd[1][1] = 22/7

print("Contents of the ndarray:")
print(array_nd)

print("Is an element infinity:")
results = numpy.isinf(array_nd)
print(results)

Output:

Contents of the ndarray:

[[ nan -inf]

[ inf 3.14285714]]

Is an element infinity:

[[False True]

[ True False]]

Example 2:

# Example Python program that checks the
# different scalars for infiniti
import numpy

# Check a complex number for infiniti
aComplexNumber = complex(1, 2)
infResult = numpy.isinf(aComplexNumber)
print(infResult)

# Check a float for infiniti
aRealNumber = 1.99999999999999999999999999999999999999999999999999999999
print(type(aRealNumber))
infResult = numpy.isinf(aRealNumber)
print(infResult)

# Check googol for infiniti
googol = pow(10, 100)
print("Googol:")
print(googol)
infResult = numpy.isinf(googol)
print(infResult)

Output:

False

False

Googol:

10000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000

Traceback (most recent call last):

File "/Users/vinodh/PythonProgs/np_isinf_ex1.py", line 20, in <module>

infResult = numpy.isinf(googol)

^^^^^^^^^^^^^^^^^^^

TypeError: ufunc 'isinf' not supported for the input types, and the inputs could not be safely coerced to any supported types according to the casting rule ''safe''