The arccos()
method computes the arccosine (inverse cosine) of each element in an array.
Example
import numpy as np
# create an array of values between -1 and 1
values = np.array([-1, -0.5, 0, 0.5, 1])
# calculate the inverse cosine of each value
inverseCosines = np.arccos(values)
print(inverseCosines)
# Output: [3.14159265 2.0943951 1.57079633 1.04719755 0. ]
arccos() Syntax
The syntax of arccos()
is:
numpy.arccos(x, out = None, where = True, dtype = None)
arccos() Arguments
The arccos()
method takes following arguments:
x
- an input arrayout
(optional) - the output array where the result will be storedwhere
(optional) - a boolean array or condition indicating where to compute the arccosinedtype
(optional) - data type of the output array
arccos() Return Value
The arccos()
method returns an array with the corresponding inverse cosine values.
Example 1: Use of out and where in arccos()
import numpy as np
# create an array of values between -0.5 and 0.5
values = np.array([-0.5, -0.2, 0, 0.2, 0.5])
# create an array of zeros with the same shape as values
result = np.zeros_like(values, dtype = float)
# calculate inverse cosine where values >= 0 and store in result.
np.arccos(values, out = result, where = (values >= 0))
print(result)
Output
[0. 0. 1.57079633 1.36943841 1.04719755]
Here,
out = result
specifies that the output of thenp.arccos()
function should be stored in the result arraywhere=(values >= 0)
specifies that the inverse cosine operation should only be applied to elements in values that are greater than or equal to 0.
Example 2: Use of dtype Argument in arccos()
import numpy as np
# create an array of values
values = np.array([0, 1, -1])
# calculate the inverse cosine of each value with float data type
arccos Float = np.arccos(values, dtype = float)
print("Inverse Cosine with 'float' dtype:")
print(arccos Float)
# calculate the inverse cosine of each value with complex data type
arccosComplex = np.arccos(values, dtype = complex)
print("\nInverse Cosine with 'complex' dtype:")
print(arccosComplex)
Output
Inverse Cosine with 'float' dtype: [1.57079633 0. 3.14159265] Inverse Cosine with 'complex' dtype: [1.57079633-0.j 0. -0.j 3.14159265-0.j]
Here, by specifying the desired dtype
, we can control the data type of the output array according to our specific requirements.
Note: To learn more about the dtype
argument, please visit NumPy Data Types.