# NumPy tanh()

The `tanh()` function calculates the hyperbolic tangent of each element in an array.

### Example

``````import numpy as np

# create an array of values
values = np.array([-2, -1, 0, 1, 2])

# calculate the hyperbolic tangent of each value
result = np.tanh(values)

print(result)

# Output:[-0.96402758 -0.76159416  0.          0.76159416  0.96402758]``````

## tanh() Syntax

The syntax of `tanh()` is:

``numpy.tanh(x, out = None, where = True, dtype = None)``

## tanh() Arguments

The `tanh()` method takes following arguments:

• `x` - an input array
• `out` (optional) - the output array where the result will be stored
• `where` (optional) - a boolean array or condition indicating where to compute the hyperbolic tangent
• `dtype` (optional) - data type of the output array

## tanh() Return Value

The `tanh()` method returns an array with the corresponding hyperbolic tangent values of its elements.

## Example 1: Use of out and where in tanh()

``````import numpy as np

values = np.array([-1, 0, 1, 2, 3])

# create an output array of the same shape and data type as 'values', filled with zeros
result = np.zeros_like(values, dtype=float)

# calculate the hyperbolic tangent where values>=0 and store in result
np.tanh(values, out=result, where=(values >= 0))

print(result)``````

Output

`[0.         0.         0.76159416 0.96402758 0.99505475]`

Here,

• `out=result` specifies that the output of the `np.tanh()` function should be stored in the result array
• `where=(values >= 0)` specifies that the hyperbolic operation should only be applied to elements in values that are greater than or equal to 0.

## Example 2: Use of dtype Argument in tanh()

``````import numpy as np

# create an array of values
values = np.array([-0.5, -0.2, 0, 0.2, 0.5])

# calculate the hyperbolic tangent of each value with a specific dtype
tanh_values_float = np.tanh(values, dtype=float)
tanh_values_complex = np.tanh(values, dtype=complex)

print("Hyperbolic tangents with 'float' dtype:")
print(tanh_values_float)

print("\nHyperbolic tangents with 'complex' dtype:")
print(tanh_values_complex)``````

Output

```Hyperbolic tangents with 'float' dtype:
[-0.46211716 -0.19737532  0.          0.19737532  0.46211716]

Hyperbolic tangents with 'complex' dtype:
[-0.46211716+0.j -0.19737532+0.j  0.        +0.j  0.19737532+0.j
0.46211716+0.j]```

Here, by specifying the desired `dtype`, we can specify the data type of the output array according to our requirements.

Note: To learn more about the `dtype` argument, please visit NumPy Data Types.