# NumPy - ptp() function

The NumPy ptp() function returns range of values (maximum - minimum) of an array or range of values along the specified axis.

The name of the function comes from the acronym for peak to peak.

### Syntax

```numpy.ptp(a, axis=None, out=None, keepdims=<no value>)
```

### Parameters

 `a` `Required. `Specify the input array. `axis` `Optional. `Specify axis or axes along which to operate. The default, axis=None, operation is performed on flattened array. `out` `Optional. `Specify the output array in which to place the result. It must have the same shape as the expected output. `keepdims` `Optional. `If this is set to True, the reduced axes are left in the result as dimensions with size one. With this option, the result will broadcast correctly against the input array.

### Return Value

Returns range of values of a. If axis is None, the result is a scalar value. If axis is given, the result is an array of dimension a.ndim - 1.

### Example: ptp() of flattened array

In the example below, ptp() function is used to return the range of values present in the array.

```import numpy as np
Arr = np.array([[10,20],[30, 40]])

print("Array is:")
print(Arr)

#range of values
print("\nRange of values:", np.ptp(Arr))
```

The output of the above code will be:

```Array is:
[[10 20]
[30 40]]

Range of values: 30
```

### Example: ptp() with axis parameter

When axis parameter is provided, range of values is calculated over the specified axes as shown in the example below.

```import numpy as np
Arr = np.array([[10,20,30],[70,80,90]])

print("Array is:")
print(Arr)

#Range of values along axis=0
print("\nRange of values along axis=0")
print(np.ptp(Arr, axis=0))

#Range of values along axis=1
print("\nRange of values along axis=1")
print(np.ptp(Arr, axis=1))
```

The output of the above code will be:

```Array is:
[[10 20 30]
[70 80 90]]

Range of values along axis=0
[60 60 60]

Range of values along axis=1
[20 20]
```

❮ NumPy - Functions

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