1. Overview
In Numpy, range() is mainly used to generate arrays, and the specific usage is as follows;
2. arange()
2.1 Syntax
(start, stop, step, dtype = None)
Returns the value of uniformly spaced within a given interval.
The value is generated within the half-open interval [start, stop] (in other words, the interval that starts but does not include the stop),The return is ndarray.
2.2 Parameters
-
start——Start position, number,Optional, the default starting value is 0 -
stop——Stop position, number -
step—— Step size, number,Optional, the default step size is 1, if step is specified, start must also be given. -
dtype——The type of output array. If dtype is not given, the data type is inferred from other input parameters.
return:
arange：ndarray
An array of evenly spaced values.
Notice:
- For floating point parameters (the parameter is floating point), the length of the result is ceil((stop - start)/step)) Due to floating point overflow, this rule may cause the last element to be larger than stop.
- Therefore, pay special attention to it
2.3 Example
#!/usr/bin/env python3 # -*- coding: utf-8 -*- # @Time : 2019/1/22 9:33 # @Author : Arrow and Bullet # @FileName: range_arange.py # @Software: PyCharm # @Blog ：/qq_41800366 from numpy import * #Introduce numpy A = arange(5) # Only end itemsprint(A) # Result [0 1 2 3 4] The result does not contain the end itemprint(type(A)) # Result <class ''> A = arange(1, 5) # The starting point is 1, the step size is 1 by defaultprint(A) # Results [1 2 3 4] A = arange(1, 5, 2) # The default step size is 2print(A) # Results [1 3] A = arange(1, 5.2, 0.6) # Floating point parameters may not be fully consistentprint(A) # result [1. 1.6 2.2 2.8 3.4 4. 4.6 5.2]
Summarize
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