Python中的 numpy.geomspace()

numpy.geomspace()用于返回在对数尺度上均匀分布的数字（几何级数）。
这类似于 numpy.logspace() 但直接指定端点。每个输出样本都是前一个的常数倍。

Syntax : numpy.geomspace(start, stop, num=50, endpoint=True, dtype=None)
Parameters : 
start : [scalar] The starting value of the sequence. 
stop : [scalar] The final value of the sequence, unless endpoint is False. In that case, num + 1 values are spaced over the interval in log-space, of which all but the last (a sequence of length num) are returned. 
num : [integer, optional] Number of samples to generate. Default is 50. 
endpoint : [boolean, optional] If true, stop is the last sample. Otherwise, it is not included. Default is True. 
dtype : [dtype] The type of the output array. If dtype is not given, infer the data type from the other input arguments.
Return : 
samples : [ndarray] num samples, equally spaced on a log scale. 
 

代码#1：工作

Python

# Python3 Program demonstrate
# numpy.geomspace() function
 
import numpy as geek
 
 
print("B\n", geek.geomspace(2.0, 3.0, num = 5), "\n")
 
# To evaluate sin() in long range
point = geek.geomspace(1, 2, 10)
print("A\n", geek.sin(point))

输出 ：

B
 [ 2.          2.21336384  2.44948974  2.71080601  3.        ] 

A
 [ 0.84147098  0.88198596  0.91939085  0.95206619  0.9780296   0.9948976
  0.99986214  0.98969411  0.96079161  0.90929743]

代码 #2：numpy.geomspace() 的图形表示

Python

# Graphical Representation of numpy.geomspace()
import numpy as geek
import pylab as p
% matplotlib inline 
 
# Start = 1
# End = 3
 
# Samples to generate = 10
x1 = geek.geomspace(1, 3, 10, endpoint = False)
y1 = geek.ones(10)
   
p.plot(x1, y1, '+')

输出 ：