Python numpy.logspace()
Python numpy.logspace()函数以对数刻度返回数字间距均匀的W.R.T间隔。
语法 :
numpy.logspace(start,
stop,
num = 50,
endpoint = True,
base = 10.0,
dtype = None)
参数 :
start : [float] 区间范围的开始(基数开始)。
stop : [float] 区间范围的结束(基本停止)。
endpoint : [boolean, optional]如果为真,停止是最后一个样本。默认情况下,为True
num : [int, optional] 要生成的样本数
base : [float, optional] 对数比例的基数。默认情况下,等于10.0
dtype : 输出阵列的类型
返回 :
ndarray
代码1:解释logspace()的使用
# Python Programming illustrating
# numpy.logspace method
import numpy as geek
# base = 11
print("B\n", geek.logspace(2.0, 3.0, num=5, base = 11))
# base = 10
print("B\n", geek.logspace(2.0, 3.0, num=5))
# base = 10, dtype = int
print("B\n", geek.logspace(2.0, 3.0, num=5, dtype = int))
输出 :
B
[ 121. 220.36039471 401.31159963 730.8527479 1331. ]
B
[ 100. 177.827941 316.22776602 562.34132519 1000. ]
B
[ 100 177 316 562 1000]
代码2:使用matplotlib模块pylab图形表示numpy.logspace()
# Graphical Representation of numpy.logspace()
import numpy as geek
import pylab as p
# Start = 0
# End = 2
# Samples to generate = 10
x1 = geek.logspace(0, 1, 10)
y1 = geek.zeros(10)
# Start = 0.1
# End = 1.5
# Samples to generate = 12
x2 = geek.logspace(0.1, 1.5, 12)
y2 = geek.zeros(12)
p.plot(x1, y1+0.05, 'o')
p.xlim(-0.2, 18)
p.ylim(-0.5, 1)
p.plot(x2, y2, 'x')
输出 :