Python numpy.tan()用法及代码示例

numpy.tan(array [，out])= ufunc'tan')：此数学函数可帮助用户计算所有x(作为数组元素)的三角切线。

参数：

array    : [array_like]elements are in radians.
out      : [optional]shape same as array.  

2pi Radians = 360 degrees
tan(x) = sin(x) / cos(x)

返回：

An array with trignometric sine
of x for all x i.e. array elements 

代码1：工作

# Python program explaining 
# tan() function 
  
import numpy as np 
import math 
  
in_array = [0, math.pi / 4, 3*np.pi / 2, math.pi/6] 
print ("Input array : \n", in_array) 
  
tan_Values = np.tan(in_array) 
print ("\nTan values : \n", tan_Values)

输出：

Input array : 
 [0, 0.7853981633974483, 4.71238898038469, 0.5235987755982988]

Tan values : 
 [  0.00000000e+00   1.00000000e+00   5.44374645e+15   5.77350269e-01]

代码2：图形表示

# Python program showing 
# Graphical representation of  
# tan() function 
  
import numpy as np 
import matplotlib.pyplot as plt 
  
in_array = np.linspace(0, np.pi, 12) 
out_array = np.tan(in_array) 
  
print("in_array : ", in_array) 
print("\nout_array : ", out_array) 
  
# red for numpy.tan() 
plt.plot(in_array, out_array, color = 'red', marker = "o") 
plt.title("numpy.tan()") 
plt.xlabel("X") 
plt.ylabel("Y") 
plt.show()

输出：

in_array :  [ 0.          0.28559933  0.57119866  0.856798    1.14239733  1.42799666
  1.71359599  1.99919533  2.28479466  2.57039399  2.85599332  3.14159265]

out_array :  [  0.00000000e+00   2.93626493e-01   6.42660977e-01   1.15406152e+00
   2.18969456e+00   6.95515277e+00  -6.95515277e+00  -2.18969456e+00
  -1.15406152e+00  -6.42660977e-01  -2.93626493e-01  -1.22464680e-16]

参考文献：
https://docs.scipy.org/doc/numpy-dev/reference/generated/numpy.tan.html#numpy.tan
。