在Python中计算x1/x2的逐元素反正切,并正确选择象限
选择象限的方法是,arctan2(x1, x2) 是以原点为起点,经过点(1,0)的射线与以原点为起点,经过点(x2, x1)的射线之间所成的有符号弧度角。
第一个参数是y坐标,第二个参数是x坐标。如果x1.shape != x2.shape,则它们必须可广播到一个共同的形状。该方法返回一个弧度角数组,范围在[-pi, pi]。如果x1和x2都是标量,则返回标量。
步骤
首先,导入所需的库:
import numpy as np
使用array()方法创建数组。这些是不同象限的四个点:
x = np.array([-1, +1, +1, -1]) y = np.array([-1, -1, +1, +1])
显示array1:
print("Array1 (x coordinates)...\n", x)
显示array2:
print("\nArray2 (y coordinates)...\n", y)
为了计算x1/x2的逐元素反正切并正确选择象限,请在Python中使用numpy的arctan2()方法:
print("\nResult...",np.arctan2(y, x) * 180 / np.pi)
示例
import numpy as np # The quadrant is chosen so that arctan2(x1, x2) is the signed angle in radians between the ray # ending at the origin and passing through the point (1,0), and the ray ending at the origin and # passing through the point (x2, x1). # Creating arrays using the array() method # These are four points in different quadrants x = np.array([-1, +1, +1, -1]) y = np.array([-1, -1, +1, +1]) # Display the array1 print("Array1 (x coordinates)...\n", x) # Display the array2 print("\nArray2 (y coordinates)...\n", y) # To compute element-wise arc tangent of x1/x2 choosing the quadrant correctly, use the numpy, arctan2() method in Python print("\nResult...",np.arctan2(y, x) * 180 / np.pi)
输出
Array1 (x coordinates)... [-1 1 1 -1] Array2 (y coordinates)... [-1 -1 1 1] Result... [-135. -45. 45. 135.]
广告