Some NumPy Basic Functions

There are a substantial number of functions available through NumPy, much too numerous to go through here. However, this section will highlight the use of a few simple functions and give links to the NumPy documentation for commonly used mathematical functions.

The following example illustrates computing an average from a 2D array, read in using a NumPy function.

input.txt:

34 56 78 91
12 23 33 51
20 39 48 57

Code:

import numpy as np

filename = 'input.txt'
data = np.loadtxt(filename)
avg_data = np.average(data)
print(avg_data)

Output:

45.1666666667

Some Common Mathematical Operations:

• Average over all or parts of an array - average()
• Sum of the elements of an array - sum()
• Square Root of all elements - sqrt()
• Maximum over an array - max() or amax
• Minimum over an array - min() or amin()
• Standard deviation over all the elements of an array - std()
• Trigonometric Functions (expect angle in radians)
  • Sine Function sin()
  • Cosine Function - cos()
  • Tangent Function - tan()
• Change from Degrees (angle) to radians - deg2rad() or radians()