Digital Signal Processing (DSP) with Python Programming

A Few Functions of Python®

To get function documentation, use .__doc__, e.g. print(range.__doc__), or help, e.g. help(zeros) or help(’def’), or ?, e.g. range.count?

• – def: introduces a function definition
• – if, else, elif: an if statement consists of a Boolean expression followed by one or more statements
• – for: executes a sequence of statements multiple times
• – while: repeats a statement or group of statements while a given condition is true
• – 1j or complex: returns complex value, e.g. a=1.3+1j*0.2 or a=complex(1.3,0.2)

Methods:

• – type A=array([0,4,12,3]), then type A. and tab, it follows a lot of methods, e.g. the argument of the maximum using A.argmax. For help type, e.g. A.dot?.

Functions:

• – int: converts a number or string to an integer
• – len: returns the number of items in a container
• – range: returns an object that produces a sequence of integers
• – type: returns the object type

From numpy:

• – abs: returns the absolute value of the argument
• – arange: returns evenly spaced values within a given interval
• – argwhere: finds the indices of array elements that are non-zero, grouped by element
• – array: creates an array
• – cos, sin, tan: respectively calculate the cosine, the sine and the tangent
• – cosh: calculates the hyperbolic cosine
• – cumsum: calculates the cumulative sum of array elements
• – diff: calculates the n-th discrete difference along a given axis
• – dot: product of two arrays
• – exp, log: respectively calculate the exponential, the logarithm
• – fft: calculates the ...