2.18. Exercise: Incomplete Data 2

In a scientific calculation, matrices are commonly used for data representation. Suppose you are given a matrix \((M\times N)\) where you need to calculate the average of all the real numbers in the matrix. However, there is a problem in the matrix and some of the values are corrupted and given as ‘NaN’ string (stands for not a number).
Write a program that skips the corrupted numbers and outputs the average of rest in the given matrix. 3 digits after the decimal point is enough for our calculation and you can use the built-in \(\color{purple}{\texttt{round()}}\) function for this purpose.

  • \(M\) and \(N\) can be any positive integer.

  • Assume that the list of lists of floats representing the matrix will be given to you in variable \(\texttt{R}\).

Hint: It is necessary to keep the count of uncorrepted data in the given matrix

Sample I/O:

Input:
R = [[0.139, 0.216, 'NaN', 0.163],
     [0.418, 0.335, 0.217, 0.419],
     [0.097, 0.252, 0.458, 0.384]]

Output:
0.282

Input:
R = [[0.855, 'NaN', 'NaN', 0.661],
     [0.713, 'NaN', 0.306, 0.805],
     ['NaN', 'NaN', 0.562, 0.1],
     ['NaN', 0.895, 0.132, 0.795],
     [0.453, 0.519, 0.662, 'NaN']]

Output:
0.574

Input:
R = [[0.464, 0.856, 'NaN', 0.126, 0.707],
     [0.822, 0.453, 0.941, 'NaN', 0.985],
     [0.535, 0.169, 'NaN', 0.334, 0.566],
     [0.136, 0.133, 0.513, 'NaN', 'NaN'],
     [0.054, 0.686, 0.19, 0.164, 0.737]]

Output:
0.479