Often, certain data entries in a data set can be missing, corrupted, or invalid. Computers often assign such entries with value of NaN (which stands for not-a-number). In MATLAB, the NaN functions similarly to numbers. For example, you could create a MATLAB array [2:5 NaN 7 8]. To see an important attribute of NaN that is different than a number, type NaN == NaN into the command window and observe the result. The below steps require you to use MATLAB features that can be helpful when using data sets. Follow the steps below: Note: do not present any of the arrays in the command window unless requested.

Create a 2D data array using the lines below (write them exactly as written below):

rng(2); % line 1

A = randi(10,1000,1000); % line 2

A(randi(1e6,20,1)) = NaN; % line 3

Describe in words (in the command window) what line 3 in part a does.

Clearly present the indices of the columns of A which contain a NaN. Hint re-read the first paragraph of this problem.

Replace any element of A that is NaN with a 0.

Certain elements of A have the following characteristics: an even row number, an odd column number, and a value that is less than or equal to 5. Replace every element which has every listed attribute with a value of -41.

Clearly report the sum of the values in A (1 number) in the command window.