How to exclude values in column A based on quality flags in column B

I have a file with multiple columns, column A has dates, column B has values, and column C is marked with a 0 or 1 as a quality flag (1 = unacceptable quality, 0 = acceptable quality). I need to average the data from column B based on sample date in column A, and change all the unacceptable quality data as a NaNs. I am not sure how to change change those column B values into NaNs using the quality flags of column C. Sorry if this is confusing, still new at this!

Answer 1

[Sai Sri Pathuri]

Following code may help.

You can use readtable/readmatrix to read the file into matlab. Consider X be the matrix containing A,B,C as first,second and third columns respectively. You may set the values of B to NaN using column C values as:

X(X(:,3)==0,2) = nan;