One way to do it is to start with string replacement.. to illustrate, say that the data file contains
4 5 6 7 8 9
1 2 Bad 4 5 6
Bad 7 8 9 10 11
0 Bad Bad Bad 4 5
then:
>> buffer = fileread('myData.txt') ;
>> buffer = strrep(buffer, 'Bad', 'NaN') ; % or regexprep().
>> sscanf(buffer, '%f', [6 4]).'
ans =
4 5 6 7 8 9
1 2 NaN 4 5 6
NaN 7 8 9 10 11
0 NaN NaN NaN 4 5
