Erase row based on a specific condition in Matlab

I have a cell array with 10000 rows and 7 columns.

A={ 701  1999  53,7  701  407  31  18
702  1999  39,6  []  []  []  []
729  1999  48,6  729  2000  40  []
734  1999  70,6  []  []  []  []
745  1999  60,9  730  2000  13  [] }

I would like to erase the rows that have a blank entry in the 4th column. So I would get:

A={ 701  1999  53,7  701  407  31  18
729  1999  48,6  729  2000  40  []
745  1999  60,9  730  2000  13  [] }

Thank you

Answer 1

[Sean de Wolski]

idx = cellfun(@isempty,C(:,4));
A = A(~idx,:)

or

A(idx,:) = []