Re: [Gnuplot-info] ploting if a special character exist in the line

[Leo B. <l_b...@us...>]

   Another way is to use the string operator: stringcolumn(3) or the
   shorthand strcol(3). I should have seen that to start with.

Thanks, I wasn't aware of this. So you would use

plot "data.txt" u 1:(strcol($3) eq 'M' ? $2 : 1/0)

Leo