search for: tp3652352p3652432

Dear All, I am trying to analysis traffic data with one timestamp column and speed column. This data set contains six years data; for each year, I want to make a matrix in (day of the year) * (hour) 0 1 2 . . . 23 1 2 . . 365 However random day's record is missing(e.g. there are 40 missing records in 2005 data set), when I tried to use tapply function, matrix came out is