Re: [CTPP] Rounding and Totalling in CTPP Part 1 Data

Peter, All numbers in CTPP are rounded. The rounding rules are as follows: Any number from 0-7 is rounded to 4. Any other number is rounded to the nearest 5. Totals in tables are rounded independently of the cells, so cell values may not add up to the total. SF 3, being a standard product of the decennial census, did not have any rounding. Nandu -----Original Message----- From: peter(a)caliper.com Sent: Monday, July 28, 2003 12:59 PM To: ctpp-news(a)chrispy.net Subject: [CTPP] Rounding and Totalling in CTPP Part 1 Data All: Has anyone else noticed that the values for counts in the CTPP Part 1 data always seem to be rounded to multiples of 5 (except for 5 itself, which usually seems to be 4)? Also, it seems that the total for a variable rarely is the sum of the other values for that variable. For example: - If you add up the individual means of transportation, only coincidentally will they add up to the total of all means of transportation, using the Both Sexes fields in Table 1-002 - When you look at the same data in SF 3, the values are close but different, clearly not rounded to multiples of 5 and definitely adding up to the expected total (in this case, All Workers) Peter ---------------------------------------------------------------- Peter Van Demark Director of GIS Products and Training Phone: 617-527-4700 Caliper Corporation Fax: 617-527-5113 1172 Beacon Street E-mail: peter(a)caliper.com Newton MA 02461-9926 Web site: http://www.caliper.com