Nanda in partly correct but missed zero values.
"0" is zero
values of 1 to 7 is rounded to 4
and values of 8 to infinity are rounded to the nearest multiple of 5.
this rounding scheme was the outcome of much negotiation with the census bureau's
as far as individual tables it is the rows that all rounded independently of each other
total. this is explained in chapter 5 of the CTPP Electronic Guidebook. The beta version
guidebook (a cd) is available by contacting Nanda Srinivasan at
"Srinivasan, Nanda" wrote:
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
SF 3, being a standard product of the decennial census, did not have any rounding.
Sent: Monday, July 28, 2003 12:59 PM
Subject: [CTPP] Rounding and Totalling in CTPP Part 1 Data
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 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
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