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From |
"Sutton, Bennett W." <BSutton@imf.org> |

To |
"statalist@hsphsun2.harvard.edu" <statalist@hsphsun2.harvard.edu> |

Subject |
st: RE: RE: RE: AW: Decimal Precision with Destring |

Date |
Mon, 19 Apr 2010 13:55:17 -0400 |

I'm not so sure. The values I have in my stata string variable "pcpie" match what I have in Excel. And if I calculate the growth rate using those values: . gen double test = ( 121.777007050082/116.477290339629-1)*100 . format test %20.0g . list pcpie test if year >= 2007 & year <= 2008 & ifscode == 313 | pcpie test | |-----------------------------------------------| 1064. | 116.47729033962900000000 4.5499999999998986 | 1065. | 121.77700705008200000000 4.5499999999998986 | +-----------------------------------------------+ I get a number that rounds down to 4.5. Ben -----Original Message----- From: owner-statalist@hsphsun2.harvard.edu [mailto:owner-statalist@hsphsun2.harvard.edu] On Behalf Of Nick Cox Sent: Monday, April 19, 2010 1:36 PM To: statalist@hsphsun2.harvard.edu Subject: st: RE: RE: AW: Decimal Precision with Destring I think your main problem is upstream, i.e. Excel is rounding -pcpie-, so nothing in Stata can put the lost digits back for you. Note that decimal precision is not really the issue, as Stata is necessarily holding _binary_ approximations. Nick n.j.cox@durham.ac.uk Sutton, Bennett W. Martin, Owing to the greater expertise of you and Nick, I have repeated two suggestions from you and found that in fact Stata is specifying the precision to 15 decimals, but now have a better understanding of my problem: * note pcpie is str19 .destring pcpie, gen(test1) force .format test1 %20.0g .gen double test2 = real(pcpie) .format test2 %20.0g Indeed I am getting the precision to 15 decimal places. .list year pcpie test1 test2 if year >= 2007 & year <= 2008 & ifscode == 313 | year pcpie test1 test2 | |----------------------------------------------------------------------| 1161. | 2007 116.477290339629000 116.47729033962899 116.47729033962899 | 1162. | 2008 121.777007050082000 121.77700705008201 121.77700705008201 | However note that test1 and test2 have decimal precision that does not exist in the string variable (pcpie). On account of this when I calculate a percent change of the of test1 and test2 I am getting results that round up to 4.6 instead of down to 4.5 in year 2008. .gen pch1 = (test1/L1.test1-1)*100 .format pch1 %20.0g .gen pch2 = (test2/L1.test2-1)*100 .format pch2 %20.0g .list year pcpie pch1 pch2 if year >= 2007 & year <= 2008 & ifscode == 313 | year pcpie pch1 pch2 | |----------------------------------------------------------------------| 1161. | 2007 116.477290339629000 2.8499999046325684 2.8499999046325684 | 1162. | 2008 121.777007050082000 4.5500001907348633 4.5500001907348633 | Note: taking the growth rate of numbers in pcpie you get a number that rounds down to 4.5. I know these are insanely small hairs to be splitting, but unfortunately this work is going into a publication and I need to make sure that the rounded result will be 4.5 and not 4.6. (not just here but in many, many other calculations.) Martin Weiss "Neither option you've sent are working for me." What does "not working" mean? Note the FAQ... Sutton, Bennett I'm using stata SE 10. Is there a setting somewhere which may be controlling the default decimal precision? Martin Weiss -destring- seems to work as well: ************* clear* inp str17 myvar 2.343541098765432 2.398784389359001 3.219439049039405 3.199038538208222 end destring myvar, gen(mynewvar) format mynewvar %18.0g l, noo ************* Martin Weiss This code does seem to work, using your second approach: ************* clear* inp str17 myvar 2.343541098765432 2.398784389359001 3.219439049039405 3.199038538208222 end list, noo gen double mynewvar=real(myvar) format mynewvar %18.0g l, noo ************* Sutton, Bennett W. I found one post on this from 5 years ago. But no resolution to the issue was posted. Wondering if anyone has since encountered and surmounted this problem: I am insheet-ing a .csv file with decimal precision set at 15 places in excel. But after insheeting into stata, the series are data type double, but only have precision to 10 places. I'm working with hyperinflation countries and the lack of precision is producing some incorrect results in calculations. I have also tried reading the data in as string variables which at least preserves the 15 digit precision, but destring-ing the data results in loss of precision again to 10 decimal places. * * For searches and help try: * http://www.stata.com/help.cgi?search * http://www.stata.com/support/statalist/faq * http://www.ats.ucla.edu/stat/stata/ * * For searches and help try: * http://www.stata.com/help.cgi?search * http://www.stata.com/support/statalist/faq * http://www.ats.ucla.edu/stat/stata/

**Follow-Ups**:**Re: st: RE: RE: RE: AW: Decimal Precision with Destring***From:*Maarten buis <maartenbuis@yahoo.co.uk>

**References**:**Re: st: Composite Indicator of Multidimensional Poverty***From:*amatoallah ouchen <at.ouchen@gmail.com>

**Re: st: Composite Indicator of Multidimensional Poverty***From:*Maarten buis <maartenbuis@yahoo.co.uk>

**st: Decimal Precision with Destring***From:*"Sutton, Bennett W." <BSutton@imf.org>

**st: AW: Decimal Precision with Destring***From:*"Martin Weiss" <martin.weiss1@gmx.de>

**st: AW: AW: Decimal Precision with Destring***From:*"Martin Weiss" <martin.weiss1@gmx.de>

**st: RE: AW: AW: Decimal Precision with Destring***From:*"Sutton, Bennett W." <BSutton@imf.org>

**st: AW: RE: AW: AW: Decimal Precision with Destring***From:*"Martin Weiss" <martin.weiss1@gmx.de>

**st: RE: AW: Decimal Precision with Destring***From:*"Sutton, Bennett W." <BSutton@imf.org>

**st: RE: RE: AW: Decimal Precision with Destring***From:*"Nick Cox" <n.j.cox@durham.ac.uk>

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