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From |
Yu Xue <snowrain@gmail.com> |

To |
statalist@hsphsun2.harvard.edu |

Subject |
Re: st: Stata cannot do math? |

Date |
Thu, 19 May 2011 00:08:56 -0500 |

Thanks Joseph and Conor! float() works! Sorry that I did not notice that Stata FAQ. Conor, I think Mathematica deals with floating-point variables in a different way. I did not expect this issue with Stata. On Wed, May 18, 2011 at 7:20 PM, Conor Hughes <cbhughes@uchicago.edu> wrote: > Hi, > Stata can certainly do math, just not quite the same math you're used > to. This is an issue of floating point arithmetic. For example, > replace > count a == 100.1 > in your code with > count a == float(100.1) > > Click through the FAQ a bit, maybe starting here > http://www.stata.com/support/faqs/data/float.html, as well as any > introductory numerical analysis textbook to get a better idea of how > computer arithmetic works. > > - Conor > > On Wed, May 18, 2011 at 6:44 PM, Yu Xue <snowrain@gmail.com> wrote: >> >> Hi All, >> >> This may be a stupid question. Here are the command and Stata output: >> >> .set obs 50 >> .gen a=100.1 >> .count if a==100.1 >> 0 >> .tab a >> 100.1 >> .sum a >> variable obs mean s.d. min max >> a 50 100.1 0 100.1 100.1 >> .gen b=a-100 >> .tab b >> 0.0999985 >> >> So, Stata shows that a is equal to 100.1, but actually, it is equal to >> 100.0999985.... >> >> Can anyone explain to me what this is? Do I have to set precision when >> I do math in Stata? How to set precision? >> Thanks! >> >> Yu >> * >> * 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/ > * * 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/

**References**:**st: Stata cannot do math?***From:*Yu Xue <snowrain@gmail.com>

**Re: st: Stata cannot do math?***From:*Conor Hughes <cbhughes@uchicago.edu>

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