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From |
"Terra Curtis" <terra.curtis@cambridgefinance.com> |

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

Subject |
st: RE: RE: Bracket [ ] notation |

Date |
Wed, 10 Aug 2005 10:28:22 -0400 |

Is there any way to tell Stata to ignore the command when at least one of the referenced entries does not exist? -----Original Message----- From: owner-statalist@hsphsun2.harvard.edu [mailto:owner-statalist@hsphsun2.harvard.edu] On Behalf Of Nick Cox Sent: Tuesday, August 09, 2005 5:09 PM To: statalist@hsphsun2.harvard.edu Subject: st: RE: Bracket [ ] notation If the subscript on the RHS is missing (meaning not present in the dataset), the result on the LHS will be missing too (meaning "missing"). Here the use of -by:- is just a detail and does not affect the principle. The principle can be seen by sysuse auto di mpg[0] di mpg[75] As advised in another thread, you would surely be better off re-casting this using time-series operators. Nick n.j.cox@durham.ac.uk P.S. the spelling is Stata. Terra Curtis > I am running into some problems trying to run a nonlinear regression. > I continue to get error 480 "starting values invalid or some RHS > variables have missing values." I think I see where my error is but > I'm not sure how STATA deals with a reference, say 'by varname: > data[x]' if x is out of the range of data for that varname. Here is > my code: I have written a program to specify the nonlinear equation, > and that is where the error is: > > program nlstk2_depreciation > version 8.1 > if "`1'" == "?" { > global S_1 "B3 B4 B5 drd2 dmktg2" > global B3=1 > global B4=1 > global B5=1 > global drd2=0.15 > global dmktg2=0.15 > exit > } > forvalues x=10/53 { > by coname: replace `1'=$B3+$B4*(ireal46[`x'] + > (1-$drd2)*ireal46[`x'-1] + (1-$drd2)^2*ireal46[`x'-2] + > (1-$drd2)^3*ireal46[`x'-3] + (1-$drd2)^4*ireal46[`x'-4] + > (1-$drd2)^5*ireal46[`x'-5] + (1-$drd2)^6*ireal46[`x'-6] + > (1-$drd2)^7*ireal46[`x'-7]+ (1-$drd2)^8*ireal46[`x'-8] + > (1-$drd2)^9*ireal46[`x'-9]/$drd2) + $B5*(imktg[`x'] + > (1-$dmktg2)*imktg[`x'-1] + (1-$dmktg2)^2*imktg[`x'-2] + > (1-$dmktg2)^3*imktg[`x'-3] + (1-$dmktg2)^4*imktg[`x'-4] + > (1-$dmktg2)^5*imktg[`x'-5] + (1-$dmktg2)^6*imktg[`x'-6] + > (1-$dmktg2)^7*imktg[`x'-7] + (1-$dmktg2)^8*imktg[`x'-8] + > (1-$dmktg2)^9*imktg[`x'-9]/$dmktg2) if `x'==year > } > end > > I have panel data for companies over a period of years, although each > company has a different amount of years of data (no company has more > than 53 years of data). If a company has 10 years of data, I want the > regression to use all 10 years of data. If it has more than 10 years > of data, I want it to use the most recent 10 (say, years 1990-1999), > then use the next 10 (years 1989-1998), and so on until it gets to the > last set of 10 years for that company. I think the logic of the > equation I have written works out, so I'm guessing the error is coming > from some referencing problem in the brackets...I don't quite > understand how STATA would deal with ireal46[49] if some company > didn't have a 49th ireal46 entry. > * * For searches and help try: * http://www.stata.com/support/faqs/res/findit.html * http://www.stata.com/support/statalist/faq * http://www.ats.ucla.edu/stat/stata/ * * For searches and help try: * http://www.stata.com/support/faqs/res/findit.html * http://www.stata.com/support/statalist/faq * http://www.ats.ucla.edu/stat/stata/

**References**:**st: RE: Bracket [ ] notation***From:*"Nick Cox" <n.j.cox@durham.ac.uk>

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