Your lm args are wrong: Try this:
predict(lm(Dens_min ~ Velocity, dfTestes3sitesCriptic)) or predict(lm(Dens_min ~ Velocity_corrected, dfTestes3sitesCriptic)) On Fri, Mar 18, 2011 at 9:45 AM, barbara costa <rbarbar...@gmail.com> wrote: > Hello, > does anyone knows this predict is not resulting? > > # lm predict > dfTestes3sitesCriptic$Velocity_corrected <- ifelse > (dfTestes3sitesCriptic$Season == "A" & dfTestes3sitesCriptic$BeforeAfter == > "Before", (dfTestes3sitesCriptic$Velocity * mVel3ABefAfter), (ifelse > (dfTestes3sitesCriptic$Season == "Sp" & dfTestes3sitesCriptic$BeforeAfter == > "Before", (dfTestes3sitesCriptic$Velocity * mVel3SpBefAfter), > dfTestes3sitesCriptic$Velocity ))) > > dfTestes3sitesCriptic$Dens_min_corrected <- predict (lm( > dfTestes3sitesCriptic$Dens_min ~ dfTestes3sitesCriptic$Velocity, > dfTestes3sitesCriptic$Velocity_corrected)) > > > just for help: > Code_Site Year Season YearSeason Type_Environment BeforeAfter Species_Group > 31 PPBNoc 1998 A 1998-A Criptobenthic Before > Fish > 33 PPBNoc 1999 Sp 1999-Sp Criptobenthic Before > Fish > 35 PPBNoc 2009 A 2009-A Criptobenthic After > Fish > 37 PPBNoc 2009 Sp 2009-Sp Criptobenthic After > Fish > 39 PPBNoc 2010 A 2010-A Criptobenthic After > Fish > TransectTime_min TransectLenght_m Area_m2 Number Density Velocity > Dens_min > 31 15.00 55 55 89 1.62 3.67 > 5.93 > 33 15.00 55 55 50 0.91 3.67 > 3.33 > 35 18.15 45 45 185 4.11 2.48 > 10.20 > 37 10.23 45 45 92 2.04 4.40 > 9.00 > 39 16.92 45 45 251 5.58 2.66 > 14.84 > Code_Site2 Velocity_corrected > 31 TRUE 2.58 > 33 TRUE 3.25 > 35 TRUE 2.48 > 37 TRUE 4.40 > 39 TRUE 2.66 > > > > Thanks a lot. > Barbara > > [[alternative HTML version deleted]] > > ______________________________________________ > R-help@r-project.org mailing list > https://stat.ethz.ch/mailman/listinfo/r-help > PLEASE do read the posting guide http://www.R-project.org/posting-guide.html > and provide commented, minimal, self-contained, reproducible code. > -- Henrique Dallazuanna Curitiba-Paraná-Brasil 25° 25' 40" S 49° 16' 22" O ______________________________________________ R-help@r-project.org mailing list https://stat.ethz.ch/mailman/listinfo/r-help PLEASE do read the posting guide http://www.R-project.org/posting-guide.html and provide commented, minimal, self-contained, reproducible code.
