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 <rbarbarahc at 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]]
>
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--
Henrique Dallazuanna
Curitiba-Paran?-Brasil
25? 25' 40" S 49? 16' 22" O