# [R] Re: predict nlme syntax

Petr Pikal petr.pikal at precheza.cz
Fri May 20 09:10:53 CEST 2005

```Thank you. I somehow missed your answer and find it only after I
went through archives. I had to have partial blindfoldness when

Best regards
Petr Pikal

On 10 May 2005 at 13:24, r-help at stat.math.ethz.ch wrote:

> Dear all
>
> I would like to predict from nlme object for new data.
> I used predict(fit.nlme6, data=newdata) but I have always got
> fitted values, no matter how I changed newdata.
>
> I have
>
> > summary(fit.nlme6)
> Nonlinear mixed-effects model fit by maximum likelihood
>   Model: konverze ~ SSfpl(tepl, A, B, xmid, scal)
>  Data: limity.gr
>        AIC      BIC    logLik
>   882.4939 907.6738 -433.2469
>
> Random effects:
>  Formula: list(xmid ~ 1, scal ~ 1)
>  Level: spol.f
>  Structure: General positive-definite, Log-Cholesky
> parametrization
>          StdDev    Corr
> xmid     29.680114 xmid
> scal      6.481679 0.249
> Residual  2.168191
>
> Fixed effects: list(A ~ 1, B ~ 1, xmid ~ 1, scal ~ 1)
>         Value Std.Error  DF   t-value p-value
> A     36.1450  0.837050 154  43.18133       0
> B    101.0272  0.432074 154 233.81898       0
> xmid 735.3860  8.150964 154  90.22074       0
> scal  15.4453  2.201864 154   7.01466       0
>  Correlation:
>      A      B      xmid
> B    -0.088
> xmid  0.057 -0.088
> scal -0.089  0.469  0.036
>
> Standardized Within-Group Residuals:
>           Min            Q1           Med            Q3           Max
> -3.7707629568 -0.3291628536  0.0005885683  0.4020944158  3.7911729382
>
> Number of Observations: 172
> Number of Groups: 15
>
> where **tepl** is independent variable and **spol.f** is grouping
> factor.
>
> The newly constructed data frame newdata has the same structure
> of spol.f levels as has the limity.gr data frame used for fitting.
>
> > levels(limity.gr\$spol.f)
>  [1] "1.8/3"   "4/3"     "6.3/3"   "10.8/3"  "1.8/7"   "1.8/12"
> "1.8/30"  "6.3/30"  "10.8/30" "1.8/60"  "4/60"    "6.3/60"  "1.8/110"
> [14] "1.8/200" "1.8/300"
>
> > levels(newdata\$spol.f)
>  [1] "1.8/3"   "4/3"     "6.3/3"   "10.8/3"  "1.8/7"   "1.8/12"
> "1.8/30"  "6.3/30"  "10.8/30" "1.8/60"  "4/60"    "6.3/60"  "1.8/110"
> [14] "1.8/200" "1.8/300" >
>
> The only difference is in temperature.
>
> Please advice how shall I change newdata to be able to use it in
> predict function.

> The argument's name is newdata, not data.

> Thank you.
>
> Best regards
>
>

Petr Pikal
petr.pikal at precheza.cz

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