[R] PLSR error

[Uwe Ligges]

On 13.05.2011 11:38, romzero wrote:
> Hi,
> this is my R-Script
>
> library(pls)
> file<- "C:\\TXT\\brix.txt"
> d<- as.matrix(read.table(file, header=T, sep=",", row.names = NULL))
> plsdata<- data.frame(NIR=c(1:nrow(X)))
> plsdata$NIR<- I(d[,3:603])
> plsdata$Brix<- d[,2]
> results<- plsr(Brix ~ NIR, data=plsdata)
>
> after the last string i have this error
>
>> results<- plsr(Brix ~ NIR, data=plsdata)
> Error in `[[<-.data.frame`(`*tmp*`, i, value = c(302053L, 305882L, 292704L,
> :
>    replacement has 448346 rows, data has 746
> In addition: Warning message:
> In model.matrix.default(mt, mf) : variable 'Brix' converted to a factor
>
> the data table have this structure
>> str(plsdata)
> 'data.frame':   746 obs. of  2 variables:
>   $ NIR : 'AsIs' chr [1:746, 1:601] "0.0011030396" "0.0013019324"
> "0.0005979965" "0.0012952804" ...
>    ..- attr(*, "dimnames")=List of 2
>    .. ..$ : NULL
>    .. ..$ : chr  "X1100.0" "X1102.0" "X1104.0" "X1106.0" ...
>   $ Brix: chr  "24.4" "24.8" "24.7" "20.1" ...


All your data are character rather than numeric. If you fo not transform 
the data.frame to a matrix at the very beginning after reading the 
data.frame, things should be fine, I guess (untested, since we do not 
have the data).

Uwe Ligges


> where am I wrong?
> thanks for help
>
>
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