apjawor...@mmm.com wrote:
Thanks for the quick reply.
No, I did not run into any problems so far. I have been using the PLS
package and the modelling functions seem to work just fine.
In fact, even if I let the data.frame convert the x matrix to separate
column, the "y ~ x" modeling syntax still seems to work fine.
I don't see that behaviour:
rm (x) # make sure there is no leftover x in the workspace
mat <- matrix (1 : 9, 3)
df <- data.frame (y = 1 : 3, x = mat)
str (df)
df
coef (plsr (y ~ x, data = df, ncomp = 1)) # error
coef (plsr (y ~ x.1 + x.2 + x.3, data = df, ncomp = 1)) # works
df$x <- I (-mat)
str (df)
df
coef (plsr (y ~ x, data = df, ncomp = 1)) # works
Claudia
PS: May I be curious: what kind of data do you analyze with PLS?
Thanks again,
Andy
__________________________________
Andy Jaworski
518-1-01
Process Laboratory
3M Corporate Research Laboratory
-----
E-mail: apjawor...@mmm.com
Tel: (651) 733-6092
Fax: (651) 736-3122
From: Claudia Beleites <cbelei...@units.it>
To: apjawor...@mmm.com
Cc: r-help@r-project.org
Date: 03/12/2010 02:13 PM
Subject: Re: [R] Data frame question
Andy,
Did you run into any kind of trouble?
I'm asking because I'm maintaining a package for spectroscopic data that
heavily
uses "I (spectra.matrix)" ...
However, once you have the matrix safe inside the data.frame, you can
delete the
"AsIs":
> a <- matrix (1:9, 3)
> str (a)
int [1:3, 1:3] 1 2 3 4 5 6 7 8 9
> df <- data.frame (a = I (a))
> str (df)
'data.frame': 3 obs. of 1 variable:
$ a: 'AsIs' int [1:3, 1:3] 1 2 3 4 5 6 7 8 9
> df$a <- unclass (df$a)
> str (df)
'data.frame': 3 obs. of 1 variable:
$ a: int [1:3, 1:3] 1 2 3 4 5 6 7 8 9
> df$a
[,1] [,2] [,3]
[1,] 1 4 7
[2,] 2 5 8
[3,] 3 6 9
> dim (df)
[1] 3 1
However, I don't know whether something can now trigger a conversion to
data.frame that the AsIs would have stopped.
Cheers,
Claudia
apjawor...@mmm.com wrote:
> Hi,
>
> I have the following question about creating data frames. I want to
> create a data frame with 2 components: a vector and a matrix.
>
> Let me use a simple example:
>
> y <- rnorm(10)
> x <- matrix(rnorm(150), nrow=10)
>
> Now if I do
>
> dd <- data.frame(x=x, y=y)
>
> I get a data frame with 16 colums, but if, according to the
documentation,
> I do
>
> dd <- data.frame(x=I(x), y=y)
>
> then str(dd) gives:
>
> 'data.frame': 10 obs. of 2 variables:
> $ x: AsIs [1:10, 1:15] 0.700073.... -0.44371.... -0.46625....
> 0.977337.... 0.509786.... ...
> $ y: num 0.4676 -1.4343 -0.3671 0.0637 -0.231 ...
>
> This looks and works OK.
>
> Now, there exists a CRAN package called pls. It has a yarn data set in
> it.
>
>> data(yarn)
>> str(yarn)
> 'data.frame': 28 obs. of 3 variables:
> $ NIR : num [1:28, 1:268] 3.07 3.07 3.08 3.08 3.1 ...
> ..- attr(*, "dimnames")=List of 2
> .. ..$ : NULL
> .. ..$ : NULL
> $ density: num 100 80.2 79.5 60.8 60 ...
> $ train : logi TRUE TRUE TRUE TRUE TRUE TRUE ...
>
> This looks almost the same, except the matrix component in my example
has
> the AsIs instead of num.
>
> Is this just some older behavior of the data.frame function producing
this
> difference? If not, how can I get my data frame (dd) to look like yarn?
>
> I read the help pages for data.frame and as.data.frame and found this
> paragraph
>
> If a list is supplied, each element is converted to a column in the data
> frame. Similarly, each column of a matrix is converted separately. This
> can be overridden if the object has a class which has a method for
> as.data.frame: two examples are matrices of class "model.matrix" (which
> are included as a single column) and list objects of class "POSIXlt"
which
> are coerced to class "POSIXct".
>
> If I do
>
>> methods(as.data.frame)
> [1] as.data.frame.aovproj* as.data.frame.array
> [3] as.data.frame.AsIs as.data.frame.character
> [5] as.data.frame.complex as.data.frame.data.frame
> [7] as.data.frame.Date as.data.frame.default
> [9] as.data.frame.difftime as.data.frame.factor
> [11] as.data.frame.ftable* as.data.frame.integer
> [13] as.data.frame.list as.data.frame.logical
> [15] as.data.frame.logLik* as.data.frame.matrix
> [17] as.data.frame.model.matrix as.data.frame.numeric
> [19] as.data.frame.numeric_version as.data.frame.ordered
> [21] as.data.frame.POSIXct as.data.frame.POSIXlt
> [23] as.data.frame.raw as.data.frame.table
> [25] as.data.frame.ts as.data.frame.vector
>
> so it looks like there is a matrix method for as.data.frame. The
question
> then is how can I override the default behavior for the matrix object
> (converting columns separately).
>
>
> Any hint will be appreciated,
>
> Andy
>
>
> __________________________________
> Andy Jaworski
> 518-1-01
> Process Laboratory
> 3M Corporate Research Laboratory
> -----
> E-mail: apjawor...@mmm.com
> Tel: (651) 733-6092
> Fax: (651) 736-3122
> [[alternative HTML version deleted]]
>
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> PLEASE do read the posting guide
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> and provide commented, minimal, self-contained, reproducible code.
--
Claudia Beleites
Dipartimento dei Materiali e delle Risorse Naturali
Università degli Studi di Trieste
Via Alfonso Valerio 6/a
I-34127 Trieste
phone: +39 0 40 5 58-37 68
email: cbelei...@units.it
--
Claudia Beleites
Dipartimento dei Materiali e delle Risorse Naturali
Università degli Studi di Trieste
Via Alfonso Valerio 6/a
I-34127 Trieste
phone: +39 0 40 5 58-37 68
email: cbelei...@units.it
______________________________________________
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PLEASE do read the posting guide http://www.R-project.org/posting-guide.html
and provide commented, minimal, self-contained, reproducible code.
