You need to provide an 'str(yarn)' so we can see what the structure is.  I
don't know what the 'pcr' program is expecting, but it looks like from what
you have provided that 'yarn' might be a dataframe and "X" is a vector.
Look at the documentation for pcr and see what it expects.

On Mon, May 10, 2010 at 9:08 PM, Ravi Ramaswamy <raramasw@gmail.com> wrote:

> Jim - thanks.
>
> It worked, however pcr program is still not accepting it.... there is a
> sample yarn data loaded and I am comparing.  My data looks like this
>
>
>               X1      X2      X3      X4      X5      X6      X7
> X8      X9     X10     X11     X12     X13     X14     X15     X16     X17
> 1Kalle   2.36038 2.35396 2.34772 2.34167 2.33587 2.33036 2.32517 2.32033
> 2.31583 2.31168 2.30791 2.30450 2.30150 2.29891 2.29680 2.29523 2.29421
>
> and yarn data looks like this
>
>       NIR.1   NIR.2   NIR.3   NIR.4   NIR.5   NIR.6   NIR.7   NIR.8
> NIR.9  NIR.10  NIR.11  NIR.12  NIR.13  NIR.14  NIR.15  NIR.16  NIR.17
> NIR.18
> 1   3.06630 3.08610 3.10790 3.09720 2.99790 2.82730 2.62330 2.40390 2.19310
> 2.00580 1.83790 1.69070 1.57770 1.50330 1.43810 1.33730 1.22060 1.14100
>
> So, I thought I could convert X1 to X.1 and it would work.  The names seem
> different.  Not sure how to make the change
>
> > names(yarn)
> [1] "NIR"     "density" "train"
>
> but
>
> > names(X)
>   [1] "X.1"   "X.2"   "X.3"   "X.4"   "X.5"   "X.6"   "X.7"   "X.8"
> "X.9"   "X.10"  "X.11"  "X.12"  "X.13"  "X.14"  "X.15"  "X.16"  "X.17"
> "X.18"
>
>
> On Mon, May 10, 2010 at 9:05 PM, jim holtman <jholtman@gmail.com> wrote:
>
>> Is this what you want:
>>
>> > x <- paste("X", 1:10, sep='')
>>
>> > x
>>  [1] "X1"  "X2"  "X3"  "X4"  "X5"  "X6"  "X7"  "X8"  "X9"  "X10"
>> > sub("X", "X.", x)
>>  [1] "X.1"  "X.2"  "X.3"  "X.4"  "X.5"  "X.6"  "X.7"  "X.8"  "X.9"  "X.10"
>> >
>>
>>
>>   On Mon, May 10, 2010 at 8:53 PM, Ravi Ramaswamy <raramasw@gmail.com>wrote:
>>
>>>  Hi - a newbie question, if someone can please help....
>>>
>>> I want to change X1, X2,,.....to X.1 X.2 etc in the names below.  I am
>>> using
>>> the Principal Component Regression function (pcr) and it seems to want it
>>> this way
>>>
>>> >  datap3.pcr <- pcr(water ~ X, 10, data = datap3, Validation ="cv")
>>> Error in model.frame.default(formula = water ~ X, data = datap3) :
>>>  invalid type (list) for variable 'X'
>>>
>>> ----------
>>>
>>> > names(X)
>>>  [1] "X1"   "X2"   "X3"   "X4"   "X5"   "X6"   "X7"   "X8"   "X9"   "X10"
>>> "X11"  "X12"  "X13"  "X14"  "X15"  "X16"  "X17"  "X18"  "X19"  "X20"
>>>  [21] "X21"  "X22"  "X23"  "X24"  "X25"  "X26"  "X27"  "X28"  "X29"
>>>  "X30"
>>> "X31"  "X32"  "X33"  "X34"  "X35"  "X36"  "X37"  "X38"  "X39"  "X40"
>>>  [41] "X41"  "X42"  "X43"  "X44"  "X45"  "X46"  "X47"  "X48"  "X49"
>>>  "X50"
>>> "X51"  "X52"  "X53"  "X54"  "X55"  "X56"  "X57"  "X58"  "X59"  "X60"
>>>  [61] "X61"  "X62"  "X63"  "X64"  "X65"  "X66"  "X67"  "X68"  "X69"
>>>  "X70"
>>> "X71"  "X72"  "X73"  "X74"  "X75"  "X76"  "X77"  "X78"  "X79"  "X80"
>>>  [81] "X81"  "X82"  "X83"  "X84"  "X85"  "X86"  "X87"  "X88"  "X89"
>>>  "X90"
>>> "X91"  "X92"  "X93"  "X94"  "X95"  "X96"  "X97"  "X98"  "X99"  "X100"
>>> > names(X)[1]
>>> [1] "X1"
>>> > for(i in 1:100){names(X)[i] <- "X.i"}
>>> > names(X)
>>>  [1] "X.i" "X.i" "X.i" "X.i" "X.i" "X.i" "X.i" "X.i" "X.i" "X.i" "X.i"
>>> "X.i" "X.i" "X.i" "X.i" "X.i" "X.i" "X.i" "X.i" "X.i" "X.i" "X.i" "X.i"
>>> "X.i"
>>>  [25] "X.i" "X.i" "X.i" "X.i" "X.i" "X.i" "X.i" "X.i" "X.i" "X.i" "X.i"
>>> "X.i" "X.i" "X.i" "X.i" "X.i" "X.i" "X.i" "X.i" "X.i" "X.i" "X.i" "X.i"
>>> "X.i"
>>>  [49] "X.i" "X.i" "X.i" "X.i" "X.i" "X.i" "X.i" "X.i" "X.i" "X.i" "X.i"
>>> "X.i" "X.i" "X.i" "X.i" "X.i" "X.i" "X.i" "X.i" "X.i" "X.i" "X.i" "X.i"
>>> "X.i"
>>>  [73] "X.i" "X.i" "X.i" "X.i" "X.i" "X.i" "X.i" "X.i" "X.i" "X.i" "X.i"
>>> "X.i" "X.i" "X.i" "X.i" "X.i" "X.i" "X.i" "X.i" "X.i" "X.i" "X.i" "X.i"
>>> "X.i"
>>>  [97] "X.i" "X.i" "X.i" "X.i"
>>> > for(i in 1:100){names(X)[i] <- X.i}
>>> Error: object 'X.i' not found
>>> > for(i in 1:100){names(X)[i] <- "X."i}
>>>
>>>        [[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<http://www.r-project.org/posting-guide.html>
>>> and provide commented, minimal, self-contained, reproducible code.
>>>
>>
>>
>>
>> --
>> Jim Holtman
>> Cincinnati, OH
>> +1 513 646 9390
>>
>> What is the problem that you are trying to solve?
>>
>
>


-- 
Jim Holtman
Cincinnati, OH
+1 513 646 9390

What is the problem that you are trying to solve?

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