-----Original Message-----
From: soniaamin5 at gmail.com
Sent: Mon, 20 Apr 2015 18:56:19 +0200
To: sarah.goslee at gmail.com
Subject: Re: [R] Problem with col
When I type data , I obtain all the numeric values and the headears I
added (Consommation,Cylindre,Puissance,Poids)
No you probably do not, as Sarah explained.
As a quick example of the issue look at the two data sets below. Just copy
and paste into your R editor. Both data sets are in dput() format which is
how you should supply sample data to R-help.
ddat1 <- structure(list(aa = structure(1:4, .Label = c("a", "b", "c",
"d"), class = "factor"), bb = 1:4), .Names = c("aa", "bb"), row.names =
c(NA,
-4L), class = "data.frame")
ddat2 <- structure(list(aa = c("a", "b", "c", "d"), bb = c("1", "2", "3",
"4")), .Names = c("aa", "bb"), row.names = c(NA, -4L), class = "data.frame")
If yo do
dat1
dat2
they look the same on the screen but if you do str() they are not the
same.
str(dat1)
str(dat2)
Also try
ddat1$bb * 5 #works
ddat2$bb * 5 # error!
They look the same on the computer screen but they are quite different.
John Kane
Kingston ON Canada
Thanks
2015-04-20 18:40 GMT+02:00 Sarah Goslee <sarah.goslee at gmail.com>:
What is the problem? One or more of your columns was read as factor, as
str(data)
would show you. To avoid this, you can add stringsAsFactors=FALSE to
the read.table command, but if you expect your data to be entirely
numeric then there's something wrong with it that you need to hunt
down.
Sarah
On Mon, Apr 20, 2015 at 12:33 PM, Sonia Amin <soniaamin5 at gmail.com>
wrote:
Dear All,
I have written the following lines:
data<-read.table("C:\\Users\\intel\\Documents\\SIIID\\datamultiplereg.txt",header
= FALSE, sep = "")
colnames(data)<-c("Consommation","Cylindre","Puissance","Poids")
result.model1<-lm(Consommation~Cylindre+Puissance+Poids, data=data)
summary(result.model1)
I obtained the following message:
Call:
lm(formula = Consommation ~ Cylindre + Puissance + Poids, data = data)
Residuals:
Error in quantile.default(resid) : factors are not allowed
In addition: warning message:
In Ops.factor(r, 2) :
?^? This is not relevant for factors
Where is the problem?
Thank you in advance
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