Displaying 10 results from an estimated 10 matches for "dftest".
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ftest
2011 May 10
1
Filtering out bad data points
Hi,
I always have a question about how to do this best in R. I have a data
frame and a set of criteria to filter points out. My procedure is to
always locate indices of those points, check if index vector length is
greater than 0 or not and then remove them. Meaning
dftest <- data.frame(x=rnorm(100),y=rnorm(100));
qtile <- quantile(dftest$x,probs=c(0.05,0.95));
badIdx <- which((dftest$x < qtile[1]) | (dftest$x > qtile[2]));
if (length(badIdx) > 0) {
dftest <- dftest[-idx,];
}
My question is that is there a more streamlined way to achieve thi...
2011 Oct 25
2
Logistic Regression - Variable Selection Methods With Prediction
...orward, Backward, All possible subsests. I am using
misclassification rate to pick the winner method.
This is what i have as of now,
Reg <- glm (Graduation ~., DFtrain,family=binomial(link="logit"))
step <- extractAIC(Reg, direction="forward")
pred <- predict(Reg, DFtest,type="response")
mis <- mean({pred > 0.5} != {DFtest[,"Graduation"] == "Y"})
This program actually works but I needed to check to make sure am
doing this right. Also, I am getting the same misclassification rates
for all different methods.
I also tried to use...
2012 May 01
3
Data frame vs matrix quirk: Hinky error message?
AdvisoRs:
Is the following a bug, feature, hinky error message, or dumb Bert?
> mtest <- matrix(1:12,nr=4)
> dftest <- data.frame(mtest)
> ix <- cbind(1:2,2:3)
> mtest[ix] <- NA
> mtest
[,1] [,2] [,3]
[1,] 1 NA 9
[2,] 2 6 NA
[3,] 3 7 11
[4,] 4 8 12
## But ...
> dftest[ix] <- NA
Error in `[<-.data.frame`(`*tmp*`, ix, value = NA) :
only logical mat...
2012 Jan 02
2
Conditionally adding a constant
I am trying to add a constant to the previous value of a variable based on
certain conditions. Maybe there is a simple way to do this that I am missing
completely. I have given an example below:
df <- data.frame(x = c(1,2,3,4,5), y = c(10,20,30,NA,NA))
> df
x y
1 1 10
2 2 20
3 3 30
4 4 NA
5 5 NA
I want to add 2 to the previous value of y, if x exceeds 3 (also will have
to handle NAs in
2012 Jun 28
1
add constraints to nls or use another function
...in advance for your help,
Have a good day,
Ptit Bleu.
-------------------------------------------------------------------------------------------------------------
#The experimental data :
http://r.789695.n4.nabble.com/file/n4634705/nlstest_data.txt
nlstest_data.txt
#The script
library(lattice)
dftest<-read.table("nlstest_data.txt", sep=";", dec=".", as.is=T, header=T)
nlsfit<-coefficients(nls(y ~
F+A*(x-1)+B*log(x)+C*(x-1)*(x-1)+D*log(x)*log(x), data=dftest, start =
list(A=-0.06,B=0.48,C=0.89,D=0.03,F=1), control=list(maxiter=200,
tol=0.01)))
# Coefficients...
2008 Mar 10
2
write.table with row.names=FALSE unnecessarily slow?
write.table with large data frames takes quite a long time
> system.time({
+ write.table(df, '/tmp/dftest.txt', row.names=FALSE)
+ }, gcFirst=TRUE)
user system elapsed
97.302 1.532 98.837
A reason is because dimnames is always called, causing 'anonymous' row
names to be created as character vectors. Avoiding this in
src/library/utils, along the lines of
Index: write.table.R
====...
2012 Sep 04
0
AFTREG weights
...1 0 3 0.643382 1
> 10 1 2 0 3 0.300433 1
> 11 2 3 0 3 0.666964 1
>
> with this function
>
> AftRegTD<-aftreg(Surv(StartTime,EndTime,Event)~Cov,dist="loglogistic",id=dfTest$IdObs,data=dfTest)
>
> Any suggestion to introduce "weights" as argument in aftreg function?
>
No, not for the moment, although it would be straightforward to add.
However, I am not sure that case weights is what you are seeking.
Göran
> Thanks,
> Francesca
>
--...
2004 Apr 20
0
strange result with contrasts
...-000mM -0.01972550 0.04288981 -0.4599111 6.473607e-01
dose050mM-000mM -0.12015983 0.05356935 -2.2430704 2.886726e-02 <- significant
dose100mM-000mM 0.01252061 0.04113846 0.3043529 7.619872e-01
A collegue of mine has run the same data through a SAS program (listed below)
proc glm data = dftest;
class dose time batch;
model value = dose|time|batch;
means dose / dunnett ('000mM');
lsmeans dose /pdiff singular=1;
run;
Giving the following p-values:
Pr(>|t|)
dose010mM-000mM 0.4047
dose025mM-000mM 0.6474
dose050m...
2013 Jul 24
3
Change values in a dateframe
Hello
I have the following problem :
The dataframe TEST has multiple lines for a same person because :
there are differents values of Nom or differents values of Prenom
but the values of Matricule or Sexe or Date.de.naissance are the same.
TEST <- structure(list(Matricule = c(66L, 67L, 67L, 68L, 89L, 90L, 90L,
91L, 108L, 108L, 108L), Nom = structure(c(1L, 2L, 2L, 4L, 8L,
5L, 6L, 9L, 3L, 3L,
2020 Jan 07
2
Network Diagnostics
In our smallest office, we have a Dell CentOS 7 system, a
Windows system and an HP 8610 printer, all hard-wire Ethernet
connected with a Linksys router. The router provides Internet
connection. All of the network-connected systems get their
IP address from the router at power up.
Successful network connection of the printer at power up
has recently started taking much longer than usual.? The