R help - Jan 2009 - problem with rbind

Hi All,

I have a problem with rbind.
I have data that consist of weight height .. etc of 1000 patients. I would
like to find the mean and the standard deviation ( for the weight , height
etc)  for each gender.


data<-read.table("data.txt", header=T, sep='\t')
fdata=NULL

for (i in 1:50){

nn<-names(X)[i]

m<-tapply(X[,i],data$gender,mean,na.rm=T)
s<-tapply(X[,i], data$gender, sd,na.rm=T)

p<-cbind(mean=m,sd.dev=s)

cn<-paste(nn,colnames(p),sep="_")
 
colnames(p)<-cn


fdata<-rbind(fdata,p)
} 
write.table(fdata, ?results.txt?,sep=?\t?,quote=FALSE, col.names=T)


here is the problem, 
1.	I have a header for each table but only the first one is printed.
2.	the weight_mean is suppose to be on the top of the means but it appears
on the top of the first column ( with no tab before the header)

weight_mean    weight_sd.dev 
F  14.33333  4.932883 
M  34.66667 10.692677 
F  35.00000  7.071068 
M  34.66667 10.692677 
.
.
.

I want the result to look like this with a line separating each table and
each table has a header

       weight_mean    weight_sd.dev 
 F 14.33333  4.932883 
M 34.66667 10.692677 

   hight_mean    hight_sd.dev
F 35.00000  7.071068 
M 34.66667 10.692677 

3.Is there a way to make a title for each table, for example
       
                    weight
    weight_mean    weight_sd.dev 
 F 14.33333  4.932883 
M 34.66667 10.692677 



I appreciate your help,


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Hi
> data<-read.table("data.txt", header=T, sep='\t')
Error in file(file, "r") : cannot open the connection
In addition: Warning message:
In file(file, "r") : cannot open file 'data.txt': No such file
or
directory

gives me an error so it is not possible to reproduce your function.

However it looks like work for lapply, sapply, by or similar

see e.g.
lapply(split(iris[,1:4], iris$Species), function(x) cbind(mean(x), sd(x)))
by(iris[,1:4], iris$Species, function(x) cbind(mean(x), sd(x)))

Regards
Petr


r-help-bounces at r-project.org napsal dne 21.01.2009 06:07:40:
> 
> Hi All,
> 
> I have a problem with rbind.
> I have data that consist of weight height .. etc of 1000 patients. I 
would
> like to find the mean and the standard deviation ( for the weight , 
height
> etc)  for each gender.
> 
> 
> data<-read.table("data.txt", header=T, sep='\t')
> fdata=NULL
> 
> for (i in 1:50){
> 
> nn<-names(X)[i]
> 
> m<-tapply(X[,i],data$gender,mean,na.rm=T)
> s<-tapply(X[,i], data$gender, sd,na.rm=T)
> 
> p<-cbind(mean=m,sd.dev=s)
> 
> cn<-paste(nn,colnames(p),sep="_")
> 
> colnames(p)<-cn
> 
> 
> fdata<-rbind(fdata,p)
> } 
> write.table(fdata, ?results.txt?,sep=?\t?,quote=FALSE, col.names=T)
> 
> 
> here is the problem, 
> 1.   I have a header for each table but only the first one is printed.
> 2.   the weight_mean is suppose to be on the top of the means but it 
appears
> on the top of the first column ( with no tab before the header)
> 
> weight_mean    weight_sd.dev 
> F  14.33333  4.932883 
> M  34.66667 10.692677 
> F  35.00000  7.071068 
> M  34.66667 10.692677 
> .
> .
> .
> 
> I want the result to look like this with a line separating each table 
and
> each table has a header
> 
>        weight_mean    weight_sd.dev 
>  F 14.33333  4.932883 
> M 34.66667 10.692677 
> 
>    hight_mean    hight_sd.dev
> F 35.00000  7.071068 
> M 34.66667 10.692677 
> 
> 3.Is there a way to make a title for each table, for example
> 
>                     weight
>     weight_mean    weight_sd.dev 
>  F 14.33333  4.932883 
> M 34.66667 10.692677 
> 
> 
> 
> I appreciate your help,
> 
> 
> -- 
> View this message in context: http://www.nabble.com/problem-with-rbind-
> tp21577241p21577241.html
> Sent from the R help mailing list archive at Nabble.com.
> 
> ______________________________________________
> R-help at r-project.org mailing list
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> PLEASE do read the posting guide 
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> and provide commented, minimal, self-contained, reproducible code.