[R] evaluating string variables

[Berton Gunter]

Given my own language inadequacies (I speak only one), I must, of necessity,
refrain from criticizing  the multilingual. However, in this one instance my
sensibilities have been overwhelmed: "symmetric" , please :-)   .

Incidentally, you may find that file.path() is also useful.

Cheers,
Bert

-- Bert Gunter
Genentech Non-Clinical Statistics
South San Francisco, CA
 
"The business of the statistician is to catalyze the scientific learning
process."  - George E. P. Box
 
 

> -----Original Message-----
> From: r-help-bounces at stat.math.ethz.ch 
> [mailto:r-help-bounces at stat.math.ethz.ch] On Behalf Of 
> Leonardo Sepulveda Durán
> Sent: Friday, August 12, 2005 7:44 AM
> To: r-help at stat.math.ethz.ch
> Subject: [R] evaluating string variables
> 
> Hello!!!
> 
> I have a folder (C:/R/) with matrix files, named by number, i.e.
> 0.mat, 1.mat,...,1250.mat. In this case, they are 5x5 simetric
> matrices. I would like to compute a property for each matrix and put
> calculated values into a data frame for posterior ploting and
> printing. Below there is an example for 7 matrices (0.mat..6.mat)
> 
> #define data frame
> L <- data.frame(frame=numeric(7), L=numeric(7))
> f0<-1/(5*(5-1)) # first variable for computation
> 
> #loop over matrices, Open it , calculate property and put 
> into data frame
> for(i in 0:6){
> 	m<-matrix(scan('C:/R/i.mat', n=5*5),5,5, byrow=TRUE) # 
> load matrix
> 	f1<-geodist(m)                                          
>                  
> 	f2<-sum(colSums(f1$gdist))                              
>           
> 	l <-f0*f2                                               
>              
>        # Calculate property
> 	L[i+1, ]<-c(i,l)                                        
>              
>       # Fill data frame
> }
> 
> but the matrix cannot be loaded, because it try to open a file named
> "i.mat". I don`t know how to loop with a counter named 'i', and use it
> to define the name of the file too. How can i do it? I have not found
> the way.
>  
> Leonardo
> 
> ______________________________________________
> R-help at stat.math.ethz.ch mailing list
> https://stat.ethz.ch/mailman/listinfo/r-help
> PLEASE do read the posting guide! 
> http://www.R-project.org/posting-guide.html
>