[R] decimal separator from comma to dot

[Simon Zehnder]

Hi,

I think this could help you: https://stat.ethz.ch/pipermail/r-help/2008-January/152378.html

Best

Simon

On Aug 9, 2013, at 12:19 PM, maxbre <mbressan at arpa.veneto.it> wrote:

> This is my reproducible example
> 
> df<-structure(list(IDANT = c(37837L, 37838L, 37839L, 37840L, 37841L, 
> 37842L, 37843L, 40720L, 40721L, 40722L), N_TX = c(6L, 6L, 6L, 
> 4L, 1L, 1L, 1L, 2L, 2L, 1L), TILT = c(0L, 0L, 0L, 0L, 6L, 6L, 
> 6L, 0L, 0L, 0L), DIREZIONE = c(50L, 220L, 110L, 50L, 220L, 110L, 
> 50L, 170L, 70L, 270L), DATA_INI = structure(c(2L, 2L, 2L, 2L, 
> 2L, 2L, 2L, 1L, 1L, 1L), .Label = c("20/10/2004", "29/08/2002"
> ), class = "factor"), POT_TX = structure(c(4L, 4L, 4L, 3L, 2L, 
> 2L, 2L, 1L, 1L, 1L), .Label = c("10", "11,5", "4", "8"), class = "factor")),
> .Names = c("IDANT", 
> "N_TX", "TILT", "DIREZIONE", "DATA_INI", "POT_TX"), row.names = c(NA, 
> 10L), class = "data.frame")
> 
> The data frame “df” it’s a “simplified snapshot” from an oracle table
> imported via odbc (by using the package RODBC) ;
> now, the problem with the data frame “df” is that one variable “POT_TX” have
> the decimal separator formatted with comma instead of dot; 
> so I’m in the need to reformat the variable from factor to numeric type to
> perform some useful calculations
> 
> this is my code I worked so far
> 
> #function to change comma to dot
> myfun <- function(x) {sub(",",".",x)}
> 
> #apply the function to all variables
> new <- apply(df, 2, myfun )
> newdf <- data.frame(apply(new, 2, as.numeric))
> str(newdf)
> 
> #apply the function to one variables
> var<-as.numeric(sapply(df[,6], FUN=myfun))
> df$POT_TX<-var
> str(df)
> 
> 
> my questions:
> 
> 1.	is it possible to use the more convenient function “apply” with reference
> to just some variables and not all of them? I’ve been reading on the help
> that “Where X has named dimnames, it can be a character vector selecting
> dimension names.”, what does exactly means that?
> 
> 2.	do you know some more convenient methods to perform comma to dot
> substitution in just some selected variables of a data frame? To note that
> the desired final result is again a dataframe
> 
> 3.	do you know any workaround to set the decimal delimiter for a variable
> (field) “at the early steps” when connecting via odbc and then querying to
> the table?
> For these “early steps” I’ve been using something like:
> library(RODBC)
> con<-odbcConnect("dsn", uid="user", pwd="password")
> df<-sqlQuery(con, "select * from table.name;")
> 
> thank you all for the eventual support
> 
> 
> 
> 
> --
> View this message in context: http://r.789695.n4.nabble.com/decimal-separator-from-comma-to-dot-tp4673414.html
> Sent from the R help mailing list archive at Nabble.com.
> 
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