Hi All
I am trying to use the round function on some columns of a dataframe while
leaving others unchanged. I wish to specify those columns to leave
unchanged.
My attempt is below - here, I would like the column d3 to be left but
columns d1, d2 and d4 to be rounded to 0 decimal places. I would welcome any
suggestions for a nicer way of doing this.
d1= rnorm(10,10)
d2= rnorm(10,6)
d3= rnorm(10,2)
d4= rnorm(10,-4)
d = data.frame(d1,d2,d3,d4)
x= NULL
for (i in 1:ncol(d)){
if (colnames(d)[i] =="d3"){x[i] = d[i]
} else { x[i] = round(d[i])}
out = do.call(cbind,x)
}
colnames(out) = colnames(d)
Thanks and regards
Pete
--
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If you can specify the omitted columns as numbers there is a quick way to do it. e.g.> dd1 d2 d3 d4 1 9.586524 4.833417 0.8142588 -3.237877 2 11.481521 6.536360 2.3361894 -4.042314 3 10.243192 5.506440 2.0443788 -3.478543 4 9.969548 6.159666 3.0449121 -4.827746 5 9.193832 4.085796 3.0176759 -2.199658 6 10.821571 5.442870 1.2630331 -3.483939 7 9.288714 5.756906 1.2432079 -4.387761 8 8.258251 7.729755 0.9170335 -5.416554 9 10.371080 6.234921 2.4462774 -4.433582 10 9.378106 5.389561 4.0592613 -3.433946> out <- d > out[-3] <- round(d[-3]) > outd1 d2 d3 d4 1 10 5 0.8142588 -3 2 11 7 2.3361894 -4 3 10 6 2.0443788 -3 4 10 6 3.0449121 -5 5 9 4 3.0176759 -2 6 11 5 1.2630331 -3 7 9 6 1.2432079 -4 8 8 8 0.9170335 -5 9 10 6 2.4462774 -4 10 9 5 4.0592613 -3>If you want to specify the column names as a character vector, this is almost as easy. e.g.> omit <- c("d1", "d3") > leave <- match(omit, names(d)) > out <- d > out[-leave] <- round(d[-leave]) > outd1 d2 d3 d4 1 9.586524 5 0.8142588 -3 2 11.481521 7 2.3361894 -4 3 10.243192 6 2.0443788 -3 4 9.969548 6 3.0449121 -5 5 9.193832 4 3.0176759 -2 6 10.821571 5 1.2630331 -3 7 9.288714 6 1.2432079 -4 8 8.258251 8 0.9170335 -5 9 10.371080 6 2.4462774 -4 10 9.378106 5 4.0592613 -3>Bill Venables ________________________________________ From: r-help-bounces at r-project.org [r-help-bounces at r-project.org] On Behalf Of Pete B [Peter.Brecknock at bp.com] Sent: 15 January 2011 14:53 To: r-help at r-project.org Subject: [R] Rounding variables in a data frame Hi All I am trying to use the round function on some columns of a dataframe while leaving others unchanged. I wish to specify those columns to leave unchanged. My attempt is below - here, I would like the column d3 to be left but columns d1, d2 and d4 to be rounded to 0 decimal places. I would welcome any suggestions for a nicer way of doing this. d1= rnorm(10,10) d2= rnorm(10,6) d3= rnorm(10,2) d4= rnorm(10,-4) d = data.frame(d1,d2,d3,d4) x= NULL for (i in 1:ncol(d)){ if (colnames(d)[i] =="d3"){x[i] = d[i] } else { x[i] = round(d[i])} out = do.call(cbind,x) } colnames(out) = colnames(d) Thanks and regards Pete -- View this message in context: http://r.789695.n4.nabble.com/Rounding-variables-in-a-data-frame-tp3218729p3218729.html Sent from the R help mailing list archive at Nabble.com. ______________________________________________ R-help at r-project.org mailing list https://stat.ethz.ch/mailman/listinfo/r-help PLEASE do read the posting guide http://www.R-project.org/posting-guide.html and provide commented, minimal, self-contained, reproducible code.
Hi Pete, Here is one option. The first part of sapply() just serves to get all names of d except those you excluded in 'exc'. If you were including fewer variables than you were excluding, just get rid of the logical ! operator. d <- data.frame(d1 = rnorm(10, 10), d2 = rnorm(10, 6), d3 = rnorm(10, 2), d4 = rnorm(10, -4)) exc <- "d3" cbind(d[, exc, drop = FALSE], sapply(names(d)[!names(d) %in% exc], function(x) round(d[, x]))) HTH, Josh On Fri, Jan 14, 2011 at 8:53 PM, Pete B <Peter.Brecknock at bp.com> wrote:> > Hi All > > I am trying to use the round function on some columns of a dataframe while > leaving others unchanged. I wish to specify those columns to leave > unchanged. > > My attempt is below - here, I would like the column d3 to be left but > columns d1, d2 and d4 to be rounded to 0 decimal places. I would welcome any > suggestions for a nicer way of doing this. > > d1= rnorm(10,10) > d2= rnorm(10,6) > d3= rnorm(10,2) > d4= rnorm(10,-4) > > d = data.frame(d1,d2,d3,d4) > > x= NULL > for (i in 1:ncol(d)){ > ?if (colnames(d)[i] =="d3"){x[i] = d[i] > ?} else { x[i] = round(d[i])} > ?out = do.call(cbind,x) > } > > colnames(out) = colnames(d) > > Thanks and regards > > Pete > -- > View this message in context: http://r.789695.n4.nabble.com/Rounding-variables-in-a-data-frame-tp3218729p3218729.html > Sent from the R help mailing list archive at Nabble.com. > > ______________________________________________ > R-help at r-project.org mailing list > https://stat.ethz.ch/mailman/listinfo/r-help > PLEASE do read the posting guide http://www.R-project.org/posting-guide.html > and provide commented, minimal, self-contained, reproducible code. >-- Joshua Wiley Ph.D. Student, Health Psychology University of California, Los Angeles http://www.joshuawiley.com/