Re: [R] applying a function to data frame columns
Try this: sapply(names(u), function(x)u[x][u[x] =min(v[x]) u[x] = max(v[x])]) On 21/02/2008, dxc13 [EMAIL PROTECTED] wrote: useR's, I want to apply this function to the columns of a data frame: u[u = range(v)[1] u = range(v)[2]] where u is the n column data frame under consideration and v is a data frame of values with the same number of columns as u. For example, v1 - c(1,2,3) v2 - c(3,4,5) v3 - c(2,3,4) v - as.data.frame(cbind(v1,v2,v3)) uk1 - seq(min(v1) - .5, max(v1) + .5, .5) uk2 - seq(min(v2) - .5, max(v2) + .5, .5) uk3 - seq(min(v3) - .5, max(v3) + .5, .5) u - do.call(expand.grid, list(uk1,uk2,uk3)) Here, there are 3 columns; instead of hard-coding this, can the function given above, which will restrict the u data frame to values within the ranges of each variable, be done with the apply function? Thanks in advance. dxc13 -- View this message in context: http://www.nabble.com/applying-a-function-to-data-frame-columns-tp15619657p15619657.html Sent from the R help mailing list archive at Nabble.com. __ R-help@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. -- Henrique Dallazuanna Curitiba-Paraná-Brasil 25° 25' 40 S 49° 16' 22 O __ R-help@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.
Re: [R] applying a function to data frame columns
You can do:
lapply2(u, v, function(u,v) u[inRange(u, range(v))])
using two functions 'lapply2' and 'inRange' defined at bottom.
This basically does:
lapply(seq(along=u),
function(i, U, V){
u - U[[i]]
v - V[[i]]
u[u = range(v)[1] u = range(v)[2]]
},
U = u, V = v)
Tim Hesterberg
I want to apply this function to the columns of a data frame:
u[u = range(v)[1] u = range(v)[2]]
where u is the n column data frame under consideration and v is a data frame
of values with the same number of columns as u. For example,
v1 - c(1,2,3)
v2 - c(3,4,5)
v3 - c(2,3,4)
v - as.data.frame(cbind(v1,v2,v3))
uk1 - seq(min(v1) - .5, max(v1) + .5, .5)
uk2 - seq(min(v2) - .5, max(v2) + .5, .5)
uk3 - seq(min(v3) - .5, max(v3) + .5, .5)
u - do.call(expand.grid, list(uk1,uk2,uk3))
Here, there are 3 columns; instead of hard-coding this, can the function
given above, which will restrict the u data frame to values within the
ranges of each variable, be done with the apply function? Thanks in
advance.
dxc13
# inRange requires ifelse1, part of the splus2R package.
inRange - function(x, a, b, strict = FALSE) {
# Return TRUE where x is within the range of a to b.
# If a is length 2 and b is missing, assume that a gives the range.
# if(strict==FALSE), then allow equality, otherwise require a x b.
# strict may be a vector of length 2, governing the two ends.
if(length(a)==2) {
b - a[2]
a - a[1]
}
else if(length(a) * length(b) != 1)
stop(a and b must both have length 1, or a may have length 2)
strict - rep(strict, length=2)
ifelse1(strict[1], xa, x=a) ifelse1(strict[2], xb, x=b)
}
lapply2 - function(X1, X2, FUN, ...){
# Like lapply, but for two inputs.
# FUN should take two inputs, one from X1 and one from X2.
n1 - length(X1)
if(n1 != length(X2))
stop(X1 and X2 have different lengths)
if(is.character(FUN))
FUN - getFunction(FUN)
else if(!is.function(FUN)) {
farg - substitute(FUN)
if(is.name(farg))
FUN - getFunction(farg)
else
stop(', deparseText(farg), ' is not a function)
}
FUNi - function(i, X1, X2, FUN2, ...)
FUN2(X1[[i]], X2[[i]], ...)
# Create sequence vector.
# If objects have same names, use them.
i - seq(length = n1)
names1 - names(X1)
if(length(names1) identical(names1, names(X2)))
names(i) - names1
# Final result; loop over the sequence vector
lapply(i, FUNi, X1 = X1, X2 = X2, FUN2 = FUN, ...)
}
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Re: [R] applying a function to data frame columns
One thing is needed: names(v) - names(u) PS:Thanks Mark Leeds On 22/02/2008, Henrique Dallazuanna [EMAIL PROTECTED] wrote: Try this: sapply(names(u), function(x)u[x][u[x] =min(v[x]) u[x] = max(v[x])]) On 21/02/2008, dxc13 [EMAIL PROTECTED] wrote: useR's, I want to apply this function to the columns of a data frame: u[u = range(v)[1] u = range(v)[2]] where u is the n column data frame under consideration and v is a data frame of values with the same number of columns as u. For example, v1 - c(1,2,3) v2 - c(3,4,5) v3 - c(2,3,4) v - as.data.frame(cbind(v1,v2,v3)) uk1 - seq(min(v1) - .5, max(v1) + .5, .5) uk2 - seq(min(v2) - .5, max(v2) + .5, .5) uk3 - seq(min(v3) - .5, max(v3) + .5, .5) u - do.call(expand.grid, list(uk1,uk2,uk3)) Here, there are 3 columns; instead of hard-coding this, can the function given above, which will restrict the u data frame to values within the ranges of each variable, be done with the apply function? Thanks in advance. dxc13 -- View this message in context: http://www.nabble.com/applying-a-function-to-data-frame-columns-tp15619657p15619657.html Sent from the R help mailing list archive at Nabble.com. __ R-help@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. -- Henrique Dallazuanna Curitiba-Paraná-Brasil 25° 25' 40 S 49° 16' 22 O -- Henrique Dallazuanna Curitiba-Paraná-Brasil 25° 25' 40 S 49° 16' 22 O __ R-help@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.
