Dear R helpers I have a dataframe as df = data.frame(x = c(1, 14, 3, 21, 11), y = c(102, 500, 40, 101, 189))> dfx y 1 1 102 2 14 500 3 3 40 4 21 101 5 11 189 # Actually I am having dataframe having multiple columns. I am just giving an example. I need to subtract all the rows of df by the first row of df i.e. I need to subtract each element of 'x' column by 1. Likewise I need to subtract all elements of column 'y' by 11. Thus I need an output like> df_newx y 1 0 0 2 13 398 3 2 -62 4 20 -1 5 10 87 As I had mentioned above, I have number of columns in reality and thus I can't use the command say df_new = data.frame(x = df$x-df$x[1], y = df$y-df$y[1]) Kindly guide Thanking you all in advance Regards Vincy [[alternative HTML version deleted]]
Hi:> df = data.frame(x = c(1, 14, 3, 21, 11), y = c(102, 500, 40, 101, 189)) > apply(df, 2, function(x) x - x[1])x y [1,] 0 0 [2,] 13 398 [3,] 2 -62 [4,] 20 -1 [5,] 10 87 HTH, Dennis On Tue, Jan 25, 2011 at 1:20 AM, Vincy Pyne <vincy_pyne@yahoo.ca> wrote:> Dear R helpers > > I have a dataframe as > > df = data.frame(x = c(1, 14, 3, 21, 11), y = c(102, 500, 40, 101, 189)) > > > df > x y > 1 1 102 > 2 14 500 > 3 3 40 > 4 21 101 > 5 11 189 > > # Actually I am having dataframe having multiple columns. I am just giving > an example. > > I need to subtract all the rows of df by the first row of df i.e. I need to > subtract each element of 'x' column by 1. Likewise I need to subtract all > elements of column 'y' by 11. Thus I need an output like > > > df_new > x y > 1 0 0 > 2 13 398 > 3 2 -62 > 4 20 -1 > 5 10 87 > > As I had mentioned above, I have number of columns in reality and thus I > can't use the command > say > > df_new = data.frame(x = df$x-df$x[1], y = df$y-df$y[1]) > > Kindly guide > > Thanking you all in advance > > Regards > > Vincy > > > > [[alternative HTML version deleted]] > > > ______________________________________________ > 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. > >[[alternative HTML version deleted]]
Hi, Try this: df_new <- as.data.frame(lapply(df, FUN=function(x) x-x[1])) I hope it works! Ivan Le 1/25/2011 10:20, Vincy Pyne a ?crit :> Dear R helpers > > I have a dataframe as > > df = data.frame(x = c(1, 14, 3, 21, 11), y = c(102, 500, 40, 101, 189)) > >> df > x y > 1 1 102 > 2 14 500 > 3 3 40 > 4 21 101 > 5 11 189 > > # Actually I am having dataframe having multiple columns. I am just giving an example. > > I need to subtract all the rows of df by the first row of df i.e. I need to subtract each element of 'x' column by 1. Likewise I need to subtract all elements of column 'y' by 11. Thus I need an output like > >> df_new > x y > 1 0 0 > 2 13 398 > 3 2 -62 > 4 20 -1 > 5 10 87 > > As I had mentioned above, I have number of columns in reality and thus I can't use the command > say > > df_new = data.frame(x = df$x-df$x[1], y = df$y-df$y[1]) > > Kindly guide > > Thanking you all in advance > > Regards > > Vincy > > > > [[alternative HTML version deleted]] > > > > ______________________________________________ > 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.-- Ivan CALANDRA PhD Student University of Hamburg Biozentrum Grindel und Zoologisches Museum Abt. S?ugetiere Martin-Luther-King-Platz 3 D-20146 Hamburg, GERMANY +49(0)40 42838 6231 ivan.calandra at uni-hamburg.de ********** http://www.for771.uni-bonn.de http://webapp5.rrz.uni-hamburg.de/mammals/eng/1525_8_1.php
On 2011-01-25 01:20, Vincy Pyne wrote:> Dear R helpers > > I have a dataframe as > > df = data.frame(x = c(1, 14, 3, 21, 11), y = c(102, 500, 40, 101, 189)) > >> df > x y > 1 1 102 > 2 14 500 > 3 3 40 > 4 21 101 > 5 11 189 > > # Actually I am having dataframe having multiple columns. I am just giving an example. > > I need to subtract all the rows of df by the first row of df i.e. I need to subtract each element of 'x' column by 1. Likewise I need to subtract all elements of column 'y' by 11. Thus I need an output like > >> df_new > x y > 1 0 0 > 2 13 398 > 3 2 -62 > 4 20 -1 > 5 10 87 > > As I had mentioned above, I have number of columns in reality and thus I can't use the command > say > > df_new = data.frame(x = df$x-df$x[1], y = df$y-df$y[1]) > > Kindly guideYou've already had good simple solutions. Here's one more, using the plyr package: require(plyr) df_new <- colwise(.fun = function(x) {x - x[1]})(df) plyr is very handy for all sorts of data manipulations. Peter Ehlers> > Thanking you all in advance > > Regards > > Vincy > > > > [[alternative HTML version deleted]] >
Try this: sweep(as.matrix(df), 2, as.matrix(df[1,])) On Tue, Jan 25, 2011 at 7:20 AM, Vincy Pyne <vincy_pyne@yahoo.ca> wrote:> Dear R helpers > > I have a dataframe as > > df = data.frame(x = c(1, 14, 3, 21, 11), y = c(102, 500, 40, 101, 189)) > > > df > x y > 1 1 102 > 2 14 500 > 3 3 40 > 4 21 101 > 5 11 189 > > # Actually I am having dataframe having multiple columns. I am just giving > an example. > > I need to subtract all the rows of df by the first row of df i.e. I need to > subtract each element of 'x' column by 1. Likewise I need to subtract all > elements of column 'y' by 11. Thus I need an output like > > > df_new > x y > 1 0 0 > 2 13 398 > 3 2 -62 > 4 20 -1 > 5 10 87 > > As I had mentioned above, I have number of columns in reality and thus I > can't use the command > say > > df_new = data.frame(x = df$x-df$x[1], y = df$y-df$y[1]) > > Kindly guide > > Thanking you all in advance > > Regards > > Vincy > > > > [[alternative HTML version deleted]] > > > ______________________________________________ > 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 [[alternative HTML version deleted]]