Re: [R] Inserting rows of interpolated data
Hi Why you do not change date and time to POSIX object? It is simple and saves you a lot of frustration when merging two data frames. If you changed lightdata date and time to new column lightdata$newdate - strptime(paste(lightdata$date, lightdata$time, sep= ), format = %d/%m/%y %H:%M:%S) generate empty empty -data.frame(newdate= seq(firstdate, lastdate, by=min), light=NA) see ?seq.POSIXt for details new - merge(lightdata, empty, by=newdate, all=TRUE) shall result in merged dataframes Regards Petr -Original Message- From: r-help-boun...@r-project.org [mailto:r-help-bounces@r- project.org] On Behalf Of Benstead, Jonathan Sent: Tuesday, February 12, 2013 12:19 AM To: r-help@r-project.org Subject: [R] Inserting rows of interpolated data Dear help list - I have light data with 5-min time-stamps. I would like to insert four 1-min time-stamps between each row and interpolate the light data on each new row. To do this I have come up with the following code: lightdata - read.table(Test_light_data.csv, header = TRUE, sep = ,) # read data file into object lightdata library(chron) mins - data.frame(times(1:1439/1440)) # generate a dataframe of 24 hours of 1-min timestamps Nth.delete - function(dataframe, n)dataframe[-(seq(n, to=nrow(dataframe), by=n)),] # function for deleting nth row empty - data.frame(1/9/13, Nth.delete(mins, 5), NA) # delete all 5-min timestamps in a new dataframe colnames(empty) - c(date, time, light) # add correct column name to empty timestamp dataframe newdata - rbind(lightdata, empty) I get the following error message: Warning message: In `[-.factor`(`*tmp*`, ri, value = c(0.000694, 0.00139, : invalid factor level, NAs generated Digging into this a little, I can see that the two time columns are doing what I need and APPEAR to be similar in format: head(lightdata) datetime light 1 1/9/13 0:00:00 -0.00040925 2 1/9/13 0:05:00 -0.00023386 3 1/9/13 0:10:00 -0.00032155 4 1/9/13 0:15:00 -0.00017539 5 1/9/13 0:20:00 -0.00029232 6 1/9/13 0:25:00 -0.00038002 head(empty) date time light 1 1/9/13 00:01:00NA 2 1/9/13 00:02:00NA 3 1/9/13 00:03:00NA 4 1/9/13 00:04:00NA 5 1/9/13 00:06:00NA 6 1/9/13 00:07:00NA but they clearly are not as far as R is concerned, as shown by str: str(lightdata) 'data.frame': 288 obs. of 3 variables: $ date : Factor w/ 1 level 1/9/13: 1 1 1 1 1 1 1 1 1 1 ... $ time : Factor w/ 288 levels 0:00:00,0:05:00,..: 1 2 3 4 5 6 7 8 9 10 ... $ light: num -0.000409 -0.000234 -0.000322 -0.000175 -0.000292 ... str(empty) 'data.frame': 1152 obs. of 3 variables: $ date : Factor w/ 1 level 1/9/13: 1 1 1 1 1 1 1 1 1 1 ... $ time :Class 'times' atomic [1:1152] 0.000694 0.001389 0.002083 0.002778 0.004167 ... .. ..- attr(*, format)= chr h:m:s $ light: Factor w/ 1 level NA: 1 1 1 1 1 1 1 1 1 1 ... In the first (original) dataframe, light is a factor, while in the dataframe of generated timestamps, the timestamps are actually still in fractions of a day. Presumably this is why rbind is not working? Can anyone help? By the way, I know I can use na.approx in zoo to do the eventual interpolation of the light data. It's getting there that has me stumped for now. Many thanks, Jon (new R user). __ 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. __ 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] Inserting rows of interpolated data
Hi Jon, zoo is great for tasks like this, not just for na.approx. :) I would approach the problem like this: library(zoo) # put lightdata into a zoo object z - with(lightdata, zoo(light, as.POSIXct(paste(date, time), format=%m/%d/%y %H:%M:%S))) # merge the above zoo object with an empty zoo # object that has all the index values you want Z - merge(z, zoo(,seq(start(z),end(z),by=1 min))) # interpolate between the 5-min observatoins Z - na.approx(Z) HTH, -- Joshua Ulrich | about.me/joshuaulrich FOSS Trading | www.fosstrading.com R/Finance 2013: Applied Finance with R | www.RinFinance.com On Mon, Feb 11, 2013 at 5:19 PM, Benstead, Jonathan jbenst...@as.ua.edu wrote: Dear help list - I have light data with 5-min time-stamps. I would like to insert four 1-min time-stamps between each row and interpolate the light data on each new row. To do this I have come up with the following code: lightdata - read.table(Test_light_data.csv, header = TRUE, sep = ,) # read data file into object lightdata library(chron) mins - data.frame(times(1:1439/1440)) # generate a dataframe of 24 hours of 1-min timestamps Nth.delete - function(dataframe, n)dataframe[-(seq(n, to=nrow(dataframe), by=n)),] # function for deleting nth row empty - data.frame(1/9/13, Nth.delete(mins, 5), NA) # delete all 5-min timestamps in a new dataframe colnames(empty) - c(date, time, light) # add correct column name to empty timestamp dataframe newdata - rbind(lightdata, empty) I get the following error message: Warning message: In `[-.factor`(`*tmp*`, ri, value = c(0.000694, 0.00139, : invalid factor level, NAs generated Digging into this a little, I can see that the two time columns are doing what I need and APPEAR to be similar in format: head(lightdata) datetime light 1 1/9/13 0:00:00 -0.00040925 2 1/9/13 0:05:00 -0.00023386 3 1/9/13 0:10:00 -0.00032155 4 1/9/13 0:15:00 -0.00017539 5 1/9/13 0:20:00 -0.00029232 6 1/9/13 0:25:00 -0.00038002 head(empty) date time light 1 1/9/13 00:01:00NA 2 1/9/13 00:02:00NA 3 1/9/13 00:03:00NA 4 1/9/13 00:04:00NA 5 1/9/13 00:06:00NA 6 1/9/13 00:07:00NA but they clearly are not as far as R is concerned, as shown by str: str(lightdata) 'data.frame': 288 obs. of 3 variables: $ date : Factor w/ 1 level 1/9/13: 1 1 1 1 1 1 1 1 1 1 ... $ time : Factor w/ 288 levels 0:00:00,0:05:00,..: 1 2 3 4 5 6 7 8 9 10 ... $ light: num -0.000409 -0.000234 -0.000322 -0.000175 -0.000292 ... str(empty) 'data.frame': 1152 obs. of 3 variables: $ date : Factor w/ 1 level 1/9/13: 1 1 1 1 1 1 1 1 1 1 ... $ time :Class 'times' atomic [1:1152] 0.000694 0.001389 0.002083 0.002778 0.004167 ... .. ..- attr(*, format)= chr h:m:s $ light: Factor w/ 1 level NA: 1 1 1 1 1 1 1 1 1 1 ... In the first (original) dataframe, light is a factor, while in the dataframe of generated timestamps, the timestamps are actually still in fractions of a day. Presumably this is why rbind is not working? Can anyone help? By the way, I know I can use na.approx in zoo to do the eventual interpolation of the light data. It's getting there that has me stumped for now. Many thanks, Jon (new R user). __ 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. __ 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] Inserting rows
Try this: rbind(df, matrix(0, 3, 3, dimnames = list(NULL, names(df On Fri, Oct 23, 2009 at 11:44 AM, Ashta sewa...@gmail.com wrote: Hi all, I have the data set df with three varaibles, x1 x2 x3 1 2 5 2 4 1 5 6 0 1 1 2 I want to insert more rows ( eg, 3 rows with value filled with zeros) 1 2 5 2 4 1 5 6 6 1 1 2 0 0 0 0 0 0 0 0 0 Can any body help me out? Thanks __ 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] Inserting rows
?rbind df1 - data.frame(matrix(rep(0,9),nrow=3)) names(df1) - c(x1,x2,x3) rbind(df,df1) --- On Fri, 10/23/09, Ashta sewa...@gmail.com wrote: From: Ashta sewa...@gmail.com Subject: [R] Inserting rows To: R help r-help@r-project.org Received: Friday, October 23, 2009, 9:44 AM Hi all, I have the data set df with three varaibles, x1 x2 x3 1 2 5 2 4 1 5 6 0 1 1 2 I want to insert more rows ( eg, 3 rows with value filled with zeros) 1 2 5 2 4 1 5 6 6 1 1 2 0 0 0 0 0 0 0 0 0 Can any body help me out? Thanks __ 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. __ Looking for the perfect gift? Give the gift of Flickr! http://www.flickr.com/gift/ __ 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.
