# Finding the Mean of a Specific Set of Columns

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## Finding the Mean of a Specific Set of Columns

 I am having trouble finding the mean of a specific part of my dataset. Here is a sample of it: plot lai leaf 1 104 82 1 2 104 167 2 3 104 248 3 4 104 343 4 5 104 377 5 6 105 64 1 7 105 139 2 8 105 211 3 9 105 296 4 10 105 348 5 11 106 94 1 12 106 167 2 13 106 243 3 14 106 281 4 15 106 332 5 16 108 83 1 17 108 382 2 18 108 320 3 19 108 146 4 20 108 129 5 I have many different plot numbers, none of which follow any kind of specific numeric sequence (even though I have sorted them from smallest to largest). I need to take the average (mean) of the LAI for each plot, and was wondering if there was a way to specify the code to do this. For example: I need the average of all the LAI measurements for each leaf of plot 104, 105, etc. Any help would be appreciated. Thanks! Get Outlook for iOS         [[alternative HTML version deleted]] ______________________________________________ [hidden email] mailing list -- To UNSUBSCRIBE and more, see https://stat.ethz.ch/mailman/listinfo/r-helpPLEASE do read the posting guide http://www.R-project.org/posting-guide.htmland provide commented, minimal, self-contained, reproducible code.
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## Re: Finding the Mean of a Specific Set of Columns

 Hi, try library("dplyr") plot <- c(104, 104 ,104 ,104 ,104 ,105 ,105 ,105 ,105 ,105,106,   106,106,  106,  106,108,  108,108,108,108) lai <- c(82, 167, 248, 343, 377, 64, 139, 211, 296, 348,          94, 167,243,281,332,83, 382,320,146,129) leaf <- c(1,2, 3,4,5,1,2,3,4,5,1,2,3,4,5,1,2,3,4,5) df <- cbind(plot, lai, leaf) %>% data.frame() df %>% dplyr::group_by(plot) %>%         dplyr::summarise(mean = mean(lai, na.rm = T)) Best, Frederick -----Original Message----- From: R-help [mailto:[hidden email]] On Behalf Of Isaac Barnhart Sent: donderdag 14 februari 2019 15:32 To: [hidden email] Subject: [R] Finding the Mean of a Specific Set of Columns I am having trouble finding the mean of a specific part of my dataset. Here is a sample of it: plot lai leaf 1 104 82 1 2 104 167 2 3 104 248 3 4 104 343 4 5 104 377 5 6 105 64 1 7 105 139 2 8 105 211 3 9 105 296 4 10 105 348 5 11 106 94 1 12 106 167 2 13 106 243 3 14 106 281 4 15 106 332 5 16 108 83 1 17 108 382 2 18 108 320 3 19 108 146 4 20 108 129 5 I have many different plot numbers, none of which follow any kind of specific numeric sequence (even though I have sorted them from smallest to largest). I need to take the average (mean) of the LAI for each plot, and was wondering if there was a way to specify the code to do this. For example: I need the average of all the LAI measurements for each leaf of plot 104, 105, etc. Any help would be appreciated. Thanks! Get Outlook for iOS         [[alternative HTML version deleted]] ______________________________________________ [hidden email] mailing list -- To UNSUBSCRIBE and more, see https://stat.ethz.ch/mailman/listinfo/r-helpPLEASE do read the posting guide http://www.R-project.org/posting-guide.htmland provide commented, minimal, self-contained, reproducible code. ______________________________________________ [hidden email] mailing list -- To UNSUBSCRIBE and more, see https://stat.ethz.ch/mailman/listinfo/r-helpPLEASE do read the posting guide http://www.R-project.org/posting-guide.htmland provide commented, minimal, self-contained, reproducible code.
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## Re: Finding the Mean of a Specific Set of Columns

 In reply to this post by ihb Hi Isaac, I am sure you will get lots of answers to this. Here is one using the dplyr package. Assuming that your data frame is called 'a', then library(dplyr) b <- dplyr::group_by(a,plot) %>% dplyr::summarise( mean(lai) ) b # A tibble: 4 x 2    plot `mean(lai)`         1   104        243. 2   105        212. 3   106        223. 4   108        212 HTH, Eric On Thu, Feb 14, 2019 at 6:20 PM Isaac Barnhart <[hidden email]> wrote: > I am having trouble finding the mean of a specific part of my dataset. > Here is a sample of it: > > plot lai leaf > 1 104 82 1 > 2 104 167 2 > 3 104 248 3 > 4 104 343 4 > 5 104 377 5 > 6 105 64 1 > 7 105 139 2 > 8 105 211 3 > 9 105 296 4 > 10 105 348 5 > 11 106 94 1 > 12 106 167 2 > 13 106 243 3 > 14 106 281 4 > 15 106 332 5 > 16 108 83 1 > 17 108 382 2 > 18 108 320 3 > 19 108 146 4 > 20 108 129 5 > > I have many different plot numbers, none of which follow any kind of > specific numeric sequence (even though I have sorted them from smallest to > largest). I need to take the average (mean) of the LAI for each plot, and > was wondering if there was a way to specify the code to do this. For > example: I need the average of all the LAI measurements for each leaf of > plot 104, 105, etc. Any help would be appreciated. Thanks! > > Get Outlook for iOS > >         [[alternative HTML version deleted]] > > ______________________________________________ > [hidden email] mailing list -- To UNSUBSCRIBE and more, see > 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]] ______________________________________________ [hidden email] mailing list -- To UNSUBSCRIBE and more, see https://stat.ethz.ch/mailman/listinfo/r-helpPLEASE do read the posting guide http://www.R-project.org/posting-guide.htmland provide commented, minimal, self-contained, reproducible code.
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## Re: Finding the Mean of a Specific Set of Columns

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## Re: Finding the Mean of a Specific Set of Columns

 In reply to this post by ihb On Feb 14, 2019, at 9:31 AM, Isaac Barnhart <[hidden email]> wrote: > > I am having trouble finding the mean of a specific part of my dataset. Here is a sample of it: > > plot lai leaf > 1 104 82 1 > 2 104 167 2 > 3 104 248 3 > 4 104 343 4 > 5 104 377 5 > 6 105 64 1 > 7 105 139 2 > 8 105 211 3 > 9 105 296 4 > 10 105 348 5 > 11 106 94 1 > 12 106 167 2 > 13 106 243 3 > 14 106 281 4 > 15 106 332 5 > 16 108 83 1 > 17 108 382 2 > 18 108 320 3 > 19 108 146 4 > 20 108 129 5 > > I have many different plot numbers, none of which follow any kind of specific numeric sequence (even though I have sorted them from smallest to largest). I need to take the average (mean) of the LAI for each plot, and was wondering if there was a way to specify the code to do this. For example: I need the average of all the LAI measurements for each leaf of plot 104, 105, etc. Any help would be appreciated. Thanks! Hi, This is easy using base R functions. See ?aggregate, ?by and ?tapply for a starting place. For example: > aggregate(lai ~ plot, data = DF, FUN = mean)   plot   lai 1  104 243.4 2  105 211.6 3  106 223.4 4  108 212.0 Regards, Marc Schwartz ______________________________________________ [hidden email] mailing list -- To UNSUBSCRIBE and more, see https://stat.ethz.ch/mailman/listinfo/r-helpPLEASE do read the posting guide http://www.R-project.org/posting-guide.htmland provide commented, minimal, self-contained, reproducible code.
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## Re: Finding the Mean of a Specific Set of Columns

 Thanks for the help! Isaac ________________________________ From: Marc Schwartz <[hidden email]> Sent: Thursday, February 14, 2019 11:05:23 AM To: Isaac Barnhart Cc: R-help Subject: Re: [R] Finding the Mean of a Specific Set of Columns On Feb 14, 2019, at 9:31 AM, Isaac Barnhart <[hidden email]> wrote: > > I am having trouble finding the mean of a specific part of my dataset. Here is a sample of it: > > plot lai leaf > 1 104 82 1 > 2 104 167 2 > 3 104 248 3 > 4 104 343 4 > 5 104 377 5 > 6 105 64 1 > 7 105 139 2 > 8 105 211 3 > 9 105 296 4 > 10 105 348 5 > 11 106 94 1 > 12 106 167 2 > 13 106 243 3 > 14 106 281 4 > 15 106 332 5 > 16 108 83 1 > 17 108 382 2 > 18 108 320 3 > 19 108 146 4 > 20 108 129 5 > > I have many different plot numbers, none of which follow any kind of specific numeric sequence (even though I have sorted them from smallest to largest). I need to take the average (mean) of the LAI for each plot, and was wondering if there was a way to specify the code to do this. For example: I need the average of all the LAI measurements for each leaf of plot 104, 105, etc. Any help would be appreciated. Thanks! Hi, This is easy using base R functions. See ?aggregate, ?by and ?tapply for a starting place. For example: > aggregate(lai ~ plot, data = DF, FUN = mean)   plot   lai 1  104 243.4 2  105 211.6 3  106 223.4 4  108 212.0 Regards, Marc Schwartz         [[alternative HTML version deleted]] ______________________________________________ [hidden email] mailing list -- To UNSUBSCRIBE and more, see https://stat.ethz.ch/mailman/listinfo/r-helpPLEASE do read the posting guide http://www.R-project.org/posting-guide.htmland provide commented, minimal, self-contained, reproducible code.