Dear all, I have a dataframe with a column representing the names of the elements (a, b, etc) and one with their frequencies. How can I plot the frequencies so that each element has an associated frequency value? I have been thinking of a histogram, but I have found it difficult to implement. I have tried the following: group <- c("a", "b", "c", "d", "e") freq <-c(1, 2, 2, 5, 3) df <- data.frame(group, freq, stringsAsFactors = FALSE) hist(df$freq) library(lattice) histogram( ~ df$group) histogram( ~ as.factor(df$group)) histogram(df$freq ~ as.factor(df$group)) hist(df$freq) returns a histogram in which the values 1 and 2 appear 3 times, the values 3 and 5 appear once and 4 never. This is not what I wanted; I want instead a graph telling me that a appears once, b twice etc. histogram( ~ df$group) gives the error: Error in hist.default(as.numeric(x), breaks = breaks, plot = FALSE, include.lowest = include.lowest, : negative length vectors are not allowed histogram( ~ as.factor(df$group)) and histogram(df$freq ~ as.factor(df$group)) report all groups on the x axis (that is good) but all at 20% level. What am I missing? Thank you. -- Best regards, Luigi
Hi, Is this what you are after? group <- c("a", "b", "c", "d", "e") freq <-c(1, 2, 2, 5, 3) x = rep(group, freq) barplot(table(x)) Cheers, Ben> On Jun 7, 2018, at 6:00 AM, Luigi Marongiu <marongiu.luigi at gmail.com> wrote: > > Dear all, > I have a dataframe with a column representing the names of the > elements (a, b, etc) and one with their frequencies. > How can I plot the frequencies so that each element has an associated > frequency value? > I have been thinking of a histogram, but I have found it difficult to > implement. I have tried the following: > > group <- c("a", "b", "c", "d", "e") > freq <-c(1, 2, 2, 5, 3) > df <- data.frame(group, freq, stringsAsFactors = FALSE) > hist(df$freq) > library(lattice) > histogram( ~ df$group) > histogram( ~ as.factor(df$group)) > histogram(df$freq ~ as.factor(df$group)) > > hist(df$freq) returns a histogram in which the values 1 and 2 appear 3 > times, the values 3 and 5 appear once and 4 never. This is not what I > wanted; I want instead a graph telling me that a appears once, b twice > etc. > > histogram( ~ df$group) gives the error: > Error in hist.default(as.numeric(x), breaks = breaks, plot = FALSE, > include.lowest = include.lowest, : > negative length vectors are not allowed > > histogram( ~ as.factor(df$group)) and histogram(df$freq ~ > as.factor(df$group)) report all groups on the x axis (that is good) > but all at 20% level. > > What am I missing? > Thank you. > > -- > Best regards, > Luigi > > ______________________________________________ > R-help at r-project.org 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. >Ben Tupper Bigelow Laboratory for Ocean Sciences 60 Bigelow Drive, P.O. Box 380 East Boothbay, Maine 04544 http://www.bigelow.org Ecological Forecasting: https://eco.bigelow.org/ [[alternative HTML version deleted]]
exactly! Thank you! but it is possible to do it with lattice? I might have an extra level of information, for instance super-group, and in that case, I could plot all the supergroup easily together. On Thu, Jun 7, 2018 at 12:48 PM Ben Tupper <btupper at bigelow.org> wrote:> > Hi, > > Is this what you are after? > > group <- c("a", "b", "c", "d", "e") > freq <-c(1, 2, 2, 5, 3) > x = rep(group, freq) > barplot(table(x)) > > Cheers, > Ben > > > > On Jun 7, 2018, at 6:00 AM, Luigi Marongiu <marongiu.luigi at gmail.com> wrote: > > Dear all, > I have a dataframe with a column representing the names of the > elements (a, b, etc) and one with their frequencies. > How can I plot the frequencies so that each element has an associated > frequency value? > I have been thinking of a histogram, but I have found it difficult to > implement. I have tried the following: > > group <- c("a", "b", "c", "d", "e") > freq <-c(1, 2, 2, 5, 3) > df <- data.frame(group, freq, stringsAsFactors = FALSE) > hist(df$freq) > library(lattice) > histogram( ~ df$group) > histogram( ~ as.factor(df$group)) > histogram(df$freq ~ as.factor(df$group)) > > hist(df$freq) returns a histogram in which the values 1 and 2 appear 3 > times, the values 3 and 5 appear once and 4 never. This is not what I > wanted; I want instead a graph telling me that a appears once, b twice > etc. > > histogram( ~ df$group) gives the error: > Error in hist.default(as.numeric(x), breaks = breaks, plot = FALSE, > include.lowest = include.lowest, : > negative length vectors are not allowed > > histogram( ~ as.factor(df$group)) and histogram(df$freq ~ > as.factor(df$group)) report all groups on the x axis (that is good) > but all at 20% level. > > What am I missing? > Thank you. > > -- > Best regards, > Luigi > > ______________________________________________ > R-help at r-project.org 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. > > > Ben Tupper > Bigelow Laboratory for Ocean Sciences > 60 Bigelow Drive, P.O. Box 380 > East Boothbay, Maine 04544 > http://www.bigelow.org > > Ecological Forecasting: https://eco.bigelow.org/ > > > > >-- Best regards, Luigi
also, with this approach, I need to re-arrange the data. Is it possible to work directly on a dataframe? On Thu, Jun 7, 2018 at 12:48 PM Ben Tupper <btupper at bigelow.org> wrote:> > Hi, > > Is this what you are after? > > group <- c("a", "b", "c", "d", "e") > freq <-c(1, 2, 2, 5, 3) > x = rep(group, freq) > barplot(table(x)) > > Cheers, > Ben > > > > On Jun 7, 2018, at 6:00 AM, Luigi Marongiu <marongiu.luigi at gmail.com> wrote: > > Dear all, > I have a dataframe with a column representing the names of the > elements (a, b, etc) and one with their frequencies. > How can I plot the frequencies so that each element has an associated > frequency value? > I have been thinking of a histogram, but I have found it difficult to > implement. I have tried the following: > > group <- c("a", "b", "c", "d", "e") > freq <-c(1, 2, 2, 5, 3) > df <- data.frame(group, freq, stringsAsFactors = FALSE) > hist(df$freq) > library(lattice) > histogram( ~ df$group) > histogram( ~ as.factor(df$group)) > histogram(df$freq ~ as.factor(df$group)) > > hist(df$freq) returns a histogram in which the values 1 and 2 appear 3 > times, the values 3 and 5 appear once and 4 never. This is not what I > wanted; I want instead a graph telling me that a appears once, b twice > etc. > > histogram( ~ df$group) gives the error: > Error in hist.default(as.numeric(x), breaks = breaks, plot = FALSE, > include.lowest = include.lowest, : > negative length vectors are not allowed > > histogram( ~ as.factor(df$group)) and histogram(df$freq ~ > as.factor(df$group)) report all groups on the x axis (that is good) > but all at 20% level. > > What am I missing? > Thank you. > > -- > Best regards, > Luigi > > ______________________________________________ > R-help at r-project.org 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. > > > Ben Tupper > Bigelow Laboratory for Ocean Sciences > 60 Bigelow Drive, P.O. Box 380 > East Boothbay, Maine 04544 > http://www.bigelow.org > > Ecological Forecasting: https://eco.bigelow.org/ > > > > >-- Best regards, Luigi