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
Hi again,
I'm sort of pre-coffee still, but does this do it? The data frame only has
one variable, a factor where the order of the levels is specified.
library(lattice)
group <- c("a", "b", "c", "d",
"e")
freq <- c(1, 2, 2, 5, 3)
x <- rep(group, freq)
df <- data.frame(group = factor(x, levels = c("d",
"a", "b", "c", "e")) )
histogram(~ group, data = df)
As far as super-grouping the answer is likely yes, but without details and an
example (and coffee) I'm at a loss. I suggest getting a your hands on a
copy of https://www.r-project.org/doc/bib/R-books_bib.html#R:Sarkar:2008
<https://www.r-project.org/doc/bib/R-books_bib.html#R:Sarkar:2008>
It's really worth it if you plan to spend time with lattice.
Cheers,
Ben
> On Jun 7, 2018, at 7:02 AM, Luigi Marongiu <marongiu.luigi at
gmail.com> wrote:
>
> 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
>
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]]
Thank you Ben, this also works! I have a copy of the Sarkar but, usually, I don't work with histograms. I'll brush it up, then. Best regards, Luigi On Thu, Jun 7, 2018 at 1:43 PM Ben Tupper <btupper at bigelow.org> wrote:> > Hi again, > > I'm sort of pre-coffee still, but does this do it? The data frame only has one variable, a factor where the order of the levels is specified. > > library(lattice) > group <- c("a", "b", "c", "d", "e") > freq <- c(1, 2, 2, 5, 3) > x <- rep(group, freq) > df <- data.frame(group = factor(x, levels = c("d", "a", "b", "c", "e")) ) > histogram(~ group, data = df) > > As far as super-grouping the answer is likely yes, but without details and an example (and coffee) I'm at a loss. I suggest getting a your hands on a copy of https://www.r-project.org/doc/bib/R-books_bib.html#R:Sarkar:2008 It's really worth it if you plan to spend time with lattice. > > Cheers, > Ben > > > On Jun 7, 2018, at 7:02 AM, Luigi Marongiu <marongiu.luigi at gmail.com> wrote: > > 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 > > > 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