# [R] Histogram of character elements

Luigi Marongiu m@rong|u@|u|g| @end|ng |rom gm@||@com
Thu Jun 7 13:00:12 CEST 2018

```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 using 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 using 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 using r-project.org mailing list -- To UNSUBSCRIBE and more, see
> https://stat.ethz.ch/mailman/listinfo/r-help
> 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

```