R help - Nov 2003 - Histogram

Hi,

I have what should be a simple question.  I would like to generate a
histogram of

x <-
c("a","b","c","b","c","c")

where the first bar to be labeled 'c' with height 3, second bar to be
labeled 'b' with height 2 and third bar to be labeled 'a' with
height 1.

This should be an easy task in R but I think I am missing something?

Thanks,
Arend van der Veen

On 18 Nov 2003, Arend P. van der Veen wrote:
> Hi,
> 
> I have what should be a simple question.  I would like to generate a
> histogram of
> 
> x <-
c("a","b","c","b","c","c")
> 
> where the first bar to be labeled 'c' with height 3, second bar to
be
> labeled 'b' with height 2 and third bar to be labeled 'a'
with height 1.
> 
> This should be an easy task in R but I think I am missing something?
> 
> Thanks,
> Arend van der Veen
> 
> ______________________________________________
> R-help at stat.math.ethz.ch mailing list
> https://www.stat.math.ethz.ch/mailman/listinfo/r-help
> 
You don't want a histogram, but a barplot:
barplot(table(x))

Uwe Ligges

Arend P. van der Veen wrote:
> Hi,
>
> I have what should be a simple question.  I would like to generate a
> histogram of
>
> x <-
c("a","b","c","b","c","c")
>
> where the first bar to be labeled 'c' with height 3, second bar to
be
> labeled 'b' with height 2 and third bar to be labeled 'a'
with height 1.
Maybe the following would help you:

x <-
c("a","b","c","b","c","c")
x.fac <- factor(x)
plot(x.fac)

Best Regards,
Ryota Suzuki
>
> This should be an easy task in R but I think I am missing something?
>
> Thanks,
> Arend van der Veen
>
> ______________________________________________
> R-help at stat.math.ethz.ch mailing list
> https://www.stat.math.ethz.ch/mailman/listinfo/r-help
>

plot(table(factor(x,levels=c("c","b","a"))))

is at least approximately what you want (the only complicated bit is 
reversing the order of the bars from the default alphabetical order)

substituting barplot() for plot() also works

you may want to use ylab="something" in the plot or barplot command to
get
a more descriptive axis label

On 18 Nov 2003, Arend P. van der Veen wrote:
> Hi,
> 
> I have what should be a simple question.  I would like to generate a
> histogram of
> 
> x <-
c("a","b","c","b","c","c")
> 
> where the first bar to be labeled 'c' with height 3, second bar to
be
> labeled 'b' with height 2 and third bar to be labeled 'a'
with height 1.
> 
> This should be an easy task in R but I think I am missing something?
> 
> Thanks,
> Arend van der Veen
> 
> ______________________________________________
> R-help at stat.math.ethz.ch mailing list
> https://www.stat.math.ethz.ch/mailman/listinfo/r-help
> 
-- 
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Zoology Department, University of Florida    http://www.zoo.ufl.edu/bolker
Box 118525                                   (ph)  352-392-5697
Gainesville, FL 32611-8525                   (fax) 352-392-3704

"Arend P. van der Veen" <apv at capital.net> writes:
> Hi,
> 
> I have what should be a simple question.  I would like to generate a
> histogram of
> 
> x <-
c("a","b","c","b","c","c")
> 
> where the first bar to be labeled 'c' with height 3, second bar to
be
> labeled 'b' with height 2 and third bar to be labeled 'a'
with height 1.
> 
> This should be an easy task in R but I think I am missing something?
That's not a histogram...

barplot(rev(table(x)))

will do it, or - allowing more general level shuffling - 

barplot(table(factor(x,levels=c("c","b","a"))))

or 

barplot(rev(sort(table(x))))

if you want the columns by decreasing frequency.

-- 
   O__  ---- Peter Dalgaard             Blegdamsvej 3  
  c/ /'_ --- Dept. of Biostatistics     2200 Cph. N   
 (*) \(*) -- University of Copenhagen   Denmark      Ph: (+45) 35327918
~~~~~~~~~~ - (p.dalgaard at biostat.ku.dk)             FAX: (+45) 35327907

On 18 Nov 2003 10:29:50 -0500, "Arend P. van der Veen"
<apv at capital.net> wrote :
>Hi,
>
>I have what should be a simple question.  I would like to generate a
>histogram of
>
>x <-
c("a","b","c","b","c","c")
>
>where the first bar to be labeled 'c' with height 3, second bar to
be
>labeled 'b' with height 2 and third bar to be labeled 'a'
with height 1.
>
>This should be an easy task in R but I think I am missing something?
Try  barplot(rev(table(x))).

You use table() to calculate frequencies of discrete classes (and
hist() to count frequencies of different bins for continuous
variables), rev() to reverse the order from the natural order, and
barplot() to plot the bars.

Duncan Murdoch