# st: RE: re: Possible to have different colours for by() groups in histogram?

 From "Nick Cox" To Subject st: RE: re: Possible to have different colours for by() groups in histogram? Date Wed, 4 Nov 2009 12:48:51 -0000

```Thanks for this. The trick Martin used in his replies to your original
of putting frequently used options in a local macro deserves emphasis.
With not 2 but 3, 4, ... groups it becomes especially valuable.

local opts discrete freq gap(5) xla(1/5)

twoway histogram ease if group==1, color(red) `opts'
|| histogram ease if group==2, color(blue) `opts' by(group, legend(off))

Nick
n.j.cox@durham.ac.uk

Philip Jones

Many thanks for the help Nick! That works perfectly.

only need to include by(group) once in the command (with or without
turning off the legend). Just a small point I found out running the
command both ways.

n.j.cox@durham.ac.uk

>> . twoway histogram ease if group==1, color(red) gap(5) discrete freq
>> by(group) ///
>> || histogram ease if group == 2, color(blue) by(group, legend(off))
>> discrete freq xla(1/5)  gap(5)

Philip Jones

> I would like to know if it is possible in Stata to have different
> colours for plots in histograms created using the by() option. For
> instance, if I would like to plot frequencies of a Likert scale about
> the ease of a process (from 1 to 5) in two separate groups, I can
> generate a nice histogram using the by() option, but both "sides" (or
> plots) of the graph are the same colour.
>
> For instance,
>
> input group ease
> 1 1
> 1 2
> 1 3
> 1 3
> 1 3
> 1 3
> 1 4
> 1 5
> 1 5
> 2 2
> 2 2
> 2 2
> 2 3
> 2 3
> 2 4
> 2 4
> 2 5
> 2 5
> end
> graph twoway histogram ease, by(group) discrete frequency xtick(1(1)5)
> xlabel(1(1)5) gap(5) color(red)
>
> This gives me a histogram, but I would like a different colour for
> each
> plot - say red for the plot on the left and blue for the one on the
> right.
>
> I am sure there is a trivial way of achieving this, but I haven't been
> able to find it. The barlook_options are not valid for histograms, and
> using the graph editor to alter the colour also results in both plots
> becoming the same colour.

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