Re: [Gnuplot-info] How to place values on a columnstacked histogram?

[sfeam <sf...@us...>]

On Sunday, 29 October 2017 01:01:10 theozh wrote:
> Thank you again, Ethan, for the explanations and links.
> 
> What's still not clear to me why you can place the
> ysum=0 between two plot commands...

That part is explained by "help plot".
 Syntax:
       plot {<ranges>} <plot-element> {, <plot-element>, <plot-element>}

 Each plot element consists of a definition, a function, or a data source
 together with optional properties or modifiers:
       plot-element:
            {<iteration>}
            <definition> | {sampling-range} <function> | <data source>
            {axes <axes>} {<title-spec>}
            {with <style>}

the "ysum = 0" matches the <definition> template  "foo = <expression>".

> What else can you place in front of a plot command?
> For example:
> n=1
> plot n=n+1 sin(x*n) # works
> plot (n=1,n=n+1) sin(x*n) # doesn't work... why?

because "(n=1,n=n+1)" is not a definition.
You could make it one by adding a dummy assignment:

  plot   dummy=(n=1,n=n+1) sin(x*n)


	Ethan
 
> 
> Anyway, my original question is solved :-).
> Nevertheless, I played around a little further.
> If the portions in the stacked histogram are too small to fit a number,
> the following code shows a way to place those numbers on the side with a
> pointing arrow.
> Maybe some people also mind find this useful.
> 
> The following code was working on my system (Win7, gnuplot 5.2) and
> should be ready for copy&paste&plot. Be aware that the mail program
> might have "messed up" the line breaks.
> 
> ###### start gnuplot code
> reset
> $Data <<EOD
> XXX Header1 Header2
> one 10 50
> two 3 2
> three 30 15
> four 40 5
> five 0.5 0.5
> six 0.6 0.6
> seven 1 17
> EOD
> 
> set style data histogram
> set style histogram columnstacked
> set style fill solid border -1
> set boxwidth 0.6
> 
> YminSpace = 4
> YStep = 2
> YExtraDistance = -YStep
> XShift(n) = (n < YminSpace) ? 0.45 : 0
> YShift(n) = (n < YminSpace) ?
> (YExtraDistance=YExtraDistance+YStep,YExtraDistance) :
> (YExtraDistance=-YStep,0)
> 
> plot \
>   $Data u 2 ti col , '' u 3:key(1) ti col, \
>   ysum=0 '' skip 1 using (0+XShift($2)):((ysum = ysum + $2,
> ysum-$2/2+YShift($2))):2 with labels notitle, \
>   ysum=0 '' skip 1 using (1+XShift($3)):((ysum = ysum + $3,
> ysum-$3/2+YShift($3))):3 with labels notitle,\
>   ysum=0 '' skip 1 using ($2>YminSpace ? 1/0:(0+XShift($2)-0.05)):((ysum
> = ysum + $2, ysum-$2/2+YShift($2))):(-0.1):(-YExtraDistance) ls -1 with
> vectors not,\
>   ysum=0 '' skip 1 using ($3>YminSpace ? 1/0:(1+XShift($3)-0.05)):((ysum
> = ysum + $3, ysum-$3/2+YShift($3))):(-0.1):(-YExtraDistance) ls -1 with
> vectors not,\
> 
> ###### end gnuplot code