Re: [Gretl-users] Plot multiple kernel densities in the same graph
On Sun, 7 Apr 2013, Riccardo (Jack) Lucchetti wrote:
On Sat, 6 Apr 2013, Giuseppe Vittucci wrote:
> Dear all,
>
> I would like to plot the kernel density estimates of a particular
> variable across two different years in the same graph.
>
> Is there a way to do it in gretl?
One of the possible solutions is to use the kdensity() function con construct
a matrix which is then handed to gnuplot.
Actually, it may be convenient to slightly generalise this and wrap it
into a function. See below:
<hansl>
set echo off
set messages off
function void double_density(series x, series d)
string s = argname(d)
matrix d0 = kdensity(d ? NA : x)
matrix d1 = kdensity(d ? x : NA)
matrix dd = (d0 ~ NA) | (d1[,1] ~ NA ~ d1[,2])
sprintf cn "x %s=0 %s=1", s, s
colnames(dd, cn)
gnuplot 2 3 1 --matrix=dd --with-lines --output=display
end function
open australia.gdt
dum = t<1980:1
double_density(IAU, dum)
open mroz87.gdt
double_density(WA, LFP)
</hansl>
-------------------------------------------------------
Riccardo (Jack) Lucchetti
Dipartimento di Scienze Economiche e Sociali (DiSES)
Università Politecnica delle Marche
(formerly known as Università di Ancona)
r.lucchetti(a)univpm.it
http://www2.econ.univpm.it/servizi/hpp/lucchetti
-------------------------------------------------------