polygon graph

Hi all,

I have a matrix dd with dates and data. i WANT to create a grpah with shade
between the line and the zero axis. I?m trying to use polygon but something
doesn? t work

Imagine.

I want to plot

g<-read.table("dd.txt", col.names=c("fecha","DP"))

g$fecha <- as.Date(g$fecha, format="%d/%m/%Y")

t<-g$fecha
st<-length(g$DP)

ft<-plot(t,g$DP,type="l",ylab="DP")

polygon(c(1, 1:st, st), c(0, g$USGDP, 0), col = "blue")

abline(h = 0, lwd = 1, col = "black")

If I ommit ploygon line the doc works properly (it plots a graph line).

But I want to colur the area below or over the line and the zero axis.

Can you guide or indicate because in this case polygon doesn?t work.

I attach the two files.

Thanks in advance for all.


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