determine mean value on 0Y histogram axis

I am drawing histograms using hist command as below:

hist(plikTVDI, ylab开发者_运维问答='częstość występowania',
     xlab=xetyk, col='red', main=etykieta, cex.lab=1.5)

Then I am adding tekst:

text(x=mean(plikTVDI,na.rm=TRUE),y=40,labels=tekst_srednia_l, cex=3, col='blue')

Is there any possibility to determine where is mean of y axis (it will be better then constant 40).

I may not be understanding your question correctly, but I think you'd like to identify the midpoint of the y axis when you create a histogram?

If that's the case, if you store the results of hist in a variable, like so:

tmp <- hist(...)

you can access the count values that determine the heights of the bars via tmp$counts. So the midpoint of the y axis would be tmp$counts / 2.

Alternatively, if you wanted the mean of the heights of the bars, you could simply do:

mean(tmp$counts)