R help - Nov 2017 - Extract all point in a quadrats by spatstat package

Hi,

With the following code i can divides window into quadrats and counts the
numbers of points in each quadrat.

library(spatstat)
X <- runifpoint(50)
quadratcount(X)
quadratcount(X, 4, 5)
quadratcount(X, xbreaks=c(0, 0.3, 1), ybreaks=c(0, 0.4, 0.8, 1))
qX <-? quadratcount(X, 4, 5)
plot(X)
plot(qX, add=TRUE)

But I want to mark each? quadrats? and select/ extract only those points by
selecting quadrats id .?
Can anyone plese help me regarding this issue ?
Thanks in advance .



Regards.............
Tanvir Ahamed 
Stockholm, Sweden???? |??mashranga at yahoo.com