ewcdf {spatstat} | R Documentation |
Compute a weighted version of the empirical cumulative distribution function.
ewcdf(x, weights = rep(1/length(x), length(x)))
x |
Numeric vector of observations. |
weights |
Numeric vector of non-negative weights
for x . |
This is a modification of the standard function ecdf
allowing the observations x
to have weights.
The weighted e.c.d.f. (empirical cumulative distribution function)
Fn
is defined so that, for any real number y
, the value of
Fn(y)
is equal to the total weight of all entries of
x
that are less than or equal to y
. That is
Fn(y) = sum(weights[x <= y])
.
Thus Fn
is a step function which jumps at the
values of x
. The height of the jump at a point y
is the total weight of all entries in x
number of tied observations at that value. Missing values are
ignored.
If weights
is omitted, the default is equivalent to
ecdf(x)
.
A function, of class "ecdf"
, inheriting from "stepfun"
.
Adrian Baddeley adrian@maths.uwa.edu.au http://www.maths.uwa.edu.au/~adrian/ and Rolf Turner rolf@math.unb.ca http://www.math.unb.ca/~rolf
x <- rnorm(100) w <- runif(100) plot(ewcdf(x,w))