integral.linim: Integral on a Linear Network

In spatstat.linnet: Linear Networks Functionality of the 'spatstat' Family

Integral on a Linear Network

Description

Computes the integral (total value) of a function or pixel image over a linear network.

Usage

## S3 method for class 'linim'
integral(f, domain=NULL, weight=NULL, ...)

## S3 method for class 'linfun'
integral(f, domain=NULL, weight=NULL, ..., exact=FALSE, delta, nd)

Arguments

f	A pixel image on a linear network (class "linim") or a function on a linear network (class "linfun").
domain	Optional window specifying the domain of integration. Alternatively a tessellation (class "tess" or "lintess").
weight	Optional numerical weight function for the integration. A pixel image (object of class "linim" or "im"), a function (object of class "linfun", "funxy" or a a function(x,y)) or anything acceptable to as.linim.
...	Ignored.
exact	Logical value specifying whether to use a more accurate (and slower) calculation method. See Details.
delta	Optional. The step length (in coordinate units) for computing the approximate integral (if exact=FALSE). A single positive number.
nd	Optional. Integer giving the approximate number of sample points on the network (if exact=FALSE).

Details

The integral (total value of the function over the network) is calculated.

If domain is a window (class "owin") then the integration will be restricted to this window. If domain is a tessellation (class "tess" or "lintess") then the integral of f in each tile of domain will be computed.

If weight is given, effectively the integral of weight * f is computed.

For objects of class "linfun" there is the option of using a more accurate calculation method in which the integral along each segment of the network is computed separately using the utility integrate from the stats package. If exact=TRUE, additional arguments ... are passed to integrate to control the computation.

Value

A single numeric or complex value (or a vector of such values if domain is a tessellation).

Author(s)

\spatstatAuthors

.

See Also

linim, integral.im, integrate

Examples

  # make a function and image data
  xcoord <- linfun(function(x,y,seg,tp) { x }, simplenet)
  integral(xcoord)
  integral(xcoord, exact=TRUE)
  X <- as.linim(xcoord)
  integral(X)

  # integrals inside each tile of a tessellation
  A <- quadrats(Frame(simplenet), 3)
  integral(X, A)

spatstat.linnet documentation built on Jan. 31, 2026, 5:06 p.m.