HardcorePointProcess
✖
HardcorePointProcess
represents a hard-core point process with constant intensity μ and hard-core radius rh in .
Details


- HardcorePointProcess models point configurations where the points cannot be within a radius rh of each other but otherwise are uniformly distributed with intensity μ points per volume unit.
- The hard-core model is typically used when the underlying points behave like a collection of hard marbles, including things like gas molecules, metal deposits, sintered material and biological cells.
-
- The hard-core point process can be defined as a GibbsPointProcess in terms of its intensity μ and the pair potential
or pair interaction
, which are both parametrized by rh as follows:
-
pair potential pair interaction - A point configuration
from a hard-core point process HardcorePointProcess[μ,rh,d] in an observation region reg has density function
proportional to
with respect to PoissonPointProcess[1,d].
- The Papangelou conditional density
for adding a point
to a point configuration
is
.
- HardcorePointProcess allows μ and rh to be any positive numbers, and d to be any positive integer.
- HardcorePointProcess is a special case of GibbsPointProcess and is equivalent to StraussPointProcess[μ, 0, rh].
- Possible Method settings in RandomPointConfiguration for HardcorePointProcess are:
-
"MCMC" MCMC birth and death "Exact" coupling from the past - Possible PointProcessEstimator settings in EstimatedPointProcess for HardcorePointProcess are:
-
Automatic automatically choose the parameter estimator "MaximumPseudoLikelihood" maximize the pseudo-likelihood - HardcorePointProcess can be used with such functions as RipleyK and RandomPointConfiguration.
Examples
open allclose allBasic Examples (2)Summary of the most common use cases
Sample from a hard-core point process in :

https://wolfram.com/xid/0g38do4fqet8yf872-f9h16b

https://wolfram.com/xid/0g38do4fqet8yf872-cr2aru

https://wolfram.com/xid/0g38do4fqet8yf872-tfb0w

Visualize the points in the sample:

https://wolfram.com/xid/0g38do4fqet8yf872-1pasjf

Sample from a hard-core point process defined on the surface of the Earth:

https://wolfram.com/xid/0g38do4fqet8yf872-dm5er3


https://wolfram.com/xid/0g38do4fqet8yf872-h6txtp


https://wolfram.com/xid/0g38do4fqet8yf872-c96vjb

Scope (3)Survey of the scope of standard use cases
Generate three realizations from a hard-core point process in :

https://wolfram.com/xid/0g38do4fqet8yf872-pjmeyf

https://wolfram.com/xid/0g38do4fqet8yf872-fat85p

https://wolfram.com/xid/0g38do4fqet8yf872-y8f38b


https://wolfram.com/xid/0g38do4fqet8yf872-kv2ge2


https://wolfram.com/xid/0g38do4fqet8yf872-casa32

Generate three realizations from a hard-core point process on the surface of the Earth:

https://wolfram.com/xid/0g38do4fqet8yf872-cw3l9q

https://wolfram.com/xid/0g38do4fqet8yf872-duwsm2

https://wolfram.com/xid/0g38do4fqet8yf872-o1wesh

Visualize the point configurations:

https://wolfram.com/xid/0g38do4fqet8yf872-t6zgr


https://wolfram.com/xid/0g38do4fqet8yf872-b50yar

Generate samples with increasing hard-core radius:

https://wolfram.com/xid/0g38do4fqet8yf872-qpbanu

https://wolfram.com/xid/0g38do4fqet8yf872-qrmox4

https://wolfram.com/xid/0g38do4fqet8yf872-5qi0v

https://wolfram.com/xid/0g38do4fqet8yf872-cuvxs8

Plot samples with the repulsion disks:

https://wolfram.com/xid/0g38do4fqet8yf872-xgebf9

https://wolfram.com/xid/0g38do4fqet8yf872-bq5vc4

Check that the hard-core constraint is obeyed:

https://wolfram.com/xid/0g38do4fqet8yf872-g5f79f

https://wolfram.com/xid/0g38do4fqet8yf872-bih4qk


https://wolfram.com/xid/0g38do4fqet8yf872-n88e8

Options (4)Common values & functionality for each option
Method (4)
Simulate using the Markov chain Monte Carlo method:

https://wolfram.com/xid/0g38do4fqet8yf872-mr431h

https://wolfram.com/xid/0g38do4fqet8yf872-q096j

Specify the number of recursive calls to the sampler:

https://wolfram.com/xid/0g38do4fqet8yf872-b28ma3


https://wolfram.com/xid/0g38do4fqet8yf872-hxjlyn

Provide an initial state for the simulation:

https://wolfram.com/xid/0g38do4fqet8yf872-gx4n0o

https://wolfram.com/xid/0g38do4fqet8yf872-f40juq

The initial point must have nonzero density to ensure that the result is a valid configuration:

https://wolfram.com/xid/0g38do4fqet8yf872-ggxwan

https://wolfram.com/xid/0g38do4fqet8yf872-baijzk


https://wolfram.com/xid/0g38do4fqet8yf872-cdwlwh

Check if the minimal distance between the points is smaller than the hard-core radius:

https://wolfram.com/xid/0g38do4fqet8yf872-vir4r


https://wolfram.com/xid/0g38do4fqet8yf872-fqjy8c

Visualize the birth and death process at different stages:

https://wolfram.com/xid/0g38do4fqet8yf872-iizyek

https://wolfram.com/xid/0g38do4fqet8yf872-o4dprz

https://wolfram.com/xid/0g38do4fqet8yf872-6e66ov

Use coupling from the past for exact sampling:

https://wolfram.com/xid/0g38do4fqet8yf872-o474b1

https://wolfram.com/xid/0g38do4fqet8yf872-ea30a8


https://wolfram.com/xid/0g38do4fqet8yf872-kpeujq

Properties & Relations (3)Properties of the function, and connections to other functions
For the large intensity μ, the samples saturate:

https://wolfram.com/xid/0g38do4fqet8yf872-hux991

https://wolfram.com/xid/0g38do4fqet8yf872-cmj10y

https://wolfram.com/xid/0g38do4fqet8yf872-gzg6od

https://wolfram.com/xid/0g38do4fqet8yf872-yyiq3s

https://wolfram.com/xid/0g38do4fqet8yf872-kdvbpq

The number of points saturates at a density that is significantly lower than the theoretical maximum packing:

https://wolfram.com/xid/0g38do4fqet8yf872-2feui

https://wolfram.com/xid/0g38do4fqet8yf872-gjjp9n

https://wolfram.com/xid/0g38do4fqet8yf872-8xvykp


https://wolfram.com/xid/0g38do4fqet8yf872-cc51n0


https://wolfram.com/xid/0g38do4fqet8yf872-pahnu


https://wolfram.com/xid/0g38do4fqet8yf872-ch273w

https://wolfram.com/xid/0g38do4fqet8yf872-cx0kdm

https://wolfram.com/xid/0g38do4fqet8yf872-dqrgjn


https://wolfram.com/xid/0g38do4fqet8yf872-hla1f


https://wolfram.com/xid/0g38do4fqet8yf872-nop6t

Compute the average number of points in a unit disk for a hard-core point process:

https://wolfram.com/xid/0g38do4fqet8yf872-ppr43z

https://wolfram.com/xid/0g38do4fqet8yf872-mai9ud

Possible Issues (1)Common pitfalls and unexpected behavior
By default, the simulation will run until the number of points converges to a steady state, or until the default number of iterations is reached:

https://wolfram.com/xid/0g38do4fqet8yf872-ja4d7q

https://wolfram.com/xid/0g38do4fqet8yf872-bnb3wu


Raise the number of recursive calls to the sampler:

https://wolfram.com/xid/0g38do4fqet8yf872-m520k


https://wolfram.com/xid/0g38do4fqet8yf872-hcyskp

Wolfram Research (2020), HardcorePointProcess, Wolfram Language function, https://reference.wolfram.com/language/ref/HardcorePointProcess.html.
Text
Wolfram Research (2020), HardcorePointProcess, Wolfram Language function, https://reference.wolfram.com/language/ref/HardcorePointProcess.html.
Wolfram Research (2020), HardcorePointProcess, Wolfram Language function, https://reference.wolfram.com/language/ref/HardcorePointProcess.html.
CMS
Wolfram Language. 2020. "HardcorePointProcess." Wolfram Language & System Documentation Center. Wolfram Research. https://reference.wolfram.com/language/ref/HardcorePointProcess.html.
Wolfram Language. 2020. "HardcorePointProcess." Wolfram Language & System Documentation Center. Wolfram Research. https://reference.wolfram.com/language/ref/HardcorePointProcess.html.
APA
Wolfram Language. (2020). HardcorePointProcess. Wolfram Language & System Documentation Center. Retrieved from https://reference.wolfram.com/language/ref/HardcorePointProcess.html
Wolfram Language. (2020). HardcorePointProcess. Wolfram Language & System Documentation Center. Retrieved from https://reference.wolfram.com/language/ref/HardcorePointProcess.html
BibTeX
@misc{reference.wolfram_2025_hardcorepointprocess, author="Wolfram Research", title="{HardcorePointProcess}", year="2020", howpublished="\url{https://reference.wolfram.com/language/ref/HardcorePointProcess.html}", note=[Accessed: 09-July-2025
]}
BibLaTeX
@online{reference.wolfram_2025_hardcorepointprocess, organization={Wolfram Research}, title={HardcorePointProcess}, year={2020}, url={https://reference.wolfram.com/language/ref/HardcorePointProcess.html}, note=[Accessed: 09-July-2025
]}