redwood

redwood3

Locations of 62 seedlings and saplings 
 of California redwood trees.
 
 The data represent the locations of 62 seedlings and saplings 
 of California redwood trees in a square sampling region. 
 They originate from Strauss (1975);
 the present data are a subset extracted by Ripley (1977) 
 in a subregion that has been rescaled to a unit square. Two versions of this dataset are provided: <code>redwood</code>
 and <code>redwood3</code>. The dataset <code>redwood</code> was obtained from the spatial package. 
 In this version the coordinates are given to 2 decimal places
 (multiples of 0.01 units) except for one point which has an $x$ coordinate
 of 0.999, presumably to ensure that it is properly inside the window. The dataset <code>redwood3</code> was obtained from Peter Diggle's webpage.
 In this version the coordinates are given to 3 decimal places
 (multiples of 0.001 units). The ordering of the points is not the same
 in the two datasets.
 
 There are many further analyses of this dataset. It is often used as a 
 canonical example of a clustered point pattern
 (see e.g. Diggle, 1983). The original, full redwood dataset is supplied in the <code>spatstat</code>
 library as <code>redwoodfull</code>.

datasets

spatial

Comprehensive open-source toolbox for analysing Spatial Point Patterns. Focused mainly on two-dimensional point patterns, including multitype/marked points, in any spatial region. Also supports three-dimensional point patterns, space-time point patterns in any number of dimensions, point patterns on a linear network, and patterns of other geometrical objects. Supports spatial covariate data such as pixel images.
Contains over 2000 functions for plotting spatial data, exploratory data analysis, model-fitting, simulation, spatial sampling, model diagnostics, and formal inference.
Data types include point patterns, line segment patterns, spatial windows, pixel images, tessellations, and linear networks.
Exploratory methods include quadrat counts, K-functions and their simulation envelopes, nearest neighbour distance and empty space statistics, Fry plots, pair correlation function, kernel smoothed intensity, relative risk estimation with cross-validated bandwidth selection, mark correlation functions, segregation indices, mark dependence diagnostics, and kernel estimates of covariate effects. Formal hypothesis tests of random pattern (chi-squared, Kolmogorov-Smirnov, Diggle-Cressie-Loosmore-Ford, Dao-Genton) and tests for covariate effects (Cox-Berman-Waller-Lawson, Kolmogorov-Smirnov) are also supported.
Parametric models can be fitted to point pattern data using the functions ppm(), kppm(), slrm(), dppm() similar to glm(). Types of models include Poisson, Gibbs and Cox point processes, Neyman-Scott cluster processes, and determinantal point processes. Models may involve dependence on covariates, inter-point interaction, cluster formation and dependence on marks. Models are fitted by maximum likelihood, logistic regression, minimum contrast, and composite likelihood methods.
A model can be fitted to a list of point patterns (replicated point pattern data) using the function mppm(). The model can include random effects and fixed effects depending on the experimental design, in addition to all the features listed above.
Fitted point process models can be simulated, automatically. Formal hypothesis tests of a fitted model are supported (likelihood ratio test, analysis of deviance, Monte Carlo tests) along with basic tools for model selection (stepwise(), AIC()). Tools for validating the fitted model include simulation envelopes, residuals, residual plots and Q-Q plots, leverage and influence diagnostics, partial residuals, and added variable plots.

Adrian Baddeley

spatstat

Spatial Point Pattern Analysis, Model-Fitting, Simulation, Tests

redwood function

An object of class <code>"ppp"</code>
 representing the point pattern of tree locations.
 The window has been rescaled to the unit square. See <code><a rd-options="" href="/link/ppp.object?package=spatstat&version=1.48-0" data-mini-rdoc="spatstat::ppp.object">ppp.object</a></code> for details of the format of a
 point pattern object.

Format

Original data of Strauss (1975), subset extracted by Ripley (1977).
 Data obtained from Ripley's package spatial
 and from Peter Diggle's website.

Source

Locations of 62 seedlings and saplings 
 of California redwood trees.
 
 The data represent the locations of 62 seedlings and saplings 
 of California redwood trees in a square sampling region. 
 They originate from Strauss (1975);
 the present data are a subset extracted by Ripley (1977) 
 in a subregion that has been rescaled to a unit square.

 Two versions of this dataset are provided: <code>redwood</code>
 and <code>redwood3</code>.

 The dataset <code>redwood</code> was obtained from the spatial package. 
 In this version the coordinates are given to 2 decimal places
 (multiples of 0.01 units) except for one point which has an $x$ coordinate
 of 0.999, presumably to ensure that it is properly inside the window.

 The dataset <code>redwood3</code> was obtained from Peter Diggle's webpage.
 In this version the coordinates are given to 3 decimal places
 (multiples of 0.001 units). The ordering of the points is not the same
 in the two datasets.
 
 There are many further analyses of this dataset. It is often used as a 
 canonical example of a clustered point pattern
 (see e.g. Diggle, 1983).

 The original, full redwood dataset is supplied in the <code>spatstat</code>
 library as <code>redwoodfull</code>.

Original data of Strauss (1975), subset extracted by Ripley (1977).
 Data obtained from Ripley's package spatial
 and from Peter Diggle's website.

redwood: California Redwoods Point Pattern (Ripley's Subset)

Description

Usage

Arguments

Format

Source

References

See Also