Ripley's K function is a statistic for detecting deviations from spatial homogeneity.
Questions tagged [ripley-k]
12 questions
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Edge correction of Ripley's K-function for two 1D point processes?
I am just beginng an investigation involving characterizing the dependence between two 1D stochastic point processes $x$, $y$. The natural approach seems to involve Ripley's K-function:
$$
K(t) = \frac{T}{n_xn_y} \sum_{i=1}^{n_x} \sum_{j=1}^{n_y}…
Aengus
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Ripley's K Function and L Function for Point Patterns
The following is a spatial point pattern:
and these are the corresponding Ripley's K function and L function for this data:
How are these functions interpreted?
hearse
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4
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Ripley K function value in a specific radius and dataset using R's Kest function
I'm having general trouble with calculating Ripley's K function values.
The following is a simple spatial point pattern, where both X and Y range from 0 to 200:
Here's its corresponding Ripley K chart in R:
The problem is, I'm completely failing…
Delano762
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Averaging Ripley's K or L function for several samples
Would much appreciate to hear your opinion about the following strategy:
I have several samples of point patterns, witch are results from somw replicated experiment. The number of points and area of observation vary from experiment to experiment. I…
Sp_J
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What is the best test to check if pattern is uniformed?
Out of the following, which tests are best to use on uniformed data to make sure it is indeed dispersed
$\chi^2$
Simple NNA
High/Low clustering (Getis - ord)
KNN (Ripley)
Moran
Monte Carlo
Randel Marsh
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Is there a name for this in statisitics?
Edit: Ignore this Most of this doesn't make sense and is beyond edits but its too late to delete. If I make too many edits I could be kicked out of this sub like I was in math stack exchange.
I don't have a statistical background but I believe my…
Arbuja
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What is the "sensible default" for the Kest function of the spatstat package?
I'm reading the documentation on the Kest function (page 731) from the spatstat package.
For the argument $r$, that is the "Vector of values for the argument $r$ at which $K(r)$ should be evaluated", it states that:
Users are advised not to specify…
Gabriel
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How to interpret lines crossing on Ripley's K plot
The image above (which I took from another post) illustrates one of the typical patterns in a K plot. It shows a Ripley's K plot showing the actual below the expected up until a radius of about .17, then alongside, finally dipping back below at…
spatialRob
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Residuals plot from ripley K function on spatstat
I am a rookie on R and on spatstat package. I would like some help with the Kres function on spatstat. As is always wise to plot the residuals from any kind of analysis, I'm having trouble interpreting the residuals plot.
My goal in using this…
Renzo Ferreira
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Uniform distribution versus a Poisson homogeneous process with Ripley's K
I'm testing astropy's RipleysKEstimator. I create a 2-dimensional uniform distribution in [0, 1), and obtain its K value for a radius $r=0.5$.
It was my understanding that this should be equivalent to evaluating the Ripley K function on a…
Gabriel
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Interpretation of cross K function (cross type ripley's k function) for spatial point pattern (package spatstat in R)
The main question of my study now is to know whether two rodent species were spatially segregated, aggregated, or just randomized distributed.
I've read the textbook (Spatial Point Patterns: Methodology and Applications with R by Baddeley et al.)…
MittyAdai
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Is the risk a probability?
The Ktest function in the dbmss package returns:
the risk to reject CSR erroneously, based on the distribution of the K function
Below that (as far as I understand) it states that this risk is a p-value.
How is "risk" to be interpreted? Can I…
Gabriel
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