[R-sig-Geo] Correlograms of Moran's I with progressive Bonferroni correction

Mingke Li m||@er|n1919 @end|ng |rom gm@||@com
Mon Mar 18 14:59:02 CET 2019


Hi Roger,

According to the book "Numerical Ecology" by Legendre&Legendre in 2012, a
progressive (sequential) Bonferroni correction is a modified version of
Bonferroni correction, where the Bonferroni-corrected level is computed for
each distance class separately instead of using a consistent level for all
distance classes. This is done by using for each distance class the number
of tests actually performed up to that distance class. For example, if we
have 10 distance classes, and we use a=0.05 as a probability level, then
the adjusted a (a') for the first distance class is a'=a/1=0.05, for the
second distance class is a'=a/2=0.025 ... for the 10th distance class is
a'=a/10=0.005.

I've checked the mpmcorrelogram package, it seems that this package is for
creating multivariate correlograms. But what I hope to get is correlograms
of autocorrelation over one variate (e.g. Moran's I).

Hope this is clearer. Thank you for your help.

Mingke

On Mon, Mar 18, 2019 at 5:41 AM Roger Bivand <Roger.Bivand using nhh.no> wrote:

> On Sun, 17 Mar 2019, Mingke Li wrote:
>
> > Dear list,
> >
> > I am trying to generate a correlogram of Moran's I, with symbols showing
> if
> > the coefficient is significant or not after the progressive Bonferroni
> > correction. Now I'm using the "correlog" function in the package ncf to
> > calculate the coefficients among all distance classes. I symbolized the
> > dots in the plot to show if they are significant or not (after
> progressive
> > Bonferroni correction), say, open circles for non-significant
> coefficients,
> > and solid circles for significant coefficients.
>
> Explain what you mean here by progressive Bonferroni correction, please.
> Could you rather see what is done in the mpmcorrelogram package, and
> report back if it makes sense?
>
> Roger
>
> >
> > These are the codes I used in R:
> >
> >> correlog.L2.2014new <- correlog(Grid.2014.all$Lng, Grid.2014.all$Lat,
> > Grid.2014.all$L2_Average,latlon = T, na.rm=T, increment=5, resamp=200)
> >> for (i in list(1:length(correlog.L2.2014new$p))) {
> >  correlog.L2.2014new$adjp[i]=correlog.L2.2014new$p[i]*i
> > }
> >> plot(correlog.L2.2014new$correlation[1:80], type="b", cex=1.5, lwd=1.5,
> > ylim=c(-0.1,0.7),
> >     pch=ifelse(((correlog.L2.2014new$adjp>0.05)),1,16),
> >     xlab="Distance (km)", ylab="Moran's I", cex.lab=2, cex.axis=1.5);
> > abline(h=0)
> >
> > I also found the function "sp.correlogram" in the package spdep to make
> the
> > correlogram with Bonferroni correction.
> >
> > Now I have three questions:
> >
> > 1. Can I set a "up-limit" to the "correlog" function? For example, if I
> > just need the first 80 distance classes to generate the graph (as shown
> in
> > the plot code), is it possible to let the "correlog" function skip the
> rest
> > distance classes to save the computation time?
> >
> > 2. Is my code of generating p values after the progressive Bonferroni
> > correction correct? If not, how should I fix it?
> >
> > 3. Now I'm kind of correcting the p value manually based on my
> > understanding of progressive Bonferroni correction. Is there any function
> > in any R packages for creating correlograms with progressive Bonferroni
> > correction? "sp.correlogram"  has a parameter setting "p.adj.method" but
> it
> > seems do not have a progressive Bonferroni correction option?
> >
> > I just start to work with the correlograms recently; any advice or
> > solutions are welcome. Thank you in advance!
> >
> > Erin
> >
> >       [[alternative HTML version deleted]]
> >
> > _______________________________________________
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> > R-sig-Geo using r-project.org
> > https://stat.ethz.ch/mailman/listinfo/r-sig-geo
> >
>
> --
> Roger Bivand
> Department of Economics, Norwegian School of Economics,
> Helleveien 30, N-5045 Bergen, Norway.
> voice: +47 55 95 93 55; e-mail: Roger.Bivand using nhh.no
> https://orcid.org/0000-0003-2392-6140
> https://scholar.google.no/citations?user=AWeghB0AAAAJ&hl=en
>

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