[R] Help with Radius problem

[Poling, William]

Good morning Jim.

This is awesome start, visualization is splendid, thank you very much.

I have signed on to r-sig-geo and submitted my question there. I have no idea of the volume of traffic on that list
However, hopefully, I will gain additional insight into how to determine max number of member locations in the most minimum radius area.

Have a great day!

WHP



Proprietary

-----Original Message-----
From: Jim Lemon <drjimlemon using gmail.com> 
Sent: Wednesday, May 13, 2020 1:39 AM
To: Poling, William <PolingW using aetna.com>
Cc: r-help using r-project.org
Subject: [EXTERNAL] Re: [R] Help with Radius problem

**** External Email - Use Caution ****

Hi Bill,
A while ago I devised a couple of functions to accumulate millions of geographic locations of events and then display the resulting matrix of values on an existing plot. This may be of use to you, at least in the visualization of the density of the locations. As your example data only included a few points, the resulting plot looks pretty chunky as I had to use a large symbol to make the cells with non-zero counts obvious.

# read in your sample data
source("wp_data.R")
library(plotrix)
geomat<-makeDensityMatrix(geodat[,c("latitude","longitude")],
xlim=range(geodat$longitude),ylim=range(geodat$latitude))
# Range of density (>0) - 1.119816 3.922018
latlim<-range(geodat$latitude)
lonlim<-range(geodat$longitude)
library(maps)
map("world",xlim=lonlim,ylim=latlim)
axis(1)
axis(2)
densityGrid(geomat,range.cex=c(1,5),xlim=lonlim,ylim=latlim,
 red=c(0.5,1),green=0,blue=0,pch=15)

Jim

On Wed, May 13, 2020 at 10:57 AM Poling, William via R-help <r-help using r-project.org> wrote:
>
> #RStudio Version Version 1.2.1335
> sessionInfo()
> # R version 4.0.0 Patched (2020-05-03 r78349)
> #Platform: x86_64-w64-mingw32/x64 (64-bit) #Running under: Windows 10 
> x64 (build 17763)
>
> Hello I am trying to figure out how to create concentration of ID's in 
> the following data, based on determining the highest concentration in 
> the smallest radius area based on Longitude and Latitude (geo 
> location)
>
> I have reviewed many websites looking for a function or tutorial, (if 
> you are aware of either please let me know)
>

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