[R] ggmap Question

[Josh B]

Hello r-help,

My question is regarding specific coding in ggmap.

I am mapping radio telemetry detections of shorebirds using ggmap. I want
the map to depict a specific point (lat/lon of a telemetry tower) where the
bird was detected, as well as the following variables associated with that
lat/long: date of detection and the number of individuals detected on that
date.

To avoid masking detections, I would like to include a graduated point that
will change size based upon the number of individuals detected. The goal is
to show what date a bird was detected at a telemetry tower and how many
birds were detected at that telemetry, using a color scale and graduated
symbol.

My thought is to have the graduated color symbol stack on itself, larger
symbol on the bottom and the smallest on the top (or make them transparent
enough so symbols underneath others can be seen) . This way the number of
individuals detected at the telemetry towers and the date they were
detected are represented by one image. See link for example image
<https://i.stack.imgur.com/fROg6.png>.


Sample Data:

X motusTagID         ts recvLat recvLon recvProjID recvSiteName
speciesSci num.det num.id
1 1      24741 2018-01-01    51.3   -80.6          1     Moosonee Calidris
canutus       4      1
2 2      24743 2018-01-04    51.3   -80.6          1     Moosonee Calidris
canutus       4      1
3 3      24747 2018-01-04    51.3   -80.6          1     Moosonee Calidris
canutus       4      1
4 4      25089 2018-01-04    51.3   -80.6          1     Moosonee Calidris
canutus       8      1
5 5      24779 2018-01-25    51.3   -80.6          1     Moosonee Calidris
canutus       4      1
6 6      24746 2018-01-25    51.3   -80.6          1     Moosonee Calidris
canutus       4      1

Sample Code I have Tried:

See link to another source for a sample of the code I tried.

https://stackoverflow.com/questions/57618926/how-do-i-code-in-r-so-my-time-stamp-field-is-represented-by-a-color-scale-and-th?noredirect=1#comment101931264_57618926


Thank you.


*Joshua N. Barth*

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