ERDDAP™ related R packages - an update

ERDDAP=E2=84=A2 is a web data service that is deployed at locations through=
out the world,  providing easy access to petabytes of  mostly satellite dat=
a,  ocean observations,  fisheries data, and atmospheric data.  There are n=
ow four packages on CRAN  for accessing and using data from ERDDAP=E2=84=A2=
 servers and this is just to cover some recent changes in the packages.

=E2=80=98rerddap=E2=80=99 - this is the main package for accessing data fro=
m ERDDAP=E2=84=A2 servers.  Among the changes in the last six months or so:

   - both =E2=80=98griddap()=E2=80=99 and =E2=80=98tabledap()=E2=80=99 now =
have the option to return data in parquet files.
   - A new function which estimates the size of a =E2=80=98griddap()=E2=80=
=99 download without having to make the request.
   - Improvements to the vignette,  including a table of contents.
   - Interactive map example added to vignette  (see plotdap)

=E2=80=98plotdap=E2=80=99 - makes for easy mapping of =E2=80=98rerddap=E2=
=80=99 extracts
  =

    -  Contour plots using the R package =E2=80=98isoband=E2=80=99
    -  Improved version of =E2=80=98bbox_set=E2=80=99 to create interactive=
 plots using =E2=80=98plotly:ggplotly()=E2=80=99

=E2=80=98rerddapXtracto=E2=80=99 - uses =E2=80=98rerddap::griddap()=E2=80=
=99 to make extracts along tracks and within polygons (though time)

    - refactoring of =E2=80=98rxtracto()=E2=80=99 for speed improvements

=E2=80=98rerddapUtils=E2=80=99 - A new package with an olio of utilities to=
 be used with  =E2=80=98rerddap=E2=80=99

    - a function that restricts the download to a specified season in each =
year
    - a function that splits very large and out-of-memory requests.
    - functions that estimate the size of a =E2=80=98griddap()=E2=80=99 dow=
nload as well as that of a  split request  without having to make the reque=
st.
    - functions to deal with requests and responses for datasets on project=
ed coordinates systems

-Roy