[R-sig-Geo] Leaflet map nested in RShiny App - Improving speed & portability

[Michael Treglia]

I'll just second Barry's idea in particular, to set up as a standalone
webpage. You could even use QGIS and the QGIS2Web Plugin to create that,
and host via GitHub pages or similar.

>From R, after creating a map via leaflet and similar packages, you can use
htmlwidgets::saveWidget() to export as a standalone .html file if I recall
correctly.

The one thing regarding a standalone webpage is that if you have a lot of
objects (especially complex ones), that can be a lot for a browser to
handle (given the data are part of the html file).  Might be worth some
quick experimentation, and simplifying polygons would help. (You could
always create a quick landing page, even generated via rMarkdown, and
having a link for maps by different regions or countries - then you could
have a folder of .html files you could distribute, and users could just
open the landing page, and navigate from there).

Just some quick thoughts... Hope this helps.
Mike T

On Wed, Sep 5, 2018 at 1:17 PM Erin Stearns <estearns88 using gmail.com> wrote:

> Hello all,
>
> Thank you all very much for the great insight!
>
> *McCrea *- thank you very much, I will test using a geojson first, then
> test after reducing geometry.
>
> *Tim* - thank you for the great breakdown and recommended priority list.
> Ideally, I would like to be able to share the interactive map with
> teammates as a file or something akin to it such that they can simply open
> it and interact with the map. RInno is a great option, however I run a
> linux machine, so will look into further, but may need to find another
> option.
>
> *Roman* - the app is currently deployed to shinyapps.io. Thank you for
> sharing about ShinyProxy -- so would this method require 1. Internet and 2.
> local installation (vs internal server)?
>
> *Barry* - wow, thank you for your response! Sounds like this would be the
> best way to solve both issues. I am not as fluent with HTML and JS, but as
> you say, there are likely great guides available to take this route.
>
> Thank you all again, this has been hugely helpful. I wish you all the best
> and hope I can be of help to you at some point!
>
> Best,
> Erin
>
>
> On Wed, Sep 5, 2018 at 12:48 AM Barry Rowlingson <
> b.rowlingson using lancaster.ac.uk> wrote:
>
> >
> >
> > On Wed, Sep 5, 2018 at 12:56 AM, Erin Stearns <estearns88 using gmail.com>
> > wrote:
> >
> >> Hello all!
> >>
> >> I hope this message finds you all well!
> >>
> >> I have 2 questions pertaining to the creation of interactive maps via
> >> Leaflet nested inside an RShiny app. One question has to do with
> >> computation while the other has to do with sharing/off-line
> interactivity.
> >>
> >> *Computation question*
> >> As you see, the RShiny app takes quite a bit of time to render. Does
> >> anyone
> >> have any suggestions for improving this? As previously said, this
> version
> >> only contains 5 countries, thus I cannot continue with my current method
> >> to
> >> reach a global map. I have considered finding centroids of all Admin 2
> >> polygons and retaining attribute information here, then rasterizing the
> >> malaria risk shapefile for visualization and using the 2 instead of a
> >> single shapefile with polygon boundaries and attributes.
> >>
> >>
> > Unless you plan to add any computational functions to this map then I'd
> > strongly recommend creating it as a standalone web app and not a shiny
> app.
> > This will enable you to use lots of useful Leaflet plugins for speeding
> > things up, such as only showing country outlines at low zoom levels, and
> > showing subdivisions only at high zoom levels. This *might* be possible
> > with R's various leaflet packages but I'd go for full javascript control.
> >
> > A standalone map would take its data from a JSON file or similar, and you
> > would then be writing R code that generated that. The mapping app itself
> is
> > written in HTML and JS with CSS styling. There are plenty of guides to
> > web-based interactive mapping, starting with Leaflet.
> >
> >
> >> *Sharing the app/offline interactivity*
> >> I am planning to share this with people who likely do not have R
> installed
> >> on their laptops nor have they ever coded. Does anyone have any
> >> suggestions
> >> for the best way to do this while retaining interactivity?
> >>
> >>  Here's the big win of creating a standalone web map. You only have to
> > distribute the HTML/CSS/JS and they can be viewed directly (or you also
> > supply a tiny server that runs locally and only has to feed the files on
> a
> > localhost port). No need to have a shiny server anywhere, or install R.
> Its
> > simple and clean. It also needs no network connectivity, but you'll not
> get
> > a base map - but you could include a low or medium resolution basemap
> > raster in your package.
> >
> > The only reason to need Shiny here would be if you wanted people to do
> > something computational, like click on a bunch of polygons and then fit a
> > linear model to the selection, since that would require a round-trip to
> the
> > server for R to compute the fit. (although I suspect there's a JS package
> > for linear modelling.... you can do ML in JS these days...)
> >
> >
> >
> >> Thank you all, any insight is greatly appreciated.
> >>
> >> Best,
> >> Erin
> >>
> >>         [[alternative HTML version deleted]]
> >>
> >> _______________________________________________
> >> R-sig-Geo mailing list
> >> R-sig-Geo using r-project.org
> >> https://stat.ethz.ch/mailman/listinfo/r-sig-geo
> >>
> >
> >
>
>         [[alternative HTML version deleted]]
>
> _______________________________________________
> R-sig-Geo mailing list
> R-sig-Geo using r-project.org
> https://stat.ethz.ch/mailman/listinfo/r-sig-geo
>

	[[alternative HTML version deleted]]