a plugin with statistical plots?

[yitang]

Hey, I wonder if MapThing would be suitable for generating statistical plots like this.

[JamesRamm]

Yes the plotly library is available through the MapThing API itself, currently only in MTContainer.modalChart.

You can of course just require(plotly) yourself and create the necessary elements, perhaps in a modal dialog etc...

[JamesRamm]

Documentation is limited at the moment: https://github.com/JamesRamm/MapThing/blob/master/docs/api/dom.md#containermodalchartdata

and you should consider the API a rough 'beta', but basically it uses the Plotly.newPlot function and passes the data.chartData and data.chartLayout properties to it:

https://plot.ly/javascript/plotlyjs-function-reference/

More work on exposing more of plotly to different parts of MapThing is welcome!

[JamesRamm]

@yitang Do you imagine such plots to be 'stand alone' - i.e. nothing to do with the map itself or that a plot is created by some action on the map? (e.g. someone clicks on a marker and a chart is popped up, something like this)

[yitang]

@JamesRamm i think it would be quite useful to have re-active plots which summarise the statistics of the current viewing region on the map (or the selected region).

[JamesRamm]

Hmmm what kind of statistics? I'm thinking of providing some kind of functionality to open a plot in a different window and leaving it up to the plugin developer to link it to the map. Perhaps making it easier to add a callback function for when the map is moved. Something like

 let mctrl = getMapCtrl()
 mctrl.on('moveend', myCallback)

 function myCallback(){
      //Do work to update plot here 
 }

And some kind of API to create a plot which has references to the map or certain map layers? This would be a bit more expanded than the current plotting api

[yitang]

For example, a histogram of the flood depth?

On 29 Sep 2016, at 16:52, James Ramm notifications@github.com wrote:

Hmmm what kind of statistics? I'm thinking of providing some kind of functionality to open a plot in a different window and leaving it up to the plugin developer to link it to the map. Perhaps making it easier to add a callback function for when the map is moved. Something like

let mctrl = getMapCtrl() mctrl.on('moveend', myCallback)

function myCallback(){ //Do work to update plot here } And some kind of API to create a plot which has references to the map or certain map layers? This would be a bit more expanded than the current plotting api

— You are receiving this because you were mentioned. Reply to this email directly, view it on GitHub, or mute the thread.

[JamesRamm]

Ok, so as mapPig is a generic tool for mapping/visualisation, it doesnt know anything about flood maps etc. However, you can use it for this, but most of the development would be done by you (the plugin developer) in writing a plugin to load flood data and compute statistics on it.

I think, the best way to go about this would be:

• Serve your flood data using something like geoserver or mapserver. This will enable MapPIG to show the flood data (with no development needed in either a plugin or MapPIG)
• Create a WPS service which will calculate the histogram of the flood data for a given bounding box. You can do this with e.g. geoserver or there are python libraries etc
• Create a MapPIG plugin. The plugin will connect to the WPS and give it the bounding box of the map (let mc = getMapCtrl; let pos = mc.getPosition() will return an object, pos where pos.bbox is the bounding box of the map) in order to get the histogram and display that in a chart.

I think that the mapPIG development I suggested earlier - namely, a plotting API which allows you to create separate windows for the plot - is all that is required in mapPIG to allow this. You would use the mctrl.on function to add a callback to update the plot when the map moves.

From a user perspective, I imagine the plugin would simply add a panel which would allow the user to

• select the layer they want to use for histograms (this assumes they have added the flood layer to the map using mapPIGs' built in WMS client)
  • a button to show the plot