Add support for Leaflet Marker and Polyline

[syssi]

I'm trying to draw a GPS track. Connected markers by a polyline instead of circles would be awesome.

Kind regards,

Sebastian

[daniellee]

What's a GPS track? Could you explain a little more?

[syssi]

I'm talking about a path of coordinates recorded by a GPS receiver. For example something like this: http://stackoverflow.com/questions/33468905/draw-lines-between-markers-in-leaflet

[hl68fx]

This would be an awesome feature! :) I forgot to mention that support for longitude and latitude coordinates would be great in combination with leaflet marker and polyline.

[daniellee]

Could you give an example of how you would use this? How would you map it to time series data? I'm not sure I follow how connected markers would map to a graphite/Influx query.

@hl68fx What do you mean by support for longitude and latitude coordinates? Having a data point per coordinate pair would explode most time series dbs. Even Elasticsearch has to geohash coordinates to create aggregations as high precision geohash cell queries can have a very negative effect on performance.

[hl68fx]

I would like to have a column for longitude, a column for latitude and one for time in my database. In Grafana I would like to see a map like Google Maps where I can zoom in. In the right corner I would like to be able to choose a time range. Then Grafana shows me a map where I can see how my Arduino with GPS and GSM modem has moved for example the last 6 hours. Just like the timeline in Google Maps where I can see where I moved at which time: https://cnet3.cbsistatic.com/img/mhl3KrwEsp-POBJrHSGkZw1iH1Q=/2015/07/30/80ed1d14-9ae3-4ad2-ab8a-93f5077ed6ef/googlemapstimeline.jpg This could be really useful for fleet management, tracking your own car, dog, cat, bicycle, parcels,...

[samhatchett]

this sounds like a reasonable and useful thing to do. generalizing, we're talking about spatially plotting the movement of a set of unique "things", where a thing's location is a time-variant property ... rather than the "metric" property being spatially fixed and temporally aggregated. In InfluxDB parlance, the geohash would need to be a 'field', rather than a 'tag'. There's probably better language to use that's Grafana-specific so forgive my poor vocabulary.

this is very similar to plotting a f(t) series on a graph, in that successive location-values are joined by a line, but instead of showing a one-dimensional value versus time, we would be showing a two-dimensional location with time range as a parameter.

[daniellee]

Thank you for all the examples! This is a case where I would accept a PR for this but it is not on the roadmap for the next couple of months.

[tkurki]

I would be happy enough with just having circles on the map that make up the track. That way coloring the circles to reflect some measurement is much easier.

I have yet to store any reasonable amounts of geohashes in InfluxDb, but querywise things look pretty good:

>   select first(navigationPosition) as pos, mean(navigationSpeedThroughWater) as stw from signalk WHERE time > now() - 1h group by time(1m)
name: signalk
-------------
time            pos     stw     
1479640860000000000 ud9tk255vhjj    2.625805687203794
1479640920000000000 ud9tk44bx4h4    2.756186440677968

Even Elasticsearch has to geohash coordinates to create aggregations as high precision geohash cell queries can have a very negative effect on performance

We are not talking about querying by position, just retrieving the data by time range so essentially the db is returning strings. I have no exprience how well InfluxDb handles that for large amounts of data. In my case I can limit the sample rate easily to something like a sample a minute or 30 seconds.

Aggregation is a challenge. So far I've thought about justfirst() in InfluxDb, as averaging track coordinates doesn't really work - if you have rounded a mountain / island in an hour is the representative value for that hour in the middle of the mountain / island or just the point where you were in beginning/middle/end of that time period? My hunch is that just picking first() will work ok.

See https://bost.ocks.org/mike/simplify/ for a way to simplify / aggregate a polyline.

[tkurki]

A further functionality would be to be able to click/hover a point in the and have that point in time highllighted in the graph panels on the dashboard.

[tkurki]

FYI I decided to just hack something together from scratch. The code is a mess but it works:

[gesaleh]

Hi can you explain how the data was shown on the map I have a table of alerts that contain the lat and lon I want to display the last alert for each unique device Is this possible?

[tkurki]

See https://github.com/tkurki/grafana-track-map

[bmagistro]

While looking for a solution I stumbled across, https://github.com/pR0Ps/grafana-trackmap-panel and didn't see it referenced here yet. I have not had a chance to look into it yet.