1. Exquisite Tweets from @underdarkGIS, @hruske, @pwramsey, @bitnerd

    billdollinsCollected by billdollins

    underdarkGIS

    Anita Graser

  2. @underdarkGIS This is doable by using daterange or tstzrange types for temporal and postgis for spatial aspects. postgresql.org/docs/current/s…

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    hruske

    Zejn

  3. @hruske Do you know any examples where this is used to model moving objects e.g. cars or animals? #gistribe

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    underdarkGIS

    Anita Graser

  4. @underdarkGIS No, not really. I can come up with an example, if it helps.

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    hruske

    Zejn

  5. @hruske If it's not too much trouble, that would be great! Essentially, I envision a moving point (trajectory) datatype

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    underdarkGIS

    Anita Graser

  6. @pwramsey @hruske e.g. which truck passed checkpoint A during a given hour, should interpolate positions between observations

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    underdarkGIS

    Anita Graser

    @pwramsey @hruske or when and where were truck A and B at the same location

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    underdarkGIS

    Anita Graser

  7. @pwramsey @underdarkGIS @hruske between the temporal and linear referencing in postgis, all the functionality is there

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    bitnerd

    David Bitner

  8. .@bitnerd @pwramsey @hruske lot of queries working already, thanks to your recommendations. Any tips for computing speeds along LinestringM?

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    underdarkGIS

    Anita Graser

  9. @underdarkGIS You could do a sum(ST_Length(geom, true)) / (upper(timeslice) - lower(timeslice)) calc to get avg. speed @bitnerd @pwramsey

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    hruske

    Zejn

  10. @hruske @bitnerd @pwramsey thank you! Was thinking of speed between consecutive points rather than just average over whole trajectory

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    underdarkGIS

    Anita Graser

  11. @underdarkGIS Yeah, you don't need to sum it, you can do this per row, at least as per my example, and get segment speed. @bitnerd @pwramsey

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    hruske

    Zejn

  12. @hruske @bitnerd @pwramsey any recomm. to get location along LinestringM trajectories at a certain time each day, e.g. any day at midnight?

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    underdarkGIS

    Anita Graser

  13. @pwramsey @hruske @bitnerd I can query one certain day at midnight but not all possible midnights that way, as far as I can tell ...

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    underdarkGIS

    Anita Graser

  14. @underdarkGIS @pwramsey @hruske ooooh, totally doable. My kind of puzzle, will play tmrw when at computer

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    bitnerd

    David Bitner

  15. @bitnerd @pwramsey @hruske great, thank you! I'll also give this puzzle a go some more

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    underdarkGIS

    Anita Graser

    @bitnerd @pwramsey @hruske your optimism was a great motivation, here's my first take, if trajectories don't cross day borders pic.twitter.com/V84s0qGoSf

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    underdarkGIS

    Anita Graser

    underdarkGIS

    Anita Graser