Thanks Jeroen, Here is a link to the timezone geopackage.
https://drive.google.com/file/d/1IS_bExc5M2IhadK9hzE012oorvV3IbBp/view?usp=sharing You could also use the shapefile from https://github.com/evansiroky/timezone-boundary-builder/releases/tag/2020d I am using the version with oceans. I suspect that the shapefile may be slightly faster than the gpkg, but I haven't tested it yet. Here is the gpkg of 10,000 random points. https://drive.google.com/file/d/1Vz0ho8nQ9rxG6YUG_JebyVygBkjMFsGr/view?usp=sharing Here is a short script that you can run in the QGIS python console to time how long it takes to search the timezone for each of the 10,000 points. https://drive.google.com/file/d/1VMBs6AdvdvWOI_S9XvEaDm3oVyr_vHNv/view?usp=sharing You will either need to pip install the timezonefinder library or install the datetimetools-3.0.1.zip release which will make the QGIS python console aware of the library. https://github.com/NationalSecurityAgency/qgis-datetimetools-plugin/releases/tag/3.0.1 The mention of ArcGIS is simply that we have an ESRI centric environment and it is difficult to get QGIS accepted so I try to do everything I can to make QGIS look appealing. Thanks once again, Calvin On Tue, Feb 2, 2021 at 5:23 PM Groene Bij <[email protected]> wrote: > Hi Calvin, > > > > Could you somehow send me a copy of the 10.000 random point layer and the > gpkg with the time zones? I would like to try some things, and see if I can > come up with some suggestions. I could send you an upload link where you > can upload those files to me, if needed. > > > > And I am also trying to understand the issue at stake here. You keep > referring to ArcGIS. Does ArcGIS has a similar tool incorporated In its > software, including the data? > > > > And is it necessary to use this tool offline? If so, a database / data > file is needed anyway. Than the question is, should it be part of the tool, > or should you be able to download the data when needed (or better, > beforehand). Benefit of downloading the data separately could be more up to > date time zone information. > > > > Kind regards, > > Jeroen Hovens > > > > > > *Van:* Qgis-user <[email protected]> *Namens *C Hamilton > *Verzonden:* dinsdag 2 februari 2021 19:40 > *Aan:* Nyall Dawson <[email protected]> > *CC:* QGIS Users <[email protected]>; Tim Sutton <[email protected]>; > qgis-developer <[email protected]> > *Onderwerp:* Re: [Qgis-user] [QGIS-Developer] New QGIS Date/Time Tools > Plugin > > > > I created a layer of 10,000 random points. Using timezonefinder to look up > each point took 44 seconds. I tried using *Vector->Geoprocessing > Tools->Intersection...* to find the time zones for each of the points and > it took over 4 minutes. > > > > Is there a better way to locate which polygon a point is in? 4 minutes is > not good. Perhaps the intersection algorithm is not the way to go, but I am > not sure what is. I can't imagine that iterating through each point and > then iterating through each polygon until an intersection match is found is > going to be overlay efficient, but I will try it. Is there a better way? > > > > Thanks, > > > > Calvin > > > > > > > I wonder what the difference in time would be to use a gpkg and QGIS > point in polygon look up vs timezonefinder lookup. Will it be faster or > slower? I'm not sure without testing. What are your thoughts? I would > choose the faster of the two. > > I'd certainly hope a dedicated GIS application can do this faster than > a random Python library :D > > > I just converted the timezone data to a gpkg and its size is 102Mb. The > data size for timezonefinder using the same data set is 49Mb. The > optimization in timezonefinder can produce a maximum error of 1cm at the > equator as they use 32 bit ints for the data. It might actually be better > to use the gpkg file, but it is double in size. I will investigate using > the gpkg data. > > You may want to try a shapefile too, just in case...! > > Nyall > > > > > > It seems to me that if a plugin requires a certain dataset to function > then that data should be included with it and not require an additional > download, but I understand the issues that this could cause so I am not > sure of the best way forward. For our use it is definitely better to > include the data with the plugin. > > > > I guess what I would like you to take from this conversation is that > some users have a completely different environment and face different > challenges then what you do when it comes to dealing with software. I wish > that it was easier for me to get QGIS acceptance in our workforce but > ArcGIS still rules. > > > > Thanks for your ideas and all of the hard work that you do to keep QGIS > moving forward. > > > > I wish you all the very best! > > > > Calvin > > > >> Given that the size of the python library is almost entirely the size > >> of the timezone boundaries themselves, have you considered: > >> - avoiding the library entirely, and insteading using a standard > >> shapefile/gpkg/... of the boundaries and using QGIS vector layer > >> methods to determine the timezone for a point > >> - deferring the download of the boundary spatial data, so that it's > >> not supplied with the plugin but instead the plugin automatically > >> downloads it on first launch? > >> > >> This would avoid the need for the large size plugin, allowing it to be > >> supplied via the standard QGIS repo while still providing its full > >> functionality... > >> > >> Nyall > >> > >> > >
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