check input coordinate reference systems, clarify output units in descriptions, and make all entry/exit calculations ellipsoidal

[kufreu]

• Addresses issue Check input CRSs #35 by adding checks to see if inputs are in the same projected coordinate coordinate system and are not geographic
• Fixes issue OD Matrix miscalculates time cost if network CRS does not use linear units of meters #36 by making all entry method calculations ellipsoidal and removing the parameter to change the method
• Further clarifies units of inputs and outputs as was requested in issue Clarify time unit #17

[root676]

@kufreu @josephholler thank you for the PRs concerning those issues! I just wanted to ask you to open one PR for each unique issue. This way it is way easier for me to review the associated commits and ensure it is all in the right place. For now just leave the PRs as they are and tell me when they are ready to be reviewed.

[josephholler]

I wondered about that: self-admittedly this is the first time I've tried submitting major changes to another person's GitHub repository. I have to move on to other projects as the summer winds down, though. The pull requests are pretty well organized by different commits: if there are a few changes you don't want, perhaps we could revert those individual commits before you merge?

[root676]

Don't worry - the PR is fine as it is. I am very happy to see contributions from other people here. I'll review the commits ASAP so that we can merge the changes.

[josephholler]

Thanks! One of the things you did not want to change (output field names) should be in dc51e6a , and maybe another in 1efb830

[Sohaahm]

I'm trying to use QNEAT3 in QGIS for computing shortest path for my network, but the result is not accurate .I checked the graph and everything is fine but the problem is it didn't detect disconnected nodes! And it show a distance result for them(I need to find out which nodes were isolated) . does anyone have any idea?

network after EQ.xlsx
nodes.xlsx

My data : 1- line which represent my street after earthquake which caused blocking some segment of the street
2- points : represent street junction and buildings
I want to have a OD matrix (based on shortest path) for every pairs of nodes.

(I checked the result with QGIS network tool and the results does not compatible to each other)

[josephholler]

@Sohaahm, it's better to ask a question like this as a new issue, or to look for the most related issue to reply to. This thread is for a pull request to modify the code base.
Based on you description of the problem, I wonder if you can look more closely at the entry and exit costs. OD Matrix will "snap" all of the origins and destinations to the nearest node of the network and calculate straight-line distance entry & exit costs for the distance between the origin/destination point and the nearest network node. In my experience, those calculations may be inaccurate if you're not using the same projected coordinate systems with linear units of meters for both inputs.

[Skerre]

@kufreu Thanks for this commit, especially regarding the units of outputs. I was always wondering what they were