[GRASS-dev] [GRASS GIS] #3292: Query on spatially overlapped features in one vector map

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1

#3292: Query on spatially overlapped features in one vector map
-------------------------+-------------------------
Reporter: hcho | Owner: grass-dev@…
     Type: enhancement | Status: new
Priority: normal | Milestone: 7.2.1
Component: Default | Version: svn-trunk
Keywords: | CPU: Unspecified
Platform: Unspecified |
-------------------------+-------------------------
Currently, v.what and the GUI query tool (based on v.what) can only find
one feature that is the nearest from the user-specified location. Most of
the time, this is OK, but when there are features overlapping each other,
the user cannot query them all. It would be great to be able to find all
features at a location, just like v.edit tool=select coor= using
Vect_select_lines_by_polygon() instead of Vect_find_line().

I attached a modified version of what.c for v.what and vector.py for GUI.
These files query multiple overlapping line features in one vector map,
but I wouldn't say that this is a good implementation because I'm not very
familiar with the GUI code, which works together with v.what.

--
Ticket URL: <https://trac.osgeo.org/grass/ticket/3292&gt;
GRASS GIS <https://grass.osgeo.org>

2

#3292: Query on spatially overlapped features in one vector map
--------------------------+-------------------------
  Reporter: hcho | Owner: grass-dev@…
      Type: enhancement | Status: new
  Priority: normal | Milestone: 7.2.1
Component: Default | Version: svn-trunk
Resolution: | Keywords:
       CPU: Unspecified | Platform: Unspecified
--------------------------+-------------------------
Changes (by hcho):

* Attachment "what.c" added.

v.what/what.c

--
Ticket URL: <https://trac.osgeo.org/grass/ticket/3292&gt;
GRASS GIS <https://grass.osgeo.org>

3

#3292: Query on spatially overlapped features in one vector map
--------------------------+-------------------------
  Reporter: hcho | Owner: grass-dev@…
      Type: enhancement | Status: new
  Priority: normal | Milestone: 7.2.1
Component: Default | Version: svn-trunk
Resolution: | Keywords:
       CPU: Unspecified | Platform: Unspecified
--------------------------+-------------------------
Changes (by hcho):

* Attachment "vector.py" added.

lib/python/script/vector.py

--
Ticket URL: <https://trac.osgeo.org/grass/ticket/3292&gt;
GRASS GIS <https://grass.osgeo.org>

4

#3292: Query on spatially overlapped features in one vector map
--------------------------+-------------------------
  Reporter: hcho | Owner: grass-dev@…
      Type: enhancement | Status: new
  Priority: normal | Milestone: 7.2.1
Component: Default | Version: svn-trunk
Resolution: | Keywords:
       CPU: Unspecified | Platform: Unspecified
--------------------------+-------------------------

Comment (by hcho):

Possible enhancements to the attached vector.py: Tree view for Features in
JSON

--
Ticket URL: <https://trac.osgeo.org/grass/ticket/3292#comment:1&gt;
GRASS GIS <https://grass.osgeo.org>

5

#3292: Query on spatially overlapped features in one vector map
--------------------------+-------------------------
  Reporter: hcho | Owner: grass-dev@…
      Type: enhancement | Status: new
  Priority: normal | Milestone: 7.2.1
Component: Default | Version: svn-trunk
Resolution: | Keywords:
       CPU: Unspecified | Platform: Unspecified
--------------------------+-------------------------

Comment (by annakrat):

Since this can potentially break scripts which rely on the JSON output, it
should be used only when requested, so a new flag (-m as 'multiple') would
solve this. And I think it makes sense to allow user to choose if they
want one or multiple results.

Also the json output must follow the same hierarchy for points, lines and
areas. Currently areas behave differently:

{{{
{
         "Coordinates": {
                 "East": "640122.510114",
                 "North": "235832.342168"
         },
         "Maps": [{
                 "Map": "bridges",
                 "Mapset": "PERMANENT",
                 "Features": [{
                         "Type": "Point",
                         "Id": 3932,
                         "Categories": [{
                                 "Layer": 1,
                                 "Category": 3932
                         }]
                 }]
         }]
}
}}}

{{{
{
         "Coordinates": {
                 "East": "640122.510114",
                 "North": "235832.342168"
         },
         "Maps": [{
                 "Map": "lakes",
                 "Mapset": "PERMANENT",
                 "Features": ,
                 "Type": "Area",
                 "Sq_Meters": 373.733,
                 "Hectares": 0.037,
                 "Acres": 0.092,
                 "Sq_Miles": 0.0001,
                 "Categories": [{
                         "Layer": 1,
                         "Category": 3813
                 }]
         }]
}
}}}

From brief testing, this command creates invalid JSON:
{{{v.what -d -j map=bridges@PERMANENT coordinates=641178,235089
distance=100}}}

It would be great if you could update the v.what implementation and I
could try to implement the tree for features in the GUI query dialog.

Please upload a diff instead of the entire file.

--
Ticket URL: <https://trac.osgeo.org/grass/ticket/3292#comment:2&gt;
GRASS GIS <https://grass.osgeo.org>

6

#3292: Query on spatially overlapped features in one vector map
--------------------------+-------------------------
  Reporter: hcho | Owner: grass-dev@…
      Type: enhancement | Status: new
  Priority: normal | Milestone: 7.4.0
Component: Vector | Version: svn-trunk
Resolution: | Keywords: query
       CPU: Unspecified | Platform: Unspecified
--------------------------+-------------------------
Changes (by annakrat):

* keywords: => query
* component: Default => Vector
* milestone: 7.2.1 => 7.4.0

--
Ticket URL: <https://trac.osgeo.org/grass/ticket/3292#comment:3&gt;
GRASS GIS <https://grass.osgeo.org>

7

#3292: Query on spatially overlapped features in one vector map
--------------------------+-------------------------
  Reporter: hcho | Owner: grass-dev@…
      Type: enhancement | Status: new
  Priority: normal | Milestone: 7.4.0
Component: Vector | Version: svn-trunk
Resolution: | Keywords: query
       CPU: Unspecified | Platform: Unspecified
--------------------------+-------------------------

Comment (by hcho):

Check r70700. -m flag should output valid JSON.

{{{
v.what -d map=bridges@PERMANENT coordinates=641178,235089 distance=100 -jm
}}}
outputs
{{{
{
    "Coordinates":{
       "East":"641178",
       "North":"235089"
    },
    "Maps":[
       {
          "Map":"bridges",
          "Mapset":"PERMANENT",
          "Features":[
             {
                "Feature_max_distance":100.000000,
                "Id":3985,
                "Type":"Point",
                "Left":0,
                "Right":0,
                "Categories":[
                   {
                      "Layer":1,
                      "Category":3985
                   }
                ]
             }
          ]
       }
    ]
}
}}}

Another example JSON output:
{{{
{
    "Coordinates":{
       "East":"3303269.05023",
       "North":"504062.5"
    },
    "Maps":[
       {
          "Map":"lfp",
          "Mapset":"tmp",
          "Features":[
             {
                "Type":"Line",
                "Id":537,
                "Length":55131.571388,
                "Categories":[
                   {
                      "Layer":1,
                      "Category":215646882
                   }
                ]
             },
             {
                "Type":"Line",
                "Id":328,
                "Length":67346.659403,
                "Categories":[
                   {
                      "Layer":1,
                      "Category":124085340
                   }
                ]
             },
             {
                "Type":"Line",
                "Id":536,
                "Length":69806.020152,
                "Categories":[
                   {
                      "Layer":1,
                      "Category":215016485
                   }
                ]
             },
             {
                "Type":"Line",
                "Id":183,
                "Length":97443.201949,
                "Categories":[
                   {
                      "Layer":1,
                      "Category":62974869
                   }
                ]
             },
             {
                "Type":"Line",
                "Id":326,
                "Length":86823.383054,
                "Categories":[
                   {
                      "Layer":1,
                      "Category":122824546
                   }
                ]
             },
             {
                "Type":"Line",
                "Id":535,
                "Length":83302.062710,
                "Categories":[
                   {
                      "Layer":1,
                      "Category":214386088
                   }
                ]
             }
          ]
       }
    ]
}
}}}

Now, it would be great if you could implement a new query button for
multiple queries.

--
Ticket URL: <https://trac.osgeo.org/grass/ticket/3292#comment:4&gt;
GRASS GIS <https://grass.osgeo.org>

8

#3292: Query on spatially overlapped features in one vector map
--------------------------+-------------------------
  Reporter: hcho | Owner: grass-dev@…
      Type: enhancement | Status: new
  Priority: normal | Milestone: 7.4.0
Component: Vector | Version: svn-trunk
Resolution: | Keywords: query
       CPU: Unspecified | Platform: Unspecified
--------------------------+-------------------------

Comment (by annakrat):

In [changeset:"70703" 70703]:
{{{
#!CommitTicketReference repository="" revision="70703"
pythonlib vector_what: add support for finding multiple features
implemented in v.what (see #3292)
}}}

--
Ticket URL: <https://trac.osgeo.org/grass/ticket/3292#comment:5&gt;
GRASS GIS <https://grass.osgeo.org>

9

#3292: Query on spatially overlapped features in one vector map
--------------------------+-------------------------
  Reporter: hcho | Owner: grass-dev@…
      Type: enhancement | Status: new
  Priority: normal | Milestone: 7.4.0
Component: Vector | Version: svn-trunk
Resolution: | Keywords: query
       CPU: Unspecified | Platform: Unspecified
--------------------------+-------------------------

Comment (by annakrat):

In [changeset:"70704" 70704]:
{{{
#!CommitTicketReference repository="" revision="70704"
wxGUI: return multiple features within query distance when querying vector
map, see #3292
}}}

--
Ticket URL: <https://trac.osgeo.org/grass/ticket/3292#comment:6&gt;
GRASS GIS <https://grass.osgeo.org>

10

#3292: Query on spatially overlapped features in one vector map
--------------------------+-------------------------
  Reporter: hcho | Owner: grass-dev@…
      Type: enhancement | Status: new
  Priority: normal | Milestone: 7.4.0
Component: Vector | Version: svn-trunk
Resolution: | Keywords: query
       CPU: Unspecified | Platform: Unspecified
--------------------------+-------------------------

Comment (by annakrat):

I implemented it in python scripting library and in GUI query dialog I put
it as default. I am not sure if we need to make it optional, it seems like
a useful behavior to me.

One more problem I found occurs with areas:
{{{
v.what map=lakes coordinates=635886.454183,223255.976096 distance=100 -jm
type=area
}}}

It's invalid json and there are duplicate records:
{{{
{
         "Coordinates": {
                 "East": "635886.454183",
                 "North": "223255.976096"
         },
         "Maps": [{
                 "Map": "lakes",
                 "Mapset": "PERMANENT",
                 "Features": [{,
                         "Type": "Area",
                         "Sq_Meters": 596589.425,
                         "Hectares": 59.659,
                         "Acres": 147.420,
                         "Sq_Miles": 0.2303,
                         "Categories": [{
                                 "Layer": 1,
                                 "Category": 8055
                         }]
                 }, {,
                         "Type": "Area",
                         "Sq_Meters": 596589.425,
                         "Hectares": 59.659,
                         "Acres": 147.420,
                         "Sq_Miles": 0.2303,
                         "Categories": [{
                                 "Layer": 1,
                                 "Category": 8055
                         }]
                 }, {,
                         "Type": "Area",
                         "Sq_Meters": 596589.425,
                         "Hectares": 59.659,
                         "Acres": 147.420,
                         "Sq_Miles": 0.2303,
                         "Categories": [{
                                 "Layer": 1,
                                 "Category": 8055
                         }]
                 }]
         }]
}
}}}
[https://grass.osgeo.org/programming7/sindex_8c.html#abd37487c40010a08f68621f37aad3e56
Vect_select_areas_by_polygon] documentation says ''Warning : values in
list may be duplicate'', but I have no idea why.

--
Ticket URL: <https://trac.osgeo.org/grass/ticket/3292#comment:7&gt;
GRASS GIS <https://grass.osgeo.org>

11

#3292: Query on spatially overlapped features in one vector map
--------------------------+-------------------------
  Reporter: hcho | Owner: grass-dev@…
      Type: enhancement | Status: new
  Priority: normal | Milestone: 7.4.0
Component: Vector | Version: svn-trunk
Resolution: | Keywords: query
       CPU: Unspecified | Platform: Unspecified
--------------------------+-------------------------

Comment (by hcho):

As for making it default, I agree with you that this behavior is useful
especially when the user doesn't know if he has overlapping features. He
may never know if there are multiple features until he uses the -m flag.

Selecting duplicate areas is fixed in r70711.

--
Ticket URL: <https://trac.osgeo.org/grass/ticket/3292#comment:8&gt;
GRASS GIS <https://grass.osgeo.org>

12

#3292: Query on spatially overlapped features in one vector map
--------------------------+-------------------------
  Reporter: hcho | Owner: grass-dev@…
      Type: enhancement | Status: new
  Priority: normal | Milestone: 7.4.0
Component: Vector | Version: svn-trunk
Resolution: | Keywords: query
       CPU: Unspecified | Platform: Unspecified
--------------------------+-------------------------

Comment (by hcho):

I just tried the new query and it's working. Would it be possible to group
results by map?

--
Ticket URL: <https://trac.osgeo.org/grass/ticket/3292#comment:9&gt;
GRASS GIS <https://grass.osgeo.org>

13

#3292: Query on spatially overlapped features in one vector map
--------------------------+-------------------------
  Reporter: hcho | Owner: grass-dev@…
      Type: enhancement | Status: new
  Priority: normal | Milestone: 7.4.0
Component: Vector | Version: svn-trunk
Resolution: | Keywords: query
       CPU: Unspecified | Platform: Unspecified
--------------------------+-------------------------

Comment (by annakrat):

Replying to [comment:9 hcho]:
> I just tried the new query and it's working. Would it be possible to
group results by map?

Yes, I will look into it later.

--
Ticket URL: <https://trac.osgeo.org/grass/ticket/3292#comment:10&gt;
GRASS GIS <https://grass.osgeo.org>

14

#3292: Query on spatially overlapped features in one vector map
--------------------------+-------------------------
  Reporter: hcho | Owner: grass-dev@…
      Type: enhancement | Status: new
  Priority: normal | Milestone: 7.4.0
Component: Vector | Version: svn-trunk
Resolution: | Keywords: query
       CPU: Unspecified | Platform: Unspecified
--------------------------+-------------------------

Comment (by hcho):

Replying to [comment:10 annakrat]:
> Replying to [comment:9 hcho]:
> > I just tried the new query and it's working. Would it be possible to
group results by map?
>
> Yes, I will look into it later.
>

Thanks. Keep in mind that v.what still has single query per map by
default. No grouping is needed for the default behavior. Still, I'm not
sure if it's a good idea to keep both queries in v.what. I believe that -m
is more user friendly and I'll use it almost always. Maybe, make it
default for the next release and remove the single query?

--
Ticket URL: <https://trac.osgeo.org/grass/ticket/3292#comment:11&gt;
GRASS GIS <https://grass.osgeo.org>