[GRASS-dev] v.select features without category skipped

lucadelu · November 17, 2016, 1:11pm

Hi devs,

this morning I got a problem with v.select, I don't understand if is a
bug or what... I repeated the procedure with north carolina dataset

g.region vect=zipcodes -ap

v.mkgrid map=zipcodes_grid box=10000,10000

v.category zipcodes_grid opt=report
Layer/table: 1/zipcodes_grid
type count min max
point 0 0 0
line 0 0 0
boundary 0 0 0
centroid 42 1 42
area 0 0 0
face 0 0 0
kernel 0 0 0
all 42 1 42

v.select ain=zipcodes_grid bin=zipcodes operator=touches
out=zipcodes_grid_final --o
WARNING: Vector map <zipcodes_grid_final> already exists and will be
overwritten
Processing features...
100%
Processing areas...
100%
Writing selected features...
100%
Writing attributes...
WARNING: Array of values to select from column <cat> is empty
WARNING: Unable to copy table for layer 1
DBMI-SQLite driver error:
Unable to create index:
create unique index if not exists zipcodes_grid_final_cat on
zipcodes_grid_final ( cat )
no such table: main.zipcodes_grid_final

DBMI-SQLite driver error:
Unable to create index:
create unique index if not exists zipcodes_grid_final_cat on
zipcodes_grid_final ( cat )
no such table: main.zipcodes_grid_final

WARNING: Unable to create index
WARNING: 97 features from <zipcodes_grid@user1> without category skipped
Building topology for vector map <zipcodes_grid_final@user1>...
Registering primitives...
0 primitives registered
0 vertices registered
Building areas...
100%
0 areas built
0 isles built
Attaching islands...
Attaching centroids...
Number of nodes: 0
Number of primitives: 0
Number of points: 0
Number of lines: 0
Number of boundaries: 0
Number of centroids: 0
Number of areas: 0
Number of isles: 0
v.select complete. 0 features written to output.

is someone able to reproduce the error? if yes I will open a ticket (I
tested both grass70 and grass72, I didn't with trunk)

--
ciao
Luca

www.lucadelu.org

hellik · November 17, 2016, 1:30pm

Luca Delucchi wrote

Hi devs,

this morning I got a problem with v.select, I don't understand if is a
bug or what... I repeated the procedure with north carolina dataset

g.region vect=zipcodes -ap

v.mkgrid map=zipcodes_grid box=10000,10000

v.category zipcodes_grid opt=report
Layer/table: 1/zipcodes_grid
type count min max
point 0 0 0
line 0 0 0
boundary 0 0 0
centroid 42 1 42
area 0 0 0
face 0 0 0
kernel 0 0 0
all 42 1 42

v.select ain=zipcodes_grid bin=zipcodes operator=touches
out=zipcodes_grid_final --o
WARNING: Vector map
<zipcodes_grid_final>
already exists and will be
overwritten
Processing features...
100%
Processing areas...
100%
Writing selected features...
100%
Writing attributes...
WARNING: Array of values to select from column
<cat>
is empty
WARNING: Unable to copy table for layer 1
DBMI-SQLite driver error:
Unable to create index:
create unique index if not exists zipcodes_grid_final_cat on
zipcodes_grid_final ( cat )
no such table: main.zipcodes_grid_final

DBMI-SQLite driver error:
Unable to create index:
create unique index if not exists zipcodes_grid_final_cat on
zipcodes_grid_final ( cat )
no such table: main.zipcodes_grid_final

WARNING: Unable to create index
WARNING: 97 features from <zipcodes_grid@user1> without category
skipped
Building topology for vector map <zipcodes_grid_final@user1>...
Registering primitives...
0 primitives registered
0 vertices registered
Building areas...
100%
0 areas built
0 isles built
Attaching islands...
Attaching centroids...
Number of nodes: 0
Number of primitives: 0
Number of points: 0
Number of lines: 0
Number of boundaries: 0
Number of centroids: 0
Number of areas: 0
Number of isles: 0
v.select complete. 0 features written to output.

is someone able to reproduce the error? if yes I will open a ticket (I
tested both grass70 and grass72, I didn't with trunk)

tested with

System Info
GRASS version: 7.3.svn
GRASS SVN revision: r69838
Build date: 2016-11-17
Build platform: x86_64-w64-mingw32
GDAL: 2.1.2
PROJ.4: 4.9.3
GEOS: 3.5.0
SQLite: 3.14.1
Python: 2.7.5
wxPython: 2.8.12.1
Platform: Windows-8-6.2.9200 (OSGeo4W)

v.select ainput=zipcodes_grid@user1 binput=zipcodes_wake@PERMANENT
output=zipcodes_grid_final operator=touches
Processing features...
Processing areas...
Writing selected features...
Writing attributes...
WARNING: Array of values to select from column <cat> is empty
WARNING: Unable to copy table for layer 1
WARNING: Unable to create index
WARNING: 97 features from <zipcodes_grid@user1> without category skipped
Building topology for vector map <zipcodes_grid_final@user1>...
Registering primitives...
0 primitives registered
0 vertices registered
Building areas...
0 areas built
0 isles built
Attaching islands...
Attaching centroids...
Number of nodes: 0
Number of primitives: 0
Number of points: 0
Number of lines: 0
Number of boundaries: 0
Number of centroids: 0
Number of areas: 0
Number of isles: 0
v.select complete. 0 features written to output.

same here

-----
best regards
Helmut
--
View this message in context: http://osgeo-org.1560.x6.nabble.com/v-select-features-without-category-skipped-tp5296258p5296263.html
Sent from the Grass - Dev mailing list archive at Nabble.com.

mlennert · November 17, 2016, 5:06pm

On 17/11/16 14:11, Luca Delucchi wrote:

Hi devs,

this morning I got a problem with v.select, I don't understand if is a
bug or what... I repeated the procedure with north carolina dataset

g.region vect=zipcodes -ap

v.mkgrid map=zipcodes_grid box=10000,10000

v.category zipcodes_grid opt=report
Layer/table: 1/zipcodes_grid
type count min max
point 0 0 0
line 0 0 0
boundary 0 0 0
centroid 42 1 42
area 0 0 0
face 0 0 0
kernel 0 0 0
all 42 1 42

v.select ain=zipcodes_grid bin=zipcodes operator=touches
out=zipcodes_grid_final --o
WARNING: Vector map <zipcodes_grid_final> already exists and will be
overwritten
Processing features...
100%
Processing areas...
100%
Writing selected features...
100%
Writing attributes...
WARNING: Array of values to select from column <cat> is empty

i.e. no features found which is logical, as there are no zipcode areas that touch a grid area. 'touches' is normally defined as [1]

"a touches b: they have at least one boundary point in common, but no interior points."

Try with intersects, overlaps, etc.

I agree though that the error message is very unclear. After the "Array of values ... is empty" it should just stop. After a very rapid look at main.c of v.select it seems to me that it doesn't check the result of the selection and just goes on trying to write a new file...

Moritz

[1] https://en.wikipedia.org/wiki/DE-9IM

mlennert · November 17, 2016, 5:38pm

On 17/11/16 18:06, Moritz Lennert wrote:

On 17/11/16 14:11, Luca Delucchi wrote:

Hi devs,

this morning I got a problem with v.select, I don't understand if is a
bug or what... I repeated the procedure with north carolina dataset

g.region vect=zipcodes -ap

v.mkgrid map=zipcodes_grid box=10000,10000

v.category zipcodes_grid opt=report
Layer/table: 1/zipcodes_grid
type count min max
point 0 0 0
line 0 0 0
boundary 0 0 0
centroid 42 1 42
area 0 0 0
face 0 0 0
kernel 0 0 0
all 42 1 42

v.select ain=zipcodes_grid bin=zipcodes operator=touches
out=zipcodes_grid_final --o
WARNING: Vector map <zipcodes_grid_final> already exists and will be
overwritten
Processing features...
100%
Processing areas...
100%
Writing selected features...
100%
Writing attributes...
WARNING: Array of values to select from column <cat> is empty

i.e. no features found which is logical, as there are no zipcode areas
that touch a grid area. 'touches' is normally defined as [1]

"a touches b: they have at least one boundary point in common, but no
interior points."

Try with intersects, overlaps, etc.

I agree though that the error message is very unclear. After the "Array
of values ... is empty" it should just stop. After a very rapid look at
main.c of v.select it seems to me that it doesn't check the result of
the selection and just goes on trying to write a new file...

Try the attached patch. Not very elegant and not well tested, but seems to work for me.

Moritz

(attachments)

v_select_no_features.diff (3.75 KB)

lucadelu · December 20, 2016, 3:02pm

On 17 November 2016 at 18:06, Moritz Lennert
<mlennert@club.worldonline.be> wrote:

i.e. no features found which is logical, as there are no zipcode areas that
touch a grid area. 'touches' is normally defined as [1]

"a touches b: they have at least one boundary point in common, but no
interior points."

Try with intersects, overlaps, etc.

yes with intersects it work as expected...

Moritz

--
ciao
Luca

www.lucadelu.org

lucadelu · December 20, 2016, 3:03pm

On 17 November 2016 at 18:38, Moritz Lennert
<mlennert@club.worldonline.be> wrote:

Try the attached patch. Not very elegant and not well tested, but seems to
work for me.

It work also for me (I tested in trunk) and I like it

Moritz

--
ciao
Luca

www.lucadelu.org

mlennert · December 20, 2016, 3:08pm

On 20/12/16 16:03, Luca Delucchi wrote:

On 17 November 2016 at 18:38, Moritz Lennert
<mlennert@club.worldonline.be> wrote:

Try the attached patch. Not very elegant and not well tested, but seems to
work for me.

It work also for me (I tested in trunk) and I like it

You can go ahead and commit to trunk, unless someone objects. At least this way it gets some testing.

Moritz

lucadelu · December 20, 2016, 3:18pm

On 20 December 2016 at 16:08, Moritz Lennert
<mlennert@club.worldonline.be> wrote:

You can go ahead and commit to trunk, unless someone objects. At least this
way it gets some testing.

are you sure? you should submit it :-/

Moritz

--
ciao
Luca

www.lucadelu.org

mlennert · December 20, 2016, 3:36pm

On 20/12/16 16:18, Luca Delucchi wrote:

On 20 December 2016 at 16:08, Moritz Lennert
<mlennert@club.worldonline.be> wrote:

You can go ahead and commit to trunk, unless someone objects. At least this
way it gets some testing.

are you sure? you should submit it :-/

I had hoped to put the work on you...

But it's done: r70103.

But we should keep this in mind and observe whether this does not cause any issues. Maybe open a ticket ?

Moritz

wenzeslaus · December 20, 2016, 4:14pm

On Tue, Dec 20, 2016 at 10:36 AM, Moritz Lennert <
mlennert@club.worldonline.be> wrote:

On 20/12/16 16:18, Luca Delucchi wrote:

On 20 December 2016 at 16:08, Moritz Lennert
<mlennert@club.worldonline.be> wrote:

You can go ahead and commit to trunk, unless someone objects. At least
this
way it gets some testing.

are you sure? you should submit it :-/

I had hoped to put the work on you...

But it's done: r70103.

But we should keep this in mind and observe whether this does not cause
any issues. Maybe open a ticket ?

Isn't an empty vector map an expected result in this case? What happens
when you do this in GUI (where output is added automatically to Map
Display)? Ticket might be appropriate.

mlennert · December 20, 2016, 4:57pm

On 20/12/16 17:14, Vaclav Petras wrote:

On Tue, Dec 20, 2016 at 10:36 AM, Moritz Lennert
<mlennert@club.worldonline.be <mailto:mlennert@club.worldonline.be>> wrote:

    On 20/12/16 16:18, Luca Delucchi wrote:

        On 20 December 2016 at 16:08, Moritz Lennert
        <mlennert@club.worldonline.be
        <mailto:mlennert@club.worldonline.be>> wrote:

            You can go ahead and commit to trunk, unless someone
            objects. At least this
            way it gets some testing.

        are you sure? you should submit it :-/

    I had hoped to put the work on you...

    But it's done: r70103.

    But we should keep this in mind and observe whether this does not
    cause any issues. Maybe open a ticket ?

Isn't an empty vector map an expected result in this case? What happens
when you do this in GUI (where output is added automatically to Map
Display)? Ticket might be appropriate.

https://trac.osgeo.org/grass/ticket/3226