[GRASSLIST:10257] Re: v.in.ascii quirk

[Stuart Edwards]

Maciek
On page 3 of the v.in.ascii man page there is a cryptic note near the  
end:

'The 'point' string (or some similar entry) is required to generate a  
database table.  When simply piping the coordinates (and optionally  
height) without additional column(s) into v.in.ascii, only the vector  
map geometry will be generated'

So it seems to be partly a feature and partly a bug, and there  
probably needs to be some review of the function and its GUI/CLI  
relationship as well as clarification of  the man page.  The above is  
actually the only reference I have seen to the creation of a database  
table in documentation. Other information is available by reverse  
engineering the error messages, but that's a hard way to go.  It  
would seem useful to have database table generation as an option for  
all v.in.ascii input.  Confirmation that a database table had been  
set up (or not) would be helpful in the output stream when the  
command is run.

Thanks for looking into this.

Stuart


On Feb 10, 2006, at 12:21 PM, Maciek Sieczka wrote:

> Stuart,
>
> Seems we've found a bug, CCing to dev list.
>
>
> On Fri, 10 Feb 2006 11:30:29 -0500
> Stuart Edwards <sedwards2 at cinci.rr.com> wrote:
>
>> Yes, I did have the ' ' in place.  However when I run the GUI
>> without them, the .dbf file still is not created.
>>
>> v.in.ascii input=/Users/stu/Desktop/grasstest/fivepoints output=fp
>> format=point 'fs='\'' '\''' skip=1 'columns=x double, y double, z
>> double,' x=1 y=2 z=3 cat=0 -z
>
> To specify space as field seperator you can also use: space  
> (literally).
>
>
>> The GUI appears to have inserted '  ' around the whole phrase
>> starting at 'columns rather than just around 'x double, etc.
>
> Strange indeed. I haven't noticed it before. I have doublechecked and
> interestingly v.in.ascii works in such form too, also from CLI. Could
> Developers please comment what is this? Manual tells to use columns='x
> double, y double', not 'columns=x double, y double'. Why both are
> supported?
>
>
>> tried leaving the ' '  out of the field separator field with similar
>> results.
>
> That should work as well as space.
>
>
>
> Getting back to main problem: what I think is the actuall reason for
> your dbf file being not created, is that v.in.ascii simply doesn't
> create dbf file for 3D vectors it creates. Trying to sort out your  
> case
> I have just noticed it. I don't know if this is a feature or a bug.
> Developers - is there any reason why 3D vectors should not have
> attribute tables?
>
> Please see this example:
>
> ### Creating 2D vector there is a dbf created:
>
> $ echo "200.0 200.0 999.0" | v.in.ascii output=onepoint fs=space
> columns='x double, y double, z double' x=1 y=2
> $ v.info -c onepoint
> Displaying column types/names for database connection of layer 1:
> INTEGER|cat
> DOUBLE PRECISION|x
> DOUBLE PRECISION|y
> DOUBLE PRECISION|z
>
>
>
> ### But creating a 3D vector, dbf isn't created:
>
> $ echo "200.0 200.0 999.0" | v.in.ascii -z output=onepoint fs=space
> columns='x double, y double, z double' x=1 y=2 z=3
>
> $ v.info -c onepoint
> Database connection for map <onepoint> is not defined in DB file
>
>
>
>
> ### Another thing - if I don't put -z flag but still specify the  
> number
> ### of column for z coordinate, there's no error message, while
> ### I guess there should be:
>
> $ echo "200.0 200.0 999.0" | v.in.ascii output=onepoint fs=space
> columns='x double, y double, z double' x=1 y=2 z=3
> Maximum input row length: 18
> Maximum number of columns: 3
> Minimum number of columns: 3
> Building topology ...
> 1 primitives registered
> Building areas:  100%
> 0 areas built
> 0 isles built
> Attaching islands:
> Attaching centroids:  100%
> Topology was built.
> Number of nodes     :   1
> Number of primitives:   1
> Number of points    :   1
> Number of lines     :   0
> Number of boundaries:   0
> Number of centroids :   0
> Number of areas     :   0
> Number of isles     :   0
>
> Maciek
>
> --------------------
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