This is just a simple spatial intersection. Each line will intersect many
contour lines producing points, you can calculate the average elevation
points per line, calc min, max elev. Or save the line ID and elevation
points in another table to query later. Ask the Spatialite User Group.
http://g
I want to use SQLite in a GIS application where I create a database
>containing terrain data (coordinates, height).
>I would like to query this database with start and end points of a
>line and
>get a vector with all heights point along this line.
>I can, of course create a query for each point a
2009/8/23 P Kishor :
> If a line is expressed by (y = ax + c), you need to find all x,y that
> will satisfy that equation. So,
>
> SELECT x, y, z
> FROM terrain
> WHERE a*x - y + c = 0
General equation of line is a*x + b*y + c = 0. If you delete parameter
"b", you will have a problem with some pai
On Sun, Aug 23, 2009 at 12:08 AM, Itzchak
Raiskin wrote:
> Hi
> I want to use SQLite in a GIS application where I create a database
> containing terrain data (coordinates, height).
> I would like to query this database with start and end points of a line and
> get a vector with all heights point al
On Sun, Aug 23, 2009 at 11:34 AM, P Kishor wrote:
> On Sun, Aug 23, 2009 at 11:11 AM, Simon
> Slavin wrote:
>>
>> On 23 Aug 2009, at 5:00pm, P Kishor wrote:
>>
>>> WHERE a*x - y + c = 0
>>
>> Here's the problem. This works only when the equation is exact.
>
> Indeed. We already laid out those pres
On Sun, Aug 23, 2009 at 11:11 AM, Simon
Slavin wrote:
>
> On 23 Aug 2009, at 5:00pm, P Kishor wrote:
>
>> WHERE a*x - y + c = 0
>
> Here's the problem. This works only when the equation is exact.
Indeed. We already laid out those presumptions. One, your height
coverage has to be continuous as you
Itzchak Raiskin wrote:
> Hi
> I want to use SQLite in a GIS application where I create a database
> containing terrain data (coordinates, height).
> I would like to query this database with start and end points of a line and
> get a vector with all heights point along this line.
> I can, of course
On 23 Aug 2009, at 5:00pm, P Kishor wrote:
> WHERE a*x - y + c = 0
Here's the problem. This works only when the equation is exact.
Which under normal circumstances means that all the numbers fit neatly
with some imaginary integer formula. This isn't how real life works,
especially when
On Sun, Aug 23, 2009 at 12:08 AM, Itzchak
Raiskin wrote:
> Hi
> I want to use SQLite in a GIS application where I create a database
> containing terrain data (coordinates, height).
> I would like to query this database with start and end points of a line and
> get a vector with all heights point al
On Sun, Aug 23, 2009 at 01:08, Itzchak Raiskin wrote:
> Hi
> I want to use SQLite in a GIS application where I create a database
> containing terrain data (coordinates, height).
> I would like to query this database with start and end points of a line and
> get a vector with all heights point alon
On Sun, 23 Aug 2009, Itzchak Raiskin wrote:
> I want to use SQLite in a GIS application where I create a database
> containing terrain data (coordinates, height). I would like to query this
> database with start and end points of a line and get a vector with all
> heights point along this line. I
On 23/08/2009 3:08 PM, Itzchak Raiskin wrote:
> Hi
> I want to use SQLite in a GIS application where I create a database
> containing terrain data (coordinates, height).
> I would like to query this database with start and end points of a line and
> get a vector with all heights point along this li
2009/8/23 Itzchak Raiskin :
> Hi
> I want to use SQLite in a GIS application where I create a database
> containing terrain data (coordinates, height).
> I would like to query this database with start and end points of a line and
> get a vector with all heights point along this line.
> I can, of co
Hi
I want to use SQLite in a GIS application where I create a database
containing terrain data (coordinates, height).
I would like to query this database with start and end points of a line and
get a vector with all heights point along this line.
I can, of course create a query for each point along
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