[Qgis-user] Qgis - create attribute at regular interval along Z axis based on above attribute elevation

[Nyall Dawson]

On Sat, 3 Nov 2018 at 11:28, Francois Chartier <fra.chartier at gmail.com> wrote:
>
> Hi,
>
> I am using Microsoft Access to populate a data set at regular intervals along the vertical axis between two elevation ranges (50 to 350 masl) and have the attribute (which does not exist) of that elevation to become the attribute of the above data point.  example at 124.4, attribute at location 1 is A,  therefore at 124 attribute becomes A, and this down to the next data point at example 121.6 masl where it is B (you will at location 1: at 124=A, 123=A, 122=A).
> The goal being to interpolate different elevation slices at regular intervals as data points are not all at the same elevations depending on location.
> I am able to do this with a Cross Join query in access and then removing any intervals above top and bottom.  this is quite fastiduous, and i am wondering if i can do this straight in qgis, or
> if i can run an interpolation with a condition that the value at location x,y equals the next above attribute value.  this would keep the attribute table much smaller.

There's nothing directly available out of the box which does this, but
it sounds like the perfect candidate for a little Python Processing
script algorithm, if you've got some Python experience or can contract
someone who has.

Alternatively, you may be able to create a graphical model which also
does this, using a combination of:
- set Z value (to set the first feature's z values)
- array of translated features (to create the "stacked" features at
different heights)
- field calculator (to populate the attribute values)

Nyall


>
> thanks
> F
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