Failure to create convex hull

[Bee-BeanBag]

Pipeline stage where the bug occurs

Ingest — reading or regridding radar files

Adapt version

adapt 0.1.3.post1

Radar site and data source

No response

What happened?

Got the error message listed when processing radar files

Steps to reproduce

Run run-nexrad
Let the radar files process
Error message is produced

Full error message or traceback

2026-06-08 12:13:42 - adapt.runtime.processor - INFO - Processing: KHTX20250502_190617_V06
2026-06-08 12:13:42 - adapt.visualization.plotter - INFO - Plot saved: /home/blamsma/adapt_output/KHTX/plots/20250502/KHTX_reflectivity_190134.png
2026-06-08 12:13:42 - adapt.visualization.plotter - INFO - Plot saved: /home/blamsma/adapt_output/KHTX/plots/20250502/KHTX_reflectivity_190134.png (total: 26)
2026-06-08 12:13:51 - adapt.runtime.orchestrator - INFO - Status: D=UP P=UP Q=20 [0/50]
2026-06-08 12:13:59 - adapt.modules.ingest.module - INFO - Saved regridded NetCDF: /home/blamsma/adapt_output/KHTX/gridnc/20250502/KHTX20250502_190617_V06.nc
2026-06-08 12:13:59 - adapt.modules.projection.module - WARNING - Concave hull failed: QH6154 Qhull precision error: Initial simplex is flat (facet 1 is coplanar with the interior point)

While executing:  | qhull d Qc Qbb Qt Q12 Qz
Options selected for Qhull 2020.2.r 2020/08/31:
  run-id 611995187  delaunay  Qcoplanar-keep  Qbbound-last  Qtriangulate
  Q12-allow-wide  Qz-infinity-point  _pre-merge  _zero-centrum  Qinterior-keep
  Pgood  _max-width  5  Error-roundoff 3e-13  _one-merge 2.1e-12
  Visible-distance 6e-13  U-max-coplanar 6e-13  Width-outside 1.2e-12
  _wide-facet 3.6e-12  _maxoutside 2.4e-12

The input to qhull appears to be less than 3 dimensional, or a
computation has overflowed.

Qhull could not construct a clearly convex simplex from points:
- p1(v4): 2.1e+02 1.9e+02   8.8
- p5(v3): 2.1e+02 1.9e+02 2.2e+02
- p4(v2): 2.2e+02 1.9e+02    45
- p0(v1): 2.1e+02 1.9e+02     0

The center point is coplanar with a facet, or a vertex is coplanar
with a neighboring facet.  The maximum round off error for
computing distances is 3e-13.  The center point, facets and distances
to the center point are as follows:

center point    214.1      189    67.62

facet p5 p4 p0 distance=    0
facet p1 p4 p0 distance=    0
facet p1 p5 p0 distance=    0
facet p1 p5 p4 distance=    0

These points either have a maximum or minimum x-coordinate, or
they maximize the determinant for k coordinates.  Trial points
are first selected from points that maximize a coordinate.

The min and max coordinates for each dimension are:
  0:       212       217  difference=    5
  1:       189       189  difference=    0
  2:         0       217  difference=  217

If the input should be full dimensional, you have several options that
may determine an initial simplex:
  - use 'QJ'  to joggle the input and make it full dimensional
  - use 'QbB' to scale the points to the unit cube
  - use 'QR0' to randomly rotate the input for different maximum points
  - use 'Qs'  to search all points for the initial simplex
  - use 'En'  to specify a maximum roundoff error less than 3e-13.
  - trace execution with 'T3' to see the determinant for each point.

If the input is lower dimensional:
  - use 'QJ' to joggle the input and make it full dimensional
  - use 'Qbk:0Bk:0' to delete coordinate k from the input.  You should
    pick the coordinate with the least range.  The hull will have the
    correct topology.
  - determine the flat containing the points, rotate the points
    into a coordinate plane, and delete the other coordinates.
  - add one or more points to make the input full dimensional.
, falling back to dilation

Configuration file (redact credentials)

Environment

linux/python 11.3/installed from source archive 0.1.3.post1

Checklist

• I checked the documentation and existing issues
• I can reproduce this consistently
• This occurs on the latest release

[RBhupi]

This issue is not a serious error. It's a warning that happens when the cell is too small for computing the convex hull. I need to catch it and may be mark those cells with a flag.