PowerPC failure in st_geod_area

[rsbivand]

@edzer Failure reported r-spatial/spdep#154 by @barracuda156 on PowerPC, there causing a failure in an spdep vignette. It is triggered on PowerPC by:

library(sf)
nc = st_read(system.file("shapes/sids.shp", package="spData")[1])
st_crs(nc) <- "+proj=longlat +datum=NAD27"
library(lwgeom)
st_geod_area(nc)

suggesting an incorrect conversion from WKB in liblwgeom on that platform.

[rsbivand]

See also r-spatial/spdep#154 (comment).

[edzer]

Yes, this is hardcoded here: https://github.com/r-spatial/lwgeom/blob/master/src/postgis_config.h.in#L25 , and is not being set (AFAICT) in the configure script.

[edzer]

... on the positive side, it took over 6 years to surface!

[rsbivand]

Better late than never! Someone will manufacture a big-endian ARM sometime - I think this entered the code after the last SPARC test platform failed.

[edzer]

Someone with a bigendian machine needs to test whether this now works!

[rsbivand]

@barracuda156 could you please check the current state of lwgeom?

[barracuda156]

Someone with a bigendian machine needs to test whether this now works!

@edzer @rsbivand Will test today, sure.

[edzer]

That would be great; the last commit should have fixed this.

[barracuda156]

@edzer @rsbivand Looks like version from 304022f works:

> library(sf)
Linking to GEOS 3.12.1, GDAL 3.8.5, PROJ 9.4.0; sf_use_s2() is TRUE
> nc = st_read(system.file("shapes/sids.shp", package="spData")[1])
Reading layer `sids' from data source 
  `/opt/local/Library/Frameworks/R.framework/Versions/4.4/Resources/library/spData/shapes/sids.shp' 
  using driver `ESRI Shapefile'
Simple feature collection with 100 features and 22 fields
Geometry type: MULTIPOLYGON
Dimension:     XY
Bounding box:  xmin: -84.32385 ymin: 33.88199 xmax: -75.45698 ymax: 36.58965
CRS:           NA
> st_crs(nc) <- "+proj=longlat +datum=NAD27"
> library(lwgeom)
Linking to liblwgeom 3.0.0beta1 r16016, GEOS 3.12.1, PROJ 9.4.0

Attaching package: ‘lwgeom’

The following object is masked from ‘package:sf’:

    st_perimeter

> st_geod_area(nc)
Units: [m^2]
  [1] 1137388604  611077263 1423489919  694546292 1520740530  967727952
  [7]  615942210  903650119 1179347051 1232769242 1136287383 1524655447
 [13] 1427072339 1085967384  718190417 1894045426  524418608 1986966652
 [19]  812293946  626337436  439717946  640703090  863300187 1276536764
 [25] 1084141138 1697937846 1109973986 1800646340 1036414044  770546970
 [31] 1423171283  585232978 1311628320 1225109692  800263351 1186420419
 [37] 2194592880 1179139746 1550312884  690606074  665152821 1457875905
 [43] 1340538971 1005743617  988324117 1163892506 2019778925 1810512144
 [49]  944425951 1350102629 1685154840 1068192109 1691487743 2082117118
 [55] 1447094476  943881740 2045540782 1420919020  707671880  653368537
 [61] 1471077596 1436135571 1550981080 1186028306  788535203 1265443511
 [67] 1829439189 1447873644  918216585 1312723474 1043728456  961860121
 [73]  781910957 1046066043  986730350  917752685  601326678 1321916259
 [79] 2437929994  833538942 1210326313 1738550168 1228689798 1648412173
 [85] 1400582685  995107225 1678077407 2071844302 1228274216  519198288
 [91] 1784932020  808600209 1978619669 2439553215 1264050755 2288682896
 [97] 2181174167 2450241815  430695499 2165843695

Thanks for fixing it!

[edzer]

Thanks for confirming!