[postgis-tickets] [PostGIS] #2613: st_curvetoline not accurate

Fri Jan 17 15:33:19 PST 2014

#2613: st_curvetoline not accurate
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 Reporter:  hassony  |       Owner:  pramsey      
     Type:  defect   |      Status:  new          
 Priority:  high     |   Milestone:  PostGIS 2.0.5
Component:  postgis  |     Version:  2.0.x        
 Keywords:           |  
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 I'm using the st_curvetoline function on a CIRCULARSTRING which is a
 closed shape ('ellipse') - the start and end points are the same.
 However, performing the st_curvetoline on this geometry results in a
 slightly different start & end points which seems due to precision, which
 causes the st_isclosed to return false.

 The curved shape:
 CURVEPOLYGON(CIRCULARSTRING(-192.63 96.09,-236.72 -84.3,-262.33
 -256.89,-267.71 -409.94,-252.5 -533,-217.73 -617.69,-165.78
 -658.24,-100.19 -651.89,
 -25.42 -599.06,53.44 -503.37,130.99 -371.32,201.97 -211.92,261.53
 -36.04,305.62 144.35,331.23 316.94,336.61 469.99,321.4 593.05,286.64
 677.74,234.69
 718.29,169.09 711.94,94.32 659.11,15.47 563.42,-62.09 431.37,-133.07
 271.98,-192.63 96.09))

 The st_curvetoline result:

 POLYGON((-192.63 96.0899999999997,-217.49094913285 3.68
 269634278732,-237.787740682362 -89.8331676257292,-253.471477899904
 -184.232303998227,-262.33 -256.89,-266.542588544681
 -299.745998177307,-268.6472586
 8043 -342.757076350724,-268.638940072543
 -385.819617065606,-266.517652761274 -428.829878889538,-262.28850711356
 -471.684246334532,-255.961691511694 -
 514.279479475813,-252.5 -533,-251.658894336039
 -540.497237553746,-250.450929810044 -547.944173257723,-248.879016514363
 -555.322866791548,-246.9469413
 25809 -562.615542236198,-244.659358782741
 -569.804630897767,-242.021779871873 -576.872813631977,-239.040558751827
 -583.803062567522,-235.722877445405
  -590.578682127699,-232.076728537468 -597.183349251514,-228.110895920101
 -603.601152717363,-223.834933631445 -609.816631474565,-219.259142839184
 -615
 .814811890383,-214.394547024127 -621.581243822815,-209.252865423682
 -627.102035432256,-203.846484799182 -632.363886648156,-198.188429595094
 -637.3541
 21210052,-192.292330561993 -642.060717205791,-186.172391918886
 -646.47233603337,-179.843357134009 -650.578349716621,-173.320473406515
 -654.3688665089
 38,-166.619454934641 -657.834754723356,-165.78 -658.24,-158.27220787791
 -658.95577504603,-150.738337803383 -659.302298010905,-143.196539529318
 -659.2
 78734090452,-135.664981908341 -658.885140052217,-128.161809122446
 -658.122464098715,-120.705096972076 -656.992543583119,-113.312809329932
 -655.498100
 582921,-106.002754864432 -653.642735342207,-98.7925441370669
 -651.430917598351,-91.6995471770205 -648.867975814032,-84.7408516352421
 -645.96008434049
 5,-77.9332216188017 -642.714248543001,-71.2930573046867
 -639.138287924287,-64.8363554303397 -635.240817286701,-58.5786707561163
 -631.031225978388,-52
 .5350785925049 -626.519655273526,-46.7201384823841
 -621.716973941109,-41.1478591258075 -616.634752061133,-35.8316646318194
 -611.285233151256,-30.7843
 621785992 -605.681304671096,-26.0181111598484 -599.836466975206,-25.42
 -599.06,3.44582357033562 -567.161224310148,30.711678255014
 -533.884493262475,5
 6.3118782218929 -499.30997341677,80.1847503469395
 -463.520957819713,102.272782790188 -426.603665344624,122.522763546799
 -388.64703298265,130.99 -371.
 32,171.67174396928 -284.717936588532,208.055123152742
 -196.224030591009,240.052486803127 -106.05147157813,261.53
 -36.04,286.39094913285 56.3673036572
 126,306.687740682362 149.883167625729,322.371477899904
 244.282303998228,331.23 316.94,335.442588544681
 359.795998177307,337.54725868043 402.807076350
 724,337.538940072543 445.869617065606,335.417652761274
 488.879878889538,331.18850711356 531.734246334532,324.861691511694
 574.329479475813,321.4 593.
 05,320.560236709669 600.54576004541,319.353685438253
 607.991285887927,317.783252873448 615.368640603647,315.852722324855
 622.660051498878,313.5667446
 0966 629.847952926123,310.930826848408 636.915028601256,307.951319197864
 643.844253319975,304.635399552933 650.618933973003,300.991056254479
 657.2227
 49761254,297.027068844715 663.639791514071,292.752986916516
 669.854600015802,288.179107107612 675.852203248415,283.316448295087
 681.618152460394,278.
 176725049939 687.13855697505,272.772319415653
 692.400117654377,267.11625107877 697.390158937841,261.222146003329
 702.096659378912,255.104203604718 70
 6.508280605789,248.777162542044 710.614394636523,242.256265211411
 714.405109482761,235.55722102565 717.87129298041,234.69
 718.29,227.181974792479 719
 .006101264455,219.647855906502 719.352938617851,212.105793694379
 719.329676498623,204.573957644584 718.936370947256,197.070492609871
 718.173969471271
 ,189.613475094737 717.044308762603,182.220869707532
 715.550110272845,174.910485882149 713.694973657036,167.699934973538
 711.483368101773,160.60658783
 0409 708.920621558554,153.647532947331 706.01290790827,146.83953529706
 702.767232087792,140.198995942245 699.191413214458,133.741912523835
 695.294065
 749139,127.483840721359 691.084578743246,121.439856777931
 686.573093219684,115.62452118026 681.770477742239,110.051843581166
 676.688302232254,104.735
 249049093 671.33881009568,99.6875457259478
 665.734888727635,94.9208939711623 659.890038465538,94.3200000000002
 659.11,65.4365040332256 627.1840887415
 01,38.1543297185289 593.879387667767,12.5392022034703
 559.276130720833,-11.3471694261464 523.457680177571,-33.4472408088659
 486.510325822666,-53.7077
 709369901 448.523077068964,-62.0899999999999 431.37,-102.757449576671
 344.807495558579,-139.128492652405 256.353802273192,-171.115508198707
 166.22201
 2838594,-192.63 96.09))

 The versions I'm using:
 PostgreSQL 8.2.15 (Greenplum Database 4.2.5.1 build 1) on x86_64-unknown-
 linux-gnu, compiled by GCC gcc (GCC) 4.4.2 compiled on Apr 25 2013
 13:18:30

  POSTGIS="2.0.3 r11128" GEOS="3.3.8-CAPI-1.7.8" PROJ="Rel. 4.8.0, 6 March
 2012" LIBXML="2.7.8"

-- 
Ticket URL: <http://trac.osgeo.org/postgis/ticket/2613>
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