0025961: Wrong result of projection point on the ellipse

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Summary	0025961: Wrong result of projection point on the ellipse

Revision	2015-03-20 11:30 by nbv
Steps To Reproduce	Draw[]> ellipse ce 15793.1884865181, -5613.90386522167, -2450 0.566529531797242, 0.824041436823172, 4.04832179340053e-023 249106758.909924, 18 Draw[]> dset x1 15810.404909670384 Draw[]> dset y1 -5625.7401757733878 Draw[]> dset z1 -2468.0000000000000 Draw[]> proj ce x1 y1 z1 # parameter 1 = 3.141592653589798 #ext_1 parameter 2 = 4.7123890642550172 #ext_2 parameter 3 = 6.2831853071795809 #ext_3 parameter 4 = 6.2831853071795809 #ext_4 Draw[]> length ext_1 The length ext_1 is 249106779.80259019 Draw[]> length ext_2 The length ext_2 is 36.000000000000043 Draw[]> length ext_3 The length ext_3 is 249106738.01725906 Draw[]> length ext_4 The length ext_4 is 249106738.01725906 I.e. minimal distance between ellipse and point is 36.000000000000043. However, try the following script: Draw[]> cval ce pi/2 xx yy zz Draw[]> dset sd (xx-x1)(xx-x1)+(yy-y1)(yy-y1)+(zz-z1)*(zz-z1) # 436.50347299786017 Draw[]> dval sqrt(sd) # 20.892665531182473 Consequently, there is a point nearer to the given with distance 20.892665531182473.

Revision	2015-03-20 11:29 by nbv
Steps To Reproduce	Draw[]> ellipse ce 15793.1884865181, -5613.90386522167, -2450 0.566529531797242, 0.824041436823172, 4.04832179340053e-023 249106758.909924, 18 Draw[]> dset x1 15810.404909670384 Draw[]> dset y1 -5625.7401757733878 Draw[]> dset z1 -2468.0000000000000 Draw[]> proj ce x1 y1 z1 # parameter 1 = 3.141592653589798 #ext_1 parameter 2 = 4.7123890642550172 #ext_2 parameter 3 = 6.2831853071795809 #ext_3 parameter 4 = 6.2831853071795809 #ext_4 Draw[]> length ext_1 The length ext_1 is 249106779.80259019 Draw[]> length ext_2 The length ext_2 is 36.000000000000043 Draw[]> length ext_3 The length ext_3 is 249106738.01725906 Draw[]> length ext_4 The length ext_4 is 249106738.01725906 I.e. minimal distance between ellipse and point is 36.000000000000043. However, try the following script: Draw[]> cval ce pi/2 xx yy zz Draw[]> dset sd (xx-x1)(xx-x1)+(yy-y1)(yy-y1)+(zz-z1)*(zz-z1) 0000436.50347299786017 Draw[]> dval sqrt(sd) 0000020.892665531182473 Consequently, there is a point nearer to the given with distance 20.892665531182473.