svg: Rounding errors in Y labels

[Ploppz]

The only thing that is visible of the top-most number os 0000000005, but it's actually 5.60000000005.

Here is the svg file: http://sprunge.us/QdSTRO

Here is the input data to plotlib:

[(10.0, 5.554613094409367), (15.0, 5.571373799732846), (20.0, 5.580786175835321), (25.0, 5.594389457136185), (30.0, 5.588413866453277), (35.0, 5.581090728388583), (40.0, 5.564882932873482), (45.0, 5.5655230910515785), (50.0, 5.575694697314061), (55.0, 5.563091468885199), (60.0, 5.505139387304649), (65.0, 5.435932668847201), (70.0, 5.392844844207445), (75.0, 5.375070392542875), (80.0, 5.370750095478286), (85.0, 5.355376048261111), (90.0, 5.348519533974179), (95.0, 5.344626082423696), (100.0, 5.3274562508487024), (105.0, 5.329445069896911), (110.0, 5.330588028449412), (115.0, 5.335541125490482), (120.0, 5.32486693110636), (125.0, 5.326145859928657), (130.0, 5.3267627195905245), (135.0, 5.324000652981454), (140.0, 5.327175540775914), (145.0, 5.326936653662645), (150.0, 5.326319101633424), (155.0, 5.3195335123314775), (160.0, 5.318547022604354), (165.0, 5.318984347429394), (170.0, 5.317016756493654), (175.0, 5.320569820967218), (180.0, 5.321774086633875), (185.0, 5.3192970755289), (190.0, 5.308293371083831), (195.0, 5.286882630232821), (200.0, 5.264732108073603), (205.0, 5.254215082718998), (210.0, 5.242928735217475), (215.0, 5.229751139000503), (220.0, 5.202672283250928), (225.0, 5.180185883522078), (230.0, 5.156744670958561), (235.0, 5.134800944115094), (240.0, 5.127834870263292), (245.0, 5.121960601961146), (250.0, 5.115420107250173), (255.0, 5.1122765198698215), (260.0, 5.107215561118251), (265.0, 5.09911659020747), (270.0, 5.088330837894482), (275.0, 5.085926681262303), (280.0, 5.084239392471663), (285.0, 5.083673161411417), (290.0, 5.084211846974766), (295.0, 5.081707528453846), (300.0, 5.078245582248812)]
[(10.0, 5.554613094409367), (15.0, 5.571373799732846), (20.0, 5.580786175835321), (25.0, 5.594389457136185), (30.0, 5.588413866453277), (35.0, 5.585615659886031), (40.0, 5.587206724645493), (45.0, 5.571298729005933), (50.0, 5.558131825575247), (55.0, 5.544393316154019), (60.0, 5.53813614296059), (65.0, 5.523535700145619), (70.0, 5.4996913881052105), (75.0, 5.472378149492847), (80.0, 5.45374886101448), (85.0, 5.4324287369128195), (90.0, 5.410797420874291), (95.0, 5.393886671682631), (100.0, 5.361498295387429), (105.0, 5.320841464177755), (110.0, 5.277655355217769), (115.0, 5.242304398506202), (120.0, 5.220685015560172), (125.0, 5.197350800910618), (130.0, 5.180128027249545), (135.0, 5.165155622245212), (140.0, 5.157291822432492), (145.0, 5.160809304386804), (150.0, 5.1621050182918875), (155.0, 5.164784237269466), (160.0, 5.170044410029799), (165.0, 5.176610149099485), (170.0, 5.178943153694296), (175.0, 5.180969369533339), (180.0, 5.181202553209083), (185.0, 5.180421437704337), (190.0, 5.183487260078211), (195.0, 5.190838759095146), (200.0, 5.19805536865893), (205.0, 5.205331656977181), (210.0, 5.211848936948826), (215.0, 5.215886880659793), (220.0, 5.2191099964160355), (225.0, 5.214903056232922), (230.0, 5.209356626646803), (235.0, 5.210631952871428), (240.0, 5.212151991487046), (245.0, 5.214216204923996), (250.0, 5.206883052633969), (255.0, 5.207739240362648), (260.0, 5.207163350519838), (265.0, 5.205506780136554), (270.0, 5.207203657870471), (275.0, 5.206951561696365), (280.0, 5.208947475530317), (285.0, 5.20313975184542), (290.0, 5.204589733890532), (295.0, 5.205217982298412), (300.0, 5.202972315747025)]
[(10.0, 5.656477554152827), (15.0, 5.518753423352734), (20.0, 5.538369232714198), (25.0, 5.523798152568706), (30.0, 5.53725576641077), (35.0, 5.5218183424410014), (40.0, 5.523350461669418), (45.0, 5.531653410599423), (50.0, 5.519886110360921), (55.0, 5.495504075954746), (60.0, 5.483291143318121), (65.0, 5.485041358928483), (70.0, 5.49360138294122), (75.0, 5.4993546868179255), (80.0, 5.495793588413891), (85.0, 5.499689269619098), (90.0, 5.502345293847687), (95.0, 5.499380450456559), (100.0, 5.4860808187812), (105.0, 5.474888395868257), (110.0, 5.469030439040476), (115.0, 5.459149366952276), (120.0, 5.448213297843009), (125.0, 5.433420015075955), (130.0, 5.42028426873691), (135.0, 5.4039370730625), (140.0, 5.389449304230735), (145.0, 5.374739029115512), (150.0, 5.357460575330139), (155.0, 5.340662553581878), (160.0, 5.313241383144196), (165.0, 5.269444679770821), (170.0, 5.238487323826094), (175.0, 5.2086113937648335), (180.0, 5.189242228426556), (185.0, 5.1744945041051), (190.0, 5.159483304652246), (195.0, 5.14430017185943), (200.0, 5.117318556745862), (205.0, 5.10072786906999), (210.0, 5.084061503647151), (215.0, 5.075762136466544), (220.0, 5.068552343275285), (225.0, 5.062863726182678), (230.0, 5.051815330935621), (235.0, 5.031358091612719), (240.0, 5.021260071788471), (245.0, 5.010255285851625), (250.0, 5.003961940532494), (255.0, 4.99636579001612), (260.0, 4.987814326450532), (265.0, 4.980644666607665), (270.0, 4.963432971258708), (275.0, 4.956729825460665), (280.0, 4.948738350016256), (285.0, 4.943941669083361), (290.0, 4.93958132651051), (295.0, 4.933664938830087), (300.0, 4.928992049266768)]

[Ploppz]

A fix for this: Ploppz@8c3670b But it builds on @superfunc's work which has yet to be merged.

[milliams]

This is indeed a bug I've seen creep in in a few situations. Your fix looks sane so I'd invite you to put a PR up for review.

In the future, we'd want to avoid hardcoding the precision and support scientific notation but that can come as a separate feature.