#7 type of TAN-SIP can not be recognized??

[Chao]

The astLib of version 0.3.2 seems not to support wcs type of TAN-SIP.
Example, wcs file is generated by astrometry.net(see attached file), test as following,

• run by astLib.
  t=astLib.astWCS.WCS('Zcapella-A_063.wcs')
  t.pix2wcs(200,300)
  retrun : [77.680657728753062, 46.438810494915934]
• run by wcstools 3.8.0
  xy2sky -d Zcapella-A_063.wcs 200 300
  return: 77.64907 47.66982 J2000 200.000 300.000
  Why there is difference? does astLib not support wcs type of TAN-SIP? or I did something wrong?

[Chao]

wcs file with CTYPE of TNA-SIP

[Matt Hilton]

I think that TAN-SIP etc. are not currently supported by the WCSTools libwcs, which astWCS uses to do the coordinate conversions. However, it looks like this should be fairly straightforward to implement and I will look into adding this over the next couple of weeks.

[Chao]

Seems that the latest version can not recongnize TAN-SIP yet. Could you give me a confirmation? Thanks.