psSpherePrecess()

[gusciora@…]

Please specify an algorithm for this.

[Paul Price]

Section 2.2.3.3 in the ADD, PSDC-430-006-07 (1.2.3.3 in -06).

[gusciora@…]

Does MJD mean "modified julian date"?

Does MJDin corresponds to the fromTime argument, and MJDout correspond to the
toTime argument?

How is the formula in the ADD used to transform one psSphere coordinate to
another? Should I use those those equations to set the valuses of a
psSphereTransfrom structure, then do a sphere transform on it? If so, how
do I set the members of the psSPhereTransform structure?

[gusciora@…]

Also, some of the numbers in the ADD for the Precession section (2.2.3.3) look
to be in degrees. Can I assume they are all in degrees and they all must be
converted to radians before they are used?

[Paul Price]

In the ADD section 2.2.3.3, ALL the coefficients of the polynomials are
specified in degrees (hence the little circles).

[Paul Price]

The three polynomials in 2.2.3.3 specify the three required values to perform a
spherical rotation (i.e., psSphereTransform).

If it helps, please feel free to suggest new names for the elements of
psSphereTransform. I don't have a strong preference as to what goes in there,
since it is an opaque data structure to the user; the intent is to precalculate
the sines and cosines so that rotations may be performed simply and quickly.

[Paul Price]

Closing subsequent to release of SDRS-08, ADD-07.

[Eric.VanAlst@…]

* Bug 237 has been marked as a duplicate of this bug. *

[gusciora@…]

There are three equations in section 2.2.3.3. I'm not sure what to do with
them. I assume that they are used to set the parameters of a spherical
transformation somehow, and that spherical transformation is then applied to the
coords that the function was called with. But I don't know how.

[Paul Price]

I think this is answered in Bug 240. If not, please let me know.