Is there any mapping function between low resolution and high resolution?

[GoogleCodeExporter]

Thank you for healpy builder. 

By the way, I have a question in WMAP operation by using healpy. As far as I 
know, 12*4^n is the number of pixels in the healpix data structure. In this 
case, suppose that we have two different resolutioned map: 1) a 12*4^n
size map and 2) a 12*4^k size map where n>>k.

Thus, there are 4^(n-k) pixels of the large size map which indicate or project 
a specific pixel of the small size map.

My question is whether healpy has any functional projection rule or any 
function of healpix to make the following task:

Indeces4B = getIndeces(A, B, index4A); or
Indeces4B = getIndeces(n, k, index4A); or
Indeces4B = getIndeces(12*4^n, 12*4^k, index4A);

where A and B are small map (low resolution=k) and a large map (high
resolution=n) respectively. index4A can be an index to a specific pixel of the 
small map. Indeces4B is the a corresponding set of indeces of the large size 
map to the specific pixel index of the small map.

Basically, I need the above function but I could not find it properly. If it is 
required to be built by myself, do you know what is the equation for it or 
where I can find it?

Thanks.

What version of the product are you using? On what operating system?
I am using the latest python on ubuntu.

Original issue reported on code.google.com by this.is....@gmail.com on 12 Aug 2010 at 1:34

[GoogleCodeExporter]

You can look at the function healpy.ud_grade and at its code.
(it is a direct translation of the IDL routine from the original healpix 
package).

Original comment by cyrille....@gmail.com on 31 Aug 2010 at 12:51

[GoogleCodeExporter]

Original comment by andrea.z...@gmail.com on 12 Oct 2010 at 12:47

• Changed state: Done