Healpy map2alm and alm2map errors
<p>I'm studying healpy. Specifically I am interested in map2alm and alm2map: I found  <a href="https://stackoverflow.com/questions/25980039/healpy-map2alm-and-alm2map-inconsistency">question</a> where example of applying the functions "to both sides" (in answer) is provided. As we can see, we get significant errors in comparison with the original map after applying map2alm and alm2map consecutively.Therefore I want to control these errors. So my question is:  </p>

<ol>
<li>Is there any way to reduce the error, without using higher nside? (For example if I want to use a certain nside) </li>
<li>Also, maybe there is another way to get a "spectral characteristic" of a map, that wouldn't have such big errors?</li>
</ol>