Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: A comparison between Fast Multipole Algorithm and Tree-Code to evaluate
  gravitational forces in 3-D   We present tests of comparison between our versions of the Fast Multipole
Algorithm (FMA) and ``classic'' tree-code to evaluate gravitational forces in
particle systems. We have optimized the Greengard's original version of FMA
allowing for a more efficient criterion of well-separation between boxes, to
improve the adaptivity of the method (which is very important in highly
inhomogeneous situations) and to permit the smoothing of gravitational
interactions. The results of our tests indicate that the tree-code is almost
three times faster than FMA for both a homogeneous and a clumped distribution,
at least in the interval of N (N< 10^5) here investigated and at the same level
of accuracy (error ~ 10^{-3)). This order of accuracy is generally considered
as the best compromise between CPU-time consumption and precision for
astrophysical simulation. Moreover, the claimed linear dependence on N of the
CPU-time of FMA is not confirmed and we give a ``theoretical'' explanation for
that.

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The categories of this paper are: chao-dyn
17
The categories of this paper are: q-fin
28
The categories of this paper are: alg-geom
31
The categories of this paper are: ao-sci
32
The categories of this paper are: atom-ph
12
The categories of this paper are: nucl-th
33
The categories of this paper are: plasm-ph
2
The categories of this paper are: math
13
The categories of this paper are: quant-ph
21
The categories of this paper are: adap-org
20
The categories of this paper are: acc-phys
4
The categories of this paper are: cond-mat
34
The categories of this paper are: chem-ph
10
The categories of this paper are: q-bio
15
The categories of this paper are: nucl-ex
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The categories of this paper are: stat