Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Error Analysis regarding the calculation of NLFF Field   Field extrapolation is an alternative method to study chromospheric and
coronal magnetic fields. In this paper, two semi-analytical solutions of force-
free fields (Low and Lou, 1990) have been used to study the errors of nonlin-
ear force-free (NLFF) fields based on force-free factor alpha. Three NLFF
fields are extrapolated by approximate vertical integration (AVI) Song et al.
(2006), boundary integral equation (BIE) Yan and Sakurai (2000) and
optimization (Opt.) Wiegelmann (2004) methods. Compared with the first
semi-analytical field, it is found that the mean values of absolute relative
standard deviations (RSD) of alpha along field lines are about 0.96-1.05,
0.94-1.07 and 0.46-0.72 for AVI, BIE and Opt. fields, respectively. While for
the second semi-analytical field, they are about 0.80-1.02, 0.63-1.34 and
0.33-0.55 for AVI, BIE and Opt. fields, respectively. As for the analytical
field, the calculation error of hjRSDji is about 0.1 {\guillemotright} 0.2. It
is also found that RSD does not apparently depend on the length of field line.
These provide the basic estimation on the deviation of extrapolated field
obtained by proposed methods from the real force-free field.

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The categories of this paper are: physics
30
The categories of this paper are: q-alg
34
The categories of this paper are: chem-ph
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The categories of this paper are: cond-mat
28
The categories of this paper are: alg-geom
37
The categories of this paper are: supr-con
31
The categories of this paper are: ao-sci
14
The categories of this paper are: math-ph
7
The categories of this paper are: hep-th
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The categories of this paper are: dg-ga
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The categories of this paper are: q-fin
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The categories of this paper are: math
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The categories of this paper are: cmp-lg
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The categories of this paper are: stat
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The categories of this paper are: nlin
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The categories of this paper are: cs