saxsdata.ini_saxs() -- Initialization of SAXS data

s_min = <float:1>		minimum frequency in reciprocal space in Å$^{-1}$ - default = 0.0
s_max = <float:1>		maximum frequency in reciprocal space in Å$^{-1}$ - default = 2.0
maxs = <int:1>		maximum number of frequencies - default = 100
nmesh = <int:1>		actual number of frequencies (<= maxs) - default = 100
natomtyp = <int:1>		number of ''atoms'', i.e. scattering centers - default = 15
represtyp = <str:1>		representation : 'heav', 'allh', or 'CA' - default='heav'
filename = <str:1>		filename of the library for formfactors
wswitch = <str:1>		character for filter of scoring function options 'unity' (default), 'sq', or 'hybrid'
s_hybrid = <float:1>		frequency above which $s^2$ weighting is applied if 'hybrid' - default=0.0
s_low = <float:1>		bandpass filter in Å$^{-1}$ - lower cutoff - default=0.0
s_hi = <float:1>		bandpass filter in Å$^{-1}$ - higher cutoff - default = 2.0
spaceflag = <str:1>		how should $I(s)$ be computed? 'real' space via $P(r)$ or 'reciprocal'? 'real' is more than a magnitude faster but less accurate for high resolution ($s>0.5$ ) - default='real'
rho_solv = <float:1>		electron density of solvent - default=0.334 $e^-$ Å$^{-3}$ (H$_2$ O)
use_lookup = <bool:1>		use lookup tables for SINC and COS function - significant increase in speed for 'reciprocal' mode - default=True
nr = <int:1>		number of points for $P(r)$ sampling - default= 5000
dr = <float:1>		spacing (sampling) of $P(r)$ in Å- default=0.1
use_offset = <bool:1>		allow for additive constant in expt. spectrum - default=False

Routine to initialize the SAXSDATA structure. Here the sampling in reciprocal space needs to be specified; currently only equidistant sampling is possible. Moreover, the parameters for the scoring function and for its computation are set.