DATMW manual

datmw

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DATMW

DATMW estimates molecular weight (MW) from SAXS data using several complementary methods.

Running datmw

Usage:

$ datmw [OPTIONS] [FILE(S)]

One or more SAXS data files may be supplied. By default, DATMW uses the Bayesian method.

Methods

Method	Description	Output
`Porod`	MW from Porod volume (Petoukhov et al., 2012)	s_max (Å^-1), volume (Å³), MW (Da), file name
`Qp`	MW from the Porod invariant (Hajizadeh et al., 2018)	s_max (Å^-1), MW (Da), file name
`Vc`	MW from the volume of correlation (Rambo and Tainer, 2013)	s_max (Å^-1), V_c, MW (Da), file name
`MoW`	MW from apparent volume (Fischer et al., 2010)	s_max (Å^-1), Q', V', volume (Å³), MW (Da), file name
`sizeshape`	MW from size and shape (Franke et al., 2018)	MW (Da), file name
`Bayes`	MW from Bayesian inference (Hajizadeh et al., 2018)	MW (Da), MW score, CI lower, CI upper, CI probability, file name
`absolute`	MW from data on an absolute scale (Mylonas and Svergun, 2007)	MW (Da), file name
`relative`	MW from a relative scale and a standard (Mylonas and Svergun, 2007)	MW (Da), file name

--i0 is required for all methods. --rg and --first are required for Porod, Qp, Vc, MoW, sizeshape and Bayes. For absolute, partial specific volume and contrast are optional, but the data must be on an absolute scale. For relative, --i0_standard and --mw_standard are required.

Command-line arguments and options

Short option	Long option	Description
	`--i0=<VALUE>`	Experimental forward scattering I(0).
	`--rg=<VALUE>`	Experimental radius of gyration.
	`--first=<N>`	Index of the first point to be used (default: 1).
	`--psv=<X>`	Partial specific volume in cm³/g (default: 0.7425).
	`--contrast=<X>`	Contrast in units of 10¹⁰ cm^-2 (default: 2.8086).
	`--i0_standard=<VALUE>`	Experimental forward scattering of the standard.
	`--mw_standard=<VALUE>`	Expected molecular weight of the standard.
	`--method=<NAME>`	One of `Porod`, `Qp`, `Vc`, `MoW`, `sizeshape`, `Bayes`, `absolute` or `relative` (default: `Bayes`).
`-v`	`--version`	Print version information and exit.
`-h`	`--help`	Print usage information and exit.

Input files

Each FILE is a SAXS data file. The parameters required in addition to the file depend on the selected method.

Output

DATMW writes one result for each input file. The reported columns depend on the selected method, as listed above.

Examples

$ datmw --i0=<VALUE> --rg=<VALUE> sample.dat
$ datmw --method=absolute --i0=<VALUE> sample_absolute.dat
$ datmw --method=relative --i0=<VALUE> --i0_standard=<VALUE> --mw_standard=<VALUE> sample.dat