= volume =
 ''This program calculates the volume/mass of a 3D map''

== Usage ==
 volume  <input file> <A/pix> [thr=<thresh>] [calc=<mass>] [set=<mass>] [plot]

=== Parameters ===
 || <input file>||3D map to work with||
 || <A/pix>||Angstroms/voxel in the map||
 ||[thr=<thresh>]||Calculate the volume/mass at a given threshold||
 ||[calc=<mass>]||Determine the threshold for a given mass||
 ||[set=<mass>]||Rescale the map densities so a threshold of 1 gives the specified mass||
 ||[plot]||Output a x/y file containing a plot of threshold vs mass||
 Typical usage: volume threed.1a.mrc 4.667 set=2500

== Description ==
This routine calculates volumes enclosed by isosurfaces. The algorithm used is approximate. It doesn't calculate subvoxel volumes. It is fairly accurate as  long as a substantial fraction of the voxels are 'inside' the volume.

For convenience, mass is specified rather than volume. Volume/mass conversions assume a density of 1.35 g/ml (0.81 Da/A^3^).

Please note that an earlier version of the docs cited 1.35 Da/A^3^. This  was an error in the documentation only. The program was using the correct value.

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EMAN Manual page, generated Mon Jan  8 17:35:59 2007