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Python-based Hierarchical ENvironment for Integrated Xtallography
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phenix.map_value_at_point: tool to compute map value at a given point using eight-point interpolation.

Inputs:
  • MTZ file containing Fourier map coefficients;
  • label selecting which map coefficients should be used (in case there are multiple choices in input file, there is no need to provide label otherwise);
  • the coordinates of points at which the map value will be computed can be defined in two ways: either providing a triplet of xyz coordinates using 'point' keyword, or giving a PDB file in the command line in which case the atomic coordinates will serve as points;
  • optionally the 'resolution_factor' can be specified. It defines the map calculation grid step as grid_step=resolution_factor*d_min
  • optionally, type of map scaling can be defined: sigma or volume scaled (sigma is the default).
Usage examples:
  1. phenix.map_value_at_point map_coeffs.mtz point="0.5 1.2 3" point="0.53 3.3 2.5" label="2mFo-DFc"
  2. phenix.map_value_at_point map_coeffs.mtz model.pdb
  3. phenix.map_value_at_point map_coeffs.mtz model.pdb point="1 2 3" resolution_factor=0.3

IMPORTANT: point must be a triplet of Cartesian coordinates (not fractional)!

Output:
list of map values at specified points.
Default params:
label = None
point = None
resolution_factor = 0.25
scale = *sigma volume