The Spatial Extent of the Data

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The Spatial Extent of the Data

The spatial characteristics of a data group are printed to the Console Window when the bound command is used. If we open the Complex Data and type the command

bound

Partiview will report several lines of information about the data group. The format of the report is:

num specks in range xmin ymin zmin .. xmax ymax zmax
midbbox xcen ycen zcen boxradius xrad yrad zrad
mean xavg yavg zavg
where num is the number of data points, xmin, xmax are the minimum and maximum points in the x direction, xcen ycen zcen is the center of the data distribution, xrad yrad zrad are the half-lengths of the data distribution, and xavg yavg zavg are the averages for each coordinate.

Appended to the end of each line of the report is the coordinate system to which these numbers are relevant. Without an argument, bound reports the 3-D extent of the data in object coordinates, the coordinate system defined by the data itself. So, for the Complex Data, we see that the particles range from -1 to +1 in each coordinate with the center and mean at (0, 0, 0). If the command

bound w
is run, then the report is in terms of the world coordinate system. This produces the same report in the Complex Data, however, if we transform these data using the tfm command
tfm 4 4 0 0 0 0
then rerun bound, you will see that the report reflects the data values, not the transformed data. Running the bound w command accounts for this transformation in its report on the particles.

© 2002-2005 American Museum of Natural History
Last Modified: 2006-04-28 by Brian Abbott