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HELP FOR: grload
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CALLING SEQUENCE:  grload ( metricName, pathString )

      PARAMETERS:  metricName - name to be assigned to the metric for the
                                current session
                   pathString - path to the file containing the metric

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SYNOPSIS:

- Reads the metric contained in the file indicated by pathString and
  assigns it the name metricName.

- The metric which is loaded becomes the default metric for subsequent
  calculations.

- The parameter pathString is a MapleV string (i.e. enclosed
  in backquotes). Directories in the path are separated by forward
  slashes (even under MS-DOS/Windows).

- Metric files can be created using the command makeg(). A directory of
  commonly used metrics is included with the GRTensorII distribution. An
  online collection is kept at http://astro.queensu.ca/~grtensor/.

- Older metric files do not have an entry specifying the spacetime
  signature. If the global grOptionLLSC variable is set true, then
  the following assumptions are made: if the spacetime is specified
  by a four dimensional metric or general basis, then the signature
  is set to +2; if the spacetime is specified by a set of basis vectors
  satisfying an NP inner product, then the signature is set to -2.
  These assumptions are overridden if the signature is explicitly
  contained in the metric file. If the grOptionLLSC variable is set
  false, then the signature is left unnassigned unless the signature
  is explicitly given by the metric file. See ?groptions for a
  description of the grOptionLLSC variable. To see the signature
  of the current spacetime, use grdisplay(sig).

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EXAMPLES:

> grload ( schw, `c:/metrics/schw.mpl` );

Calculated ds for schw. (0.010000 sec.) 
                            Default spacetime = schw
 
                            For the schw spacetime:
 
                                  Coordinates
 
                             a
                           x   = [ r, theta, phi, t ]
 
                                  Line element
 
    2
  ds  =
 
           2
        d r       2         2     2           2       2                      2
     --------- + r   d theta   + r  sin(theta)   d phi   + (- 1 + 2 m/r)  d t
     1 - 2 m/r
 
                       The Classical Schwarzschild metric
 
> grcalc ( R(dn,dn) ):

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SEE ALSO: qload(), makeg().
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