===============================================================================
HELP FOR: grmetric
===============================================================================

CALLING SEQUENCE:  grmetric ( mname )

      PARAMETERS:  mname - name of a previously loaded spacetime

-------------------------------------------------------------------------------
SYNOPSIS:

- Sets the default spacetime to that specified by mname.

- The spacetime mname must have been previously initialized using qload(),
  grload() or makeg().

-------------------------------------------------------------------------------
EXAMPLE:

> qload ( schw ):
> qload ( bondi ):
> grdisplay ( g(dn,dn) ):
 
                            For the bondi spacetime:
 
                            Covariant metric tensor
 
                [    0               c(r, v)            0         0       ]
                [                                                         ]
                [                   2 /      m(r, v)\                     ]
                [ c(r, v)  - c(r, v)  |1 - 2 -------|   0         0       ]
                [                     \         r   /                     ]
    g [a] [b] = [                                                         ]
                [                                       2                 ]
                [    0                  0              r          0       ]
                [                                                         ]
                [                                           2           2 ]
                [    0                  0               0  r  sin(theta)  ]
 

> grmetric ( schw ):
Default metric is now schw

> grdisplay ( g(dn,dn) ):

                            For the schw spacetime:
 
                            Covariant metric tensor
 
                       [     1                                      ]
                       [ ---------   0         0             0      ]
                       [ 1 - 2 m/r                                  ]
                       [                                            ]
                       [             2                              ]
           g [a] [b] = [     0      r          0             0      ]
                       [                                            ]
                       [                 2           2              ]
                       [     0       0  r  sin(theta)        0      ]
                       [                                            ]
                       [     0       0         0        - 1 + 2 m/r ]

-------------------------------------------------------------------------------
SEE ALSO: qload, grload, makeg.
===============================================================================