invr - calculate partial derivatives of the selected model parameters and write these to the file i.out (default: 0)

ivray - an array of non-zero integers corresponding to the ray groups listed in the array ray used to identify the type of arrival in the file tx.out if itxout=2 or 3 and to allow for the appropriate comparison with the observed travel times in the file tx.in if invr=1 or i2pt>0 ximax - the maximum allowable distance (km) between the nearest ray end point and an observed seismogram location for one of the rays used to interpolate the partial derivatives and travel time at that observed seismogram location (default: (xmax-xmin)/20) ttunc - uncertainty of the calculated travel times (s) written to the file tx.out if itxout>0 (default: 0.01) bndunc, velunc - estimated uncertainty of the depth of boundary nodes (km) and velocities (km/s) written to the file i.out (defaults: 0.1, 0.1)

Sat Mar 7 19:13:54 EST 1998