The following is a list and explanation of warning and error messages generated by RAYINVR:

*** error in velocity model *** - an error in the format of the velocity model in the file r.in or v.in has been detected. One of the following problems exists: (1) the x-coordinates of a boundary or upper or lower velocity have not been listed from left to right (2) the x-coordinate of the first or last point of a boundary or upper or lower velocity (comprised of two or more points) does not equal xmin or xmax, respectively (3) a model block has a P-wave velocity less than or equal to zero (4) a line specifying the model (x- or z-coordinates or upper or lower velocity or flags indicating the parameters to be varied during the inversion) in the file r.in or v.in has been omitted (i.e., the file is incomplete) (5) the x-coordinates of the upper layer velocities do not equal the x-coordinates of the lower layer velocities in a layer in which the vertical velocity gradient is to remain fixed during the inversion (6) the x-coordinates of the upper layer boundary do not equal the x-coordinates of the lower layer boundary in a layer in which the thickness is to remain fixed during the inversion *** array size error for number of model points *** - the parameters specifying the maximum number of points defining a layer boundary (ppcntr) and/or the upper or lower layer velocity (ppvel) is not a multiple of 10 *** maximum number of blocks in layer _ exceeded *** - a layer in the velocity model will consist of more than the maximum number of trapezoids allowed for a single layer given the current form of the model. Reduce the number of points defining the upper and/or lower boundary or velocity for the particular layer. *** location of shot point outside model *** - a shot point is located outside the model. *** error in specification of amin or amax *** - values of amin or amax have not been specified or are greater than 180 in absolute value. *** max reflecting boundaries exceeded *** - the number of reflecting boundaries in nrbnd is greater than that allowed for one or more ray groups. *** max converting boundaries exceeded *** - the number of converting boundaries in ncbnd is greater than that allowed for one or more ray groups. *** reflect boundary greater than # of layers *** - a boundary in rbnd is greater than or equal to the number of model layers. *** no ray codes specified *** - no ray codes have been specified in the array ray. *** shot# _ ray code _ no rays traced *** - the search mode was unable to find rays for the shot point and ray code specified. *** shot# _ ray code _ 1 ray traced *** - the search mode was unable to find the maximum take-off angle of a refracted ray group for the shot point and ray code specified; only a single ray with a take-off angle equal to the minimum value is traced. *** less than nray rays traced for _ ray groups *** - the search mode was unable to find rays (or traced less than nray rays) for the number of ray groups specified. *** possible inaccuracies in rngkta *** - the Runge Kutta routine has detected possible inaccuracies in its attempt to solve the ray tracing equations. The exact point(s) at which the problem occurred can be found in the file r2.out if idump=1 is used. The problem can be eliminated by either reducing the velocity gradient in the appropriate location of the model or reducing the value of step and/or smin. Note that this warning is conservative so that no significant inaccuracies may have occurred. *** ray stopped - consists of too many points *** - a ray is composed of more than the maximum number of points (step lengths) allowed. Tracing of this ray is terminated. *** ray stopped - illegal reflection *** - a ray has reflected off a boundary not specified in ray or rbnd and istop=1. Tracing of this ray is terminated. *** ray stopped - converted ray cannot reflect/refract *** - a ray is at a point of conversion from S to P and is beyond the critical angle. Tracing of this ray is terminated. *** ray stopped - s-wave cannot propagate *** - a ray propagating as an S-wave has entered a model block in which the S-wave velocity is zero. Tracing of this ray is terminated. *** ray stopped - reflected from pinchout *** - the layer from which a ray is to be reflected has zero thickness. Tracing of this ray is terminated. *** block undetermined *** - this is the most serious error since it implies that RAYINVR has lost track of what model block a ray is supposed to be in and therefore implies there is probably a bug in the code. The problem may be avoided if the ray step length is reduced. Also check that layer boundaries do not cross or a deeper boundary is specified before a shallower boundary in the file r.in or v.in. Also check that a source is not located exactly on a layer or block boundary or the edge of the model. *** max number of rays reaching surface exceeded *** - the maximum allowable number of rays reaching the surface (not including those traced in the search mode) has been reached. *** no parameters varied for inversion *** - invr=1 but no model parameters have been selected for inversion in the file r.in or v.in. *** too many parameters varied for inversion *** - the maximum allowable number of model parameters selected for inversion has been exceeded. *** attempt to interpolate over ximax *** - invr=1 and the travel time and partial derivatives were to be interpolated to an observed receiver location using two rays that have end points greater than ximax from the receiver location; no interpolation is performed. This message is included in the file r1.out at the end of each ray group in which this occurs at least once.

Sat Mar 7 19:13:54 EST 1998