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.