diff options
Diffstat (limited to 'doc')
| -rw-r--r-- | doc/documentation.tex | 19 |
1 files changed, 11 insertions, 8 deletions
diff --git a/doc/documentation.tex b/doc/documentation.tex index 8e35c16..40adc63 100644 --- a/doc/documentation.tex +++ b/doc/documentation.tex @@ -300,17 +300,21 @@ this test to help avoid floating-point rounding problems.) Some interpolators may allow this behavior to be changed by the optional parameter \begin{verbatim} -const CCTK_REAL out_of_range_tolerance[N_dims]; +const CCTK_REAL out_of_range_tolerance[2*N_dims]; \end{verbatim} -The semantics of this are as follows: For each \verb|axis|, +The semantics of this are as follows: + +The array elements are matched up with the axes and minimum/maximum +ends of the grid in the order +$[x_{\min}, x_{\max}, y_{\min}, y_{\max}, z_{\min}, z_{\max}, \dots]$. +An array value \verb|TOL| is interpreted as follows: \begin{description} -\item[\rm If $\hbox{\tt out\_of\_range\_tolerance[axis]} \ge 0.0$,] +\item[\rm If ${\tt TOL} \ge 0.0$,] then an interpolation point is considered to be ``out of range'' if and only if the interpolation point is - $> \verb|out_of_range_tolerance[axis]| - \times \verb|coord_delta[axis]|$ + $> \verb|TOL| \times \verb|coord_delta[axis]|$ outside the grid in this coordinate direction. -\item[\rm If $\hbox{\tt out\_of\_range\_tolerance[axis]} = -1.0$,]%%% +\item[\rm If ${\tt TOL} = -1.0$,]%%% \footnote{%%% Note that this is an {\em exact\/} floating-point equality test! Although such tests are normally @@ -324,8 +328,7 @@ The semantics of this are as follows: For each \verb|axis|, the grid is of infinite extent), would require data from outside the grid. \end{description} -Other values of \verb|out_of_range_tolerance[axis]| are reserved for -future use. +Other values of \verb|TOL| are illegal (reserved for future use). To provide the ``fuzz'' noted above, \verb|out_of_range_tolerance[]| should default to having all elements set to a small positive value, |