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Diffstat (limited to 'doc/documentation.tex')
| -rw-r--r-- | doc/documentation.tex | 71 |
1 files changed, 37 insertions, 34 deletions
diff --git a/doc/documentation.tex b/doc/documentation.tex index 73b24c6..6f74bdf 100644 --- a/doc/documentation.tex +++ b/doc/documentation.tex @@ -25,8 +25,8 @@ Base thorn to provide the variables for the static conformal factor This thorn provides the variables defining a static conformal factor which is used to transform the physical metric. If this thorn is -active and the {\tt ADMBase::metric\_type} parameter is set to -``{\tt static conformal}'' then the {\tt ADMBase::g...} variables are the +active and the {\tt ADMBase::metric\_type} parameter is set to {\tt +static conformal}, then the {\tt ADMBase::g...} variables are the conformal values as opposed to the physical values. The transformation is @@ -58,7 +58,8 @@ actually been calculated before using the conformal factor: \begin{description} \item[{\tt conformal\_state=0}] No conformal factor has been calculated --- thorns may -assume the conformal factor is 1 at all points. (I.e., the metric is physical.) +assume the conformal factor is 1 at all points. +(I.e., the metric is physical.) \item[{\tt conformal\_state=1}] The conformal factor has been calulated, but no derivatives. \item[{\tt conformal\_state=2}] @@ -68,14 +69,21 @@ The conformal factor and its first and second derivatives have been calculated. \end{description} Note that this means that if you only want to know whether {\tt psi} contains -the values for the conformal factor you can check for {\tt conformal\_state > 0}. +the values for the conformal factor you can check for {\tt +conformal\_state > 0}. \section{Utilities} -{\tt StaticConformal} provides functions to convert between physical and conformal 3-metric values. It is very important to understand that these functions -apply the conversion {\it in place}. That is, if {\tt gxx} contains the conformal metric value, when the routine is exited it will now contain the physical metric value. These functions {\it do not} change the value of {\tt conformal\_state} and should be used with due care. (These functions are for example used -by some analysis thorns who work only with the physical metric, they apply the -transformation on entry to the analysis routine and switch it back on exit). +{\tt StaticConformal} provides aliased functions to convert between +physical and conformal 3-metric values. It is very important to +understand that these functions apply the conversion {\em in place}. +That is, if {\tt gxx} contains the conformal metric value, when the +routine is exited it will now contain the physical metric value. +These functions {\em do not} change the value of {\tt +conformal\_state} and should be used with due care. (These functions +are for example used by some analysis thorns who work only with the +physical metric, they apply the transformation on entry to the +analysis routine and switch it back on exit). \begin{description} @@ -84,17 +92,14 @@ transformation on entry to the analysis routine and switch it back on exit). {\tt \begin{verbatim} - -StaticConf_ConfToPhysInPlace (cctk_lsh(1), - cctk_lsh(2), - cctk_lsh(3), +subroutine ConfToPhysInPlace (nx, ny, nz, psi, - gxx, - gxy, - gxz, - gyy, - gyz, - gzz) + gxx, gxy, gxz, gyy, gyz, gzz) + implicit none + CCTK_INT, intent(in) :: nx, ny, nz + CCTK_REAL, dimension(nx, ny, nz), intent(in) :: psi + CCTK_REAL, dimension(nx, ny, nz), intent(inout) :: gxx, gxy, gxz, gyy, gyz, gzz +end subroutine ConfToPhysInPlace \end{verbatim} } @@ -103,17 +108,14 @@ StaticConf_ConfToPhysInPlace (cctk_lsh(1), {\tt \begin{verbatim} - -StaticConf_PhysToConfInPlace (cctk_lsh(1), - cctk_lsh(2), - cctk_lsh(3), +subroutine PhysToConfInPlace (nx, ny, nz, psi, - gxx, - gxy, - gxz, - gyy, - gyz, - gzz) + gxx, gxy, gxz, gyy, gyz, gzz) + implicit none + CCTK_INT, intent(in) :: nx, ny, nz + CCTK_REAL, dimension(nx, ny, nz), intent(in) :: psi + CCTK_REAL, dimension(nx, ny, nz), intent(inout) :: gxx, gxy, gxz, gyy, gyz, gzz +end subroutine ConfToPhysInPlace \end{verbatim} } @@ -127,14 +129,15 @@ factor, but does initialise the {\tt conformal\_state} variable to 0. Please note, no thorn should use the {\tt conformal\_state} variable unless the parameter {\tt metric\_type} is {\tt "static conformal"}. The {\tt conformal\_state} variable is not assigned storage or -initialised by the \texttt{StaticConformal} thorn in any other case. +initialised by the {\tt StaticConformal} thorn in any other case. However, thorns are free to themselves assign storage for {\tt conformal\_state} and initialise it to zero if {\tt metric\_type} is -``physical''. In this one case it is safe for them to use the -\texttt{conformal\_state} variable if \texttt{metric\_type} is not -``static conformal''. This method allows them to use just one set of -ifs rather than first checking the metric\_type and then the -conformal\_state variable if the metric\_type is ``static conformal''. +{\tt physical}. In this one case it is safe for them to use the {\tt +conformal\_state} variable if {\tt metric\_type} is not {\tt static +conformal}. This method allows them to use just one set of ifs rather +than first checking the {\tt metric\_type} and then the {\tt +conformal\_state} variable if the {\tt metric\_type} is {\tt static +conformal}. % Do not delete next line % END CACTUS THORNGUIDE |