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revision 1.4 by heimbach, Fri Oct 5 22:22:20 2001 UTC revision 1.7 by cnh, Thu Oct 25 18:36:55 2001 UTC
# Line 21  The MITGCM has been adapted for use with Line 21  The MITGCM has been adapted for use with
21  Tangent linear and Adjoint Model Compiler (TAMC) and its successor TAF  Tangent linear and Adjoint Model Compiler (TAMC) and its successor TAF
22  (Transformation of Algorithms in Fortran), developed  (Transformation of Algorithms in Fortran), developed
23  by Ralf Giering (\cite{gie-kam:98}, \cite{gie:99,gie:00}).  by Ralf Giering (\cite{gie-kam:98}, \cite{gie:99,gie:00}).
24  The first application of the adjoint of the MITGCM for senistivity  The first application of the adjoint of the MITGCM for sensitivity
25  studies has been published by \cite{maro-eta:99}.  studies has been published by \cite{maro-eta:99}.
26  \cite{sta-eta:97,sta-eta:01} use the MITGCM and its adjoint  \cite{sta-eta:97,sta-eta:01} use the MITGCM and its adjoint
27  for ocean state estimation studies.  for ocean state estimation studies.
# Line 52  $\vec{u}=(u_1,\ldots,u_m)$ Line 52  $\vec{u}=(u_1,\ldots,u_m)$
52  such as forcing functions) to the $n$-dimensional space  such as forcing functions) to the $n$-dimensional space
53  $V \subset I\!\!R^n$ of  $V \subset I\!\!R^n$ of
54  model output variable $\vec{v}=(v_1,\ldots,v_n)$  model output variable $\vec{v}=(v_1,\ldots,v_n)$
55  (model state, model diagnostcs, objective function, ...)  (model state, model diagnostics, objective function, ...)
56  under consideration,  under consideration,
57  %  %
58  \begin{equation}  \begin{equation}
# Line 220  model integration, Line 220  model integration,
220  starting at step 0 and moving up to step $\Lambda$, with intermediate  starting at step 0 and moving up to step $\Lambda$, with intermediate
221  ${\cal M}_{\lambda} (\vec{u}) = \vec{v}^{(\lambda+1)}$ and final  ${\cal M}_{\lambda} (\vec{u}) = \vec{v}^{(\lambda+1)}$ and final
222  ${\cal M}_{\Lambda} (\vec{u}) = \vec{v}^{(\Lambda+1)} = \vec{v}$.  ${\cal M}_{\Lambda} (\vec{u}) = \vec{v}^{(\Lambda+1)} = \vec{v}$.
223  Let ${\cal J}$ be a cost funciton which explicitly depends on the  Let ${\cal J}$ be a cost function which explicitly depends on the
224  final state $\vec{v}$ only  final state $\vec{v}$ only
225  (this restriction is for clarity reasons only).  (this restriction is for clarity reasons only).
226  %  %
# Line 301  We note in passing that that the $\delta Line 301  We note in passing that that the $\delta
301  are the Lagrange multipliers of the model equations which determine  are the Lagrange multipliers of the model equations which determine
302  $ \vec{v}^{(\lambda)}$.  $ \vec{v}^{(\lambda)}$.
303    
304  In coponents, eq. (\ref{adjoint}) reads as follows.  In components, eq. (\ref{adjoint}) reads as follows.
305  Let  Let
306  \[  \[
307  \begin{array}{rclcrcl}  \begin{array}{rclcrcl}
# Line 322  Let Line 322  Let
322  \end{array}  \end{array}
323  \]  \]
324  denote the perturbations in $\vec{u}$ and $\vec{v}$, respectively,  denote the perturbations in $\vec{u}$ and $\vec{v}$, respectively,
325  and their adjoint varaiables;  and their adjoint variables;
326  further  further
327  \[  \[
328  M \, = \, \left(  M \, = \, \left(
# Line 468  variables $u$ Line 468  variables $u$
468  {\it all} intermediate states $ \vec{v}^{(\lambda)} $) are sought.  {\it all} intermediate states $ \vec{v}^{(\lambda)} $) are sought.
469  In order to be able to solve for each component of the gradient  In order to be able to solve for each component of the gradient
470  $ \partial {\cal J} / \partial u_{i} $ in (\ref{forward})  $ \partial {\cal J} / \partial u_{i} $ in (\ref{forward})
471  a forward calulation has to be performed for each component seperately,  a forward calculation has to be performed for each component separately,
472  i.e. $ \delta \vec{u} = \delta u_{i} {\vec{e}_{i}} $  i.e. $ \delta \vec{u} = \delta u_{i} {\vec{e}_{i}} $
473  for  the $i$-th forward calculation.  for  the $i$-th forward calculation.
474  Then, (\ref{forward}) represents the  Then, (\ref{forward}) represents the
# Line 487  M^T \left( \nabla_v {\cal J}^T \left(\de Line 487  M^T \left( \nabla_v {\cal J}^T \left(\de
487  \nabla_u {\cal J}^T \cdot \delta \vec{J}  \nabla_u {\cal J}^T \cdot \delta \vec{J}
488  \]  \]
489  where now $ \delta \vec{J} \in I\!\!R^l $ is a vector of  where now $ \delta \vec{J} \in I\!\!R^l $ is a vector of
490  dimenison $ l $.  dimension $ l $.
491  In this case $ l $ reverse simulations have to be performed  In this case $ l $ reverse simulations have to be performed
492  for each $ \delta J_{k}, \,\, k = 1, \ldots, l $.  for each $ \delta J_{k}, \,\, k = 1, \ldots, l $.
493  Then, the reverse mode is more efficient as long as  Then, the reverse mode is more efficient as long as
494  $ l < n $, otherwise the forward mode is preferable.  $ l < n $, otherwise the forward mode is preferable.
495  Stricly, the reverse mode is called adjoint mode only for  Strictly, the reverse mode is called adjoint mode only for
496  $ l = 1 $.  $ l = 1 $.
497    
498  A detailed analysis of the underlying numerical operations  A detailed analysis of the underlying numerical operations
# Line 570  point of evaluation has to be recomputed Line 570  point of evaluation has to be recomputed
570  A method to balance the amount of recomputations vs.  A method to balance the amount of recomputations vs.
571  storage requirements is called {\sf checkpointing}  storage requirements is called {\sf checkpointing}
572  (e.g. \cite{res-eta:98}).  (e.g. \cite{res-eta:98}).
573  It is depicted in \reffig{3levelcheck} for a 3-level checkpointing  It is depicted in \ref{fig:3levelcheck} for a 3-level checkpointing
574  [as an example, we give explicit numbers for a 3-day  [as an example, we give explicit numbers for a 3-day
575  integration with a 1-hourly timestep in square brackets].  integration with a 1-hourly timestep in square brackets].
576  \begin{itemize}  \begin{itemize}
# Line 607  at every timestep Line 607  at every timestep
607  [i.e. every hour $ i=0,...,5$ corresponding to  [i.e. every hour $ i=0,...,5$ corresponding to
608  $ k_{i}^{lev1} = 66, 67, \ldots, 71 $].  $ k_{i}^{lev1} = 66, 67, \ldots, 71 $].
609  Thus, the  final state $ v_n = v_{k_{n}^{lev1}} $ is reached  Thus, the  final state $ v_n = v_{k_{n}^{lev1}} $ is reached
610  and the model state of all peceeding timesteps along the last  and the model state of all  proceeding timesteps along the last
611  sub-subsections are available, enabling integration backwards  sub-subsections are available, enabling integration backwards
612  in time along the last sub-subsection.  in time along the last sub-subsection.
613  Thus, the adjoint can be computed along this last  Thus, the adjoint can be computed along this last
# Line 637  The balance of storage vs. recomputation Line 637  The balance of storage vs. recomputation
637  on the computing resources available.  on the computing resources available.
638    
639  \begin{figure}[t!]  \begin{figure}[t!]
640  \centering  \begin{center}
641  %\psdraft  %\psdraft
642  \psfrag{v_k1^lev3}{\mathinfigure{v_{k_{1}^{lev3}}}}  %\psfrag{v_k1^lev3}{\mathinfigure{v_{k_{1}^{lev3}}}}
643  \psfrag{v_kn-1^lev3}{\mathinfigure{v_{k_{n-1}^{lev3}}}}  %\psfrag{v_kn-1^lev3}{\mathinfigure{v_{k_{n-1}^{lev3}}}}
644  \psfrag{v_kn^lev3}{\mathinfigure{v_{k_{n}^{lev3}}}}  %\psfrag{v_kn^lev3}{\mathinfigure{v_{k_{n}^{lev3}}}}
645  \psfrag{v_k1^lev2}{\mathinfigure{v_{k_{1}^{lev2}}}}  %\psfrag{v_k1^lev2}{\mathinfigure{v_{k_{1}^{lev2}}}}
646  \psfrag{v_kn-1^lev2}{\mathinfigure{v_{k_{n-1}^{lev2}}}}  %\psfrag{v_kn-1^lev2}{\mathinfigure{v_{k_{n-1}^{lev2}}}}
647  \psfrag{v_kn^lev2}{\mathinfigure{v_{k_{n}^{lev2}}}}  %\psfrag{v_kn^lev2}{\mathinfigure{v_{k_{n}^{lev2}}}}
648  \psfrag{v_k1^lev1}{\mathinfigure{v_{k_{1}^{lev1}}}}  %\psfrag{v_k1^lev1}{\mathinfigure{v_{k_{1}^{lev1}}}}
649  \psfrag{v_kn^lev1}{\mathinfigure{v_{k_{n}^{lev1}}}}  %\psfrag{v_kn^lev1}{\mathinfigure{v_{k_{n}^{lev1}}}}
650  \mbox{\epsfig{file=part5/checkpointing.eps, width=0.8\textwidth}}  %\mbox{\epsfig{file=part5/checkpointing.eps, width=0.8\textwidth}}
651    \resizebox{5.5in}{!}{\includegraphics{part5/checkpointing.eps}}
652  %\psfull  %\psfull
653  \caption  \end{center}
654  {Schematic view of intermediate dump and restart for  \caption{
655    Schematic view of intermediate dump and restart for
656  3-level checkpointing.}  3-level checkpointing.}
657  \label{fig:3levelcheck}  \label{fig:3levelcheck}
658  \end{figure}  \end{figure}
# Line 677  generate a tangent linear or adjoint mod Line 679  generate a tangent linear or adjoint mod
679  We take as an example the sensitivity of carbon sequestration  We take as an example the sensitivity of carbon sequestration
680  in the ocean.  in the ocean.
681  The AD-relevant hooks in the code are sketched in  The AD-relevant hooks in the code are sketched in
682  \reffig{adthemodel}, \reffig{adthemain}.  \ref{fig:adthemodel}, \ref{fig:adthemain}.
683    
684  \subsection{Overview of the experiment}  \subsection{Overview of the experiment}
685    
686  We describe an adjoint sensitivity analysis of outgassing from  We describe an adjoint sensitivity analysis of out-gassing from
687  the ocean into the atmosphere of a carbon-like tracer injected  the ocean into the atmosphere of a carbon-like tracer injected
688  into the ocean interior (see \cite{hil-eta:01}).  into the ocean interior (see \cite{hil-eta:01}).
689    
# Line 689  into the ocean interior (see \cite{hil-e Line 691  into the ocean interior (see \cite{hil-e
691    
692  For this work the MITGCM was augmented with a thermodynamically  For this work the MITGCM was augmented with a thermodynamically
693  inactive tracer, $C$. Tracer residing in the ocean  inactive tracer, $C$. Tracer residing in the ocean
694  model surface layer is outgassed according to a relaxation time scale,  model surface layer is out-gassed according to a relaxation time scale,
695  $\mu$. Within the ocean interior, the tracer is passively advected  $\mu$. Within the ocean interior, the tracer is passively advected
696  by the ocean model currents. The full equation for the time evolution  by the ocean model currents. The full equation for the time evolution
697  %  %
# Line 709  parameterized according to Gent/McWillia Line 711  parameterized according to Gent/McWillia
711  The convection function, $\Gamma$, mixes $C$ vertically wherever the  The convection function, $\Gamma$, mixes $C$ vertically wherever the
712  fluid is locally statically unstable.  fluid is locally statically unstable.
713    
714  The outgassing time scale, $\mu$, in eqn. (\ref{carbon_ddt})  The out-gassing time scale, $\mu$, in eqn. (\ref{carbon_ddt})
715  is set so that \( 1/\mu \sim 1 \ \mathrm{year} \) for the surface  is set so that \( 1/\mu \sim 1 \ \mathrm{year} \) for the surface
716  ocean and $\mu=0$ elsewhere. With this value, eqn. (\ref{carbon_ddt})  ocean and $\mu=0$ elsewhere. With this value, eqn. (\ref{carbon_ddt})
717  is valid as a prognostic equation for small perturbations in oceanic  is valid as a prognostic equation for small perturbations in oceanic
718  carbon concentrations. This configuration provides a  carbon concentrations. This configuration provides a
719  powerful tool for examining the impact of large-scale ocean circulation  powerful tool for examining the impact of large-scale ocean circulation
720  on $ CO_2 $ outgassing due to interior injections.  on $ CO_2 $ out-gassing due to interior injections.
721  As source we choose a constant in time injection of  As source we choose a constant in time injection of
722  $ S = 1 \,\, {\rm mol / s}$.  $ S = 1 \,\, {\rm mol / s}$.
723    
# Line 726  $4^\circ \times 4^\circ$ resolution hori Line 728  $4^\circ \times 4^\circ$ resolution hori
728  geography and bathymetry. Twenty vertical layers are used with  geography and bathymetry. Twenty vertical layers are used with
729  vertical spacing ranging  vertical spacing ranging
730  from 50 m near the surface to 815 m at depth.  from 50 m near the surface to 815 m at depth.
731  Driven to steady-state by climatalogical wind-stress, heat and  Driven to steady-state by climatological wind-stress, heat and
732  fresh-water forcing the model reproduces well known large-scale  fresh-water forcing the model reproduces well known large-scale
733  features of the ocean general circulation.  features of the ocean general circulation.
734    
735  \subsubsection{Outgassing cost function}  \subsubsection{Out-gassing cost function}
736    
737  To quantify and understand outgassing due to injections of $C$  To quantify and understand out-gassing due to injections of $C$
738  in eqn. (\ref{carbon_ddt}),  in eqn. (\ref{carbon_ddt}),
739  we define a cost function $ {\cal J} $ that measures the total amount of  we define a cost function $ {\cal J} $ that measures the total amount of
740  tracer outgassed at each timestep:  tracer out-gassed at each timestep:
741  %  %
742  \begin{equation}  \begin{equation}
743  \label{cost_tracer}  \label{cost_tracer}
744  {\cal J}(t=T)=\int_{t=0}^{t=T}\int_{A} \mu C \, dA \, dt  {\cal J}(t=T)=\int_{t=0}^{t=T}\int_{A} \mu C \, dA \, dt
745  \end{equation}  \end{equation}
746  %  %
747  Equation(\ref{cost_tracer}) integrates the outgassing term, $\mu C$,  Equation(\ref{cost_tracer}) integrates the out-gassing term, $\mu C$,
748  from (\ref{carbon_ddt})  from (\ref{carbon_ddt})
749  over the entire ocean surface area, $A$, and accumulates it  over the entire ocean surface area, $A$, and accumulates it
750  up to time $T$.  up to time $T$.
751  Physically, ${\cal J}$ can be thought of as representing the amount of  Physically, ${\cal J}$ can be thought of as representing the amount of
752  $CO_2$ that our model predicts would be outgassed following an  $CO_2$ that our model predicts would be out-gassed following an
753  injection at rate $S$.  injection at rate $S$.
754  The sensitivity of ${\cal J}$ to the spatial location of $S$,  The sensitivity of ${\cal J}$ to the spatial location of $S$,
755  $\frac{\partial {\cal J}}{\partial S}$,  $\frac{\partial {\cal J}}{\partial S}$,
756  can be used to identify regions from which circulation  can be used to identify regions from which circulation
757  would cause $CO_2$ to rapidly outgas following injection  would cause $CO_2$ to rapidly out-gas following injection
758  and regions in which $CO_2$ injections would remain effectively  and regions in which $CO_2$ injections would remain effectively
759  sequesterd within the ocean.  sequestered within the ocean.
760    
761  \subsection{Code configuration}  \subsection{Code configuration}
762    
763  The model configuration for this experiment resides under the  The model configuration for this experiment resides under the
764  directory {\it verification/carbon/}.  directory {\it verification/carbon/}.
765  The code customisation routines are in {\it verification/carbon/code/}:  The code customization routines are in {\it verification/carbon/code/}:
766  %  %
767  \begin{itemize}  \begin{itemize}
768  %  %
# Line 828  $ adjoint/ $: Line 830  $ adjoint/ $:
830  \end{itemize}  \end{itemize}
831  %  %
832    
833  Below we describe the customisations of this files which are  Below we describe the customizations of this files which are
834  specific to this experiment.  specific to this experiment.
835    
836  \subsubsection{File {\it .genmakerc}}  \subsubsection{File {\it .genmakerc}}
# Line 869  advection/diffusion of a passive tracer Line 871  advection/diffusion of a passive tracer
871  model integration. \\  model integration. \\
872  \hspace*{4ex} {\tt \#define ALLOW\_MIT\_ADJOINT\_RUN} \\  \hspace*{4ex} {\tt \#define ALLOW\_MIT\_ADJOINT\_RUN} \\
873  This flag enables the inclusion of some AD-related fields  This flag enables the inclusion of some AD-related fields
874  concerning initialisation, link between control variables  concerning initialization, link between control variables
875  and forward model variables, and the call to the top-level  and forward model variables, and the call to the top-level
876  forward/adjoint subroutine {\it adthe\_main\_loop}  forward/adjoint subroutine {\it adthe\_main\_loop}
877  instead of {\it the\_main\_loop}. \\  instead of {\it the\_main\_loop}. \\
# Line 905  enables the checkpointing feature of TAM Line 907  enables the checkpointing feature of TAM
907  (see Section \ref{???}).  (see Section \ref{???}).
908  In the present example a 3-level checkpointing is implemented.  In the present example a 3-level checkpointing is implemented.
909  The code contains the relevant store directives, common block  The code contains the relevant store directives, common block
910  and tape initialisations, storing key computation,  and tape initializations, storing key computation,
911  and loop index handling.  and loop index handling.
912  The checkpointing length at each level is defined in  The checkpointing length at each level is defined in
913  file {\it tamc.h}, cf. below.  file {\it tamc.h}, cf. below.
914  %  %
915  \item Cost function package: {\it pkg/cost/} \\  \item Cost function package: {\it pkg/cost/} \\
916  This package contains all relevant routines for  This package contains all relevant routines for
917  initialising, accumulating and finalizing the cost function  initializing, accumulating and finalizing the cost function
918  (see Section \ref{???}). \\  (see Section \ref{???}). \\
919  \hspace*{4ex} {\tt \#define ALLOW\_COST} \\  \hspace*{4ex} {\tt \#define ALLOW\_COST} \\
920  enables all general aspects of the cost function handling,  enables all general aspects of the cost function handling,
921  in particular the hooks in the foorward code for  in particular the hooks in the forward code for
922  initialising, accumulating and finalizing the cost function. \\  initializing, accumulating and finalizing the cost function. \\
923  \hspace*{4ex} {\tt \#define ALLOW\_COST\_TRACER} \\  \hspace*{4ex} {\tt \#define ALLOW\_COST\_TRACER} \\
924  includes the call to the cost function for this  includes the call to the cost function for this
925  particular experiment, eqn. (\ref{cost_tracer}).  particular experiment, eqn. (\ref{cost_tracer}).
# Line 956  model. It is identical to the {\it verif Line 958  model. It is identical to the {\it verif
958  \hspace*{4ex} {\tt sNx = 90} \\  \hspace*{4ex} {\tt sNx = 90} \\
959  \hspace*{4ex} {\tt sNy = 40} \\  \hspace*{4ex} {\tt sNy = 40} \\
960  \hspace*{4ex} {\tt Nr = 20} \\  \hspace*{4ex} {\tt Nr = 20} \\
961  It correpsponds to a single-tile/single-processor setup:  It corresponds to a single-tile/single-processor setup:
962  {\tt nSx = nSy = 1, nPx = nPy = 1},  {\tt nSx = nSy = 1, nPx = nPy = 1},
963  with standard overlap dimensioning  with standard overlap dimensioning
964  {\tt OLx = OLy = 3}.  {\tt OLx = OLy = 3}.
# Line 1035  The following parameters may be worth de Line 1037  The following parameters may be worth de
1037    
1038  \subsubsection{File {\it makefile}}  \subsubsection{File {\it makefile}}
1039    
1040  This file contains all relevant paramter flags and  This file contains all relevant parameter flags and
1041  lists to run TAMC or TAF.  lists to run TAMC or TAF.
1042  It is assumed that TAMC is available to you, either locally,  It is assumed that TAMC is available to you, either locally,
1043  being installed on your network, or remotely through the 'TAMC Utility'.  being installed on your network, or remotely through the 'TAMC Utility'.
# Line 1076  the gradient vector $ \nabla_v J $. Line 1078  the gradient vector $ \nabla_v J $.
1078  {\tt <file names>} refers to the list of files {\it .f} which are to be  {\tt <file names>} refers to the list of files {\it .f} which are to be
1079  analyzed by TAMC. This list is generally smaller than the full list  analyzed by TAMC. This list is generally smaller than the full list
1080  of code to be compiled. The files not contained are either  of code to be compiled. The files not contained are either
1081  above the top-level routine (some initialisations), or are  above the top-level routine (some initializations), or are
1082  deliberately hidden from TAMC, either because hand-written  deliberately hidden from TAMC, either because hand-written
1083  adjoint routines exist, or the routines must not (or don't have to)  adjoint routines exist, or the routines must not (or don't have to)
1084  be differentiated. For each routine which is part of the flow tree  be differentiated. For each routine which is part of the flow tree
# Line 1091  for TAMC. Line 1093  for TAMC.
1093  \end{itemize}  \end{itemize}
1094    
1095    
1096  \subsubsection{File {\it data}}  \subsubsection{The input parameter files}
1097    
1098  \subsubsection{File {\it data.cost}}  \paragraph{File {\it data}}
1099    
1100  \subsubsection{File {\it data.ctrl}}  \paragraph{File {\it data.cost}}
1101    
1102  \subsubsection{File {\it data.gmredi}}  \paragraph{File {\it data.ctrl}}
1103    
1104  \subsubsection{File {\it data.grdchk}}  \paragraph{File {\it data.gmredi}}
1105    
1106  \subsubsection{File {\it data.optim}}  \paragraph{File {\it data.grdchk}}
1107    
1108  \subsubsection{File {\it data.pkg}}  \paragraph{File {\it data.optim}}
1109    
1110  \subsubsection{File {\it eedata}}  \paragraph{File {\it data.pkg}}
1111    
1112  \subsubsection{File {\it topog.bin}}  \paragraph{File {\it eedata}}
1113    
1114  \subsubsection{File {\it windx.bin, windy.bin}}  \paragraph{File {\it topog.bin}}
1115    
1116  \subsubsection{File {\it salt.bin, theta.bin}}  \paragraph{File {\it windx.bin, windy.bin}}
1117    
1118  \subsubsection{File {\it SSS.bin, SST.bin}}  \paragraph{File {\it salt.bin, theta.bin}}
1119    
1120  \subsubsection{File {\it pickup*}}  \paragraph{File {\it SSS.bin, SST.bin}}
1121    
1122  \subsection{Compiling the model and its adjoint}  \paragraph{File {\it pickup*}}
1123    
1124    \subsection{Compiling the model and its adjoint}
1125    
1126    The built process of the adjoint model is slightly more
1127    complex than that of compiling the forward code.
1128    The main reason is that the adjoint code generation requires
1129    a specific list of routines that are to be differentiated
1130    (as opposed to the automatic generation of a list of
1131    files to be compiled by genmake).
1132    This list excludes routines that don't have to be or must not be
1133    differentiated. For some of the latter routines flow directives
1134    may be necessary, a list of which has to be given as well.
1135    For this reason, a separate {\it makefile} is currently
1136    maintained in the directory {\tt adjoint/}. This
1137    makefile is responsible for the adjoint code generation.
1138    
1139    In the following we describe the build process step by step,
1140    assuming you are in the directory {\tt bin/}.
1141    A summary of steps to follow is given at the end.
1142    
1143    \paragraph{Adjoint code generation and compilation -- step by step}
1144    
1145    \begin{enumerate}
1146    %
1147    \item
1148    {\tt ln -s ../verification/???/code/.genmakerc .} \\
1149    {\tt ln -s ../verification/???/code/*.[Fh] .} \\
1150    Link your customized genmake options, header files,
1151    and modified code to the compile directory.
1152    %
1153    \item
1154    {\tt ../tools/genmake -makefile} \\
1155    Generate your Makefile (cf. Section ???).
1156    %
1157    \item
1158    {\tt make depend} \\
1159    Dependency analysis for the CPP pre-compiler (cf. Section ???).
1160    %
1161    \item
1162    {\tt make small\_f} \\
1163    This is the first difference between forward code compilation
1164    and adjoint code generation and compilation.
1165    Instead of going through the entire compilation process
1166    (CPP precompiling -- {\tt .f}, object code generation -- {\tt .o},
1167    linking of object files and libraries to generate executable),
1168    only the CPP compiler is invoked at this stage to generate
1169    the {\tt .f} files.
1170    %
1171    \item
1172    {\tt cd ../adjoint} \\
1173    {\tt make adtaf} or {\tt make adtamc} \\
1174    Depending on whether you have TAF or TAMC at your disposal,
1175    you'll choose {\tt adtaf} or {\tt adtamc} as your
1176    make target for the {\it makefile} in the directory {\tt adjoint/}.
1177    Several things happen at this stage.
1178    %
1179    \begin{enumerate}
1180    %
1181    \item
1182    The initial template file {\it adjoint\_model.F} which is part
1183    of the compiling list created by {\it genmake} is restored.
1184    %
1185    \item
1186    All Fortran routines {\tt *.f} in {\tt bin/} are
1187    concatenated into a single file (it's current name is
1188    {\it tamc\_code.f}).
1189    %
1190    \item
1191    Adjoint code is generated by TAMC or TAF.
1192    The adjoint code is written to the file {\it tamc\_code\_ad.f}.
1193    It contains all adjoint routines of the forward routines
1194    concatenated in {\it tamc\_code.f}.
1195    For a given forward routines {\tt subroutine routinename}
1196    the adjoint routine is named {\tt adsubroutine routinename}
1197    by default (that default can be changed via the flag
1198    {\tt -admark <markname>}).
1199    Furthermore, it may contain modified code which
1200    incorporates the translation of adjoint store directives
1201    into specific Fortran code.
1202    For a given forward routines {\tt subroutine routinename}
1203    the modified routine is named {\tt mdsubroutine routinename}.
1204    TAMC or TAF info is written to file
1205    {\it tamc\_code.prot} or {\it taf.log}, respectively.
1206    %
1207    \end{enumerate}
1208    %
1209    \item
1210    {\tt make adchange} \\
1211    The multi-threading capability of the MITGCM requires a slight
1212    change in the parameter list of some routines that are related to
1213    to active file handling.
1214    This post-processing invokes the sed script {\it adjoint\_ecco\_sed.com}
1215    to insert the threading counter {\bf myThId} into the parameter list
1216    of those subroutines.
1217    The resulting code is written to file {\it tamc\_code\_sed\_ad.f}
1218    and appended to the file {\it adjoint\_model.F}.
1219    This concludes the adjoint code generation.
1220    %
1221    \item
1222    {\tt cd ../bin} \\
1223    {\tt make} \\
1224    The file {\it adjoint\_model.F} now contains the full adjoint code.
1225    All routines are now compiled.
1226    %
1227    \end{enumerate}
1228    
1229    \paragraph{Adjoint code generation and compilation -- summary}
1230    ~ \\
1231    
1232    \[
1233    \boxed{
1234    \begin{split}
1235     ~ & \mbox{\tt cd bin} \\
1236     ~ & \mbox{\tt ln -s ../verification/my\_experiment/code/.genmakerc .} \\
1237     ~ & \mbox{\tt ln -s ../verification/my\_experiment/code/*.[Fh] .} \\
1238     ~ & \mbox{\tt ../tools/genmake -makefile} \\
1239     ~ & \mbox{\tt make depend} \\
1240     ~ & \mbox{\tt make small\_f} \\
1241     ~ & \mbox{\tt cd ../adjoint} \\
1242     ~ & \mbox{\tt make adtaf <OR: make adtamc>} \\
1243     ~ & \mbox{\tt make adchange} \\
1244     ~ & \mbox{\tt cd ../bin} \\
1245     ~ & \mbox{\tt make} \\
1246    \end{split}
1247    }
1248    \]
1249    
1250  \newpage  \newpage
1251    
# Line 1136  differentiation using the software tool Line 1264  differentiation using the software tool
1264  \label{fig:adthemodel}  \label{fig:adthemodel}
1265  \end{figure}  \end{figure}
1266    
1267  The basic flow is depicted in \reffig{adthemodel}.  The basic flow is depicted in \ref{fig:adthemodel}.
1268  If the option {\tt ALLOW\_AUTODIFF\_TAMC} is defined, the driver routine  If the option {\tt ALLOW\_AUTODIFF\_TAMC} is defined, the driver routine
1269  {\it the\_model\_main}, instead of calling {\it the\_main\_loop},  {\it the\_model\_main}, instead of calling {\it the\_main\_loop},
1270  invokes the adjoint of this routine, {\it adthe\_main\_loop},  invokes the adjoint of this routine, {\it adthe\_main\_loop},
# Line 1168  $ {\cal J}(\vec{u}) \, = \, {\cal J}(M(\ Line 1296  $ {\cal J}(\vec{u}) \, = \, {\cal J}(M(\
1296  The input is referred to as the  The input is referred to as the
1297  {\sf independent variables} or {\sf control variables}.  {\sf independent variables} or {\sf control variables}.
1298  All aspects relevant to the treatment of the cost function $ {\cal J} $  All aspects relevant to the treatment of the cost function $ {\cal J} $
1299  (parameter setting, initialisation, accumulation,  (parameter setting, initialization, accumulation,
1300  final evaluation), are controlled by the package {\it pkg/cost}.  final evaluation), are controlled by the package {\it pkg/cost}.
1301    
1302  \begin{figure}[h!]  \begin{figure}[h!]
# Line 1217  automatic differentiation, the CPP optio Line 1345  automatic differentiation, the CPP optio
1345  {\bf ALLOW\_ADJOINT\_RUN} should be defined  {\bf ALLOW\_ADJOINT\_RUN} should be defined
1346  (file {\it CPP\_OPTIONS.h}).  (file {\it CPP\_OPTIONS.h}).
1347    
1348  \subsubsection{Initialisation}  \subsubsection{Initialization}
1349  %  %
1350  The initialisation of the {\it cost} package is readily enabled  The initialization of the {\it cost} package is readily enabled
1351  as soon as the CPP option {\bf ALLOW\_ADJOINT\_RUN} is defined.  as soon as the CPP option {\bf ALLOW\_ADJOINT\_RUN} is defined.
1352  %  %
1353  \begin{itemize}  \begin{itemize}
# Line 1250  Variables: {\it cost\_init} Line 1378  Variables: {\it cost\_init}
1378  }  }
1379  \\  \\
1380  This S/R  This S/R
1381  initialises the different cost function contributions.  initializes the different cost function contributions.
1382  The contribtion for the present example is {\bf objf\_tracer}  The contribution for the present example is {\bf objf\_tracer}
1383  which is defined on each tile (bi,bj).  which is defined on each tile (bi,bj).
1384  %  %
1385  \end{itemize}  \end{itemize}
# Line 1327  as variable assignments. Therefore, file Line 1455  as variable assignments. Therefore, file
1455  active variables are written and from which active variables  active variables are written and from which active variables
1456  are read are called {\sf active files}.  are read are called {\sf active files}.
1457  All aspects relevant to the treatment of the control variables  All aspects relevant to the treatment of the control variables
1458  (parameter setting, initialisation, perturbation)  (parameter setting, initialization, perturbation)
1459  are controled by the package {\it pkg/ctrl}.  are controlled by the package {\it pkg/ctrl}.
1460    
1461  \begin{figure}[h!]  \begin{figure}[h!]
1462  \input{part5/doc_ctrl_flow}  \input{part5/doc_ctrl_flow}
# Line 1354  To enable the directory to be included t Line 1482  To enable the directory to be included t
1482  Each control variable is enabled via its own CPP option  Each control variable is enabled via its own CPP option
1483  in {\it ECCO\_CPPOPTIONS.h}.  in {\it ECCO\_CPPOPTIONS.h}.
1484    
1485  \subsubsection{Initialisation}  \subsubsection{Initialization}
1486  %  %
1487  \begin{itemize}  \begin{itemize}
1488  %  %
# Line 1394  Two important issues related to the hand Line 1522  Two important issues related to the hand
1522  variables in the MITGCM need to be addressed.  variables in the MITGCM need to be addressed.
1523  First, in order to save memory, the control variable arrays  First, in order to save memory, the control variable arrays
1524  are not kept in memory, but rather read from file and added  are not kept in memory, but rather read from file and added
1525  to the initial fields during the model initialisation phase.  to the initial fields during the model initialization phase.
1526  Similarly, the corresponding adjoint fields which represent  Similarly, the corresponding adjoint fields which represent
1527  the gradient of the cost function w.r.t. the control variables  the gradient of the cost function w.r.t. the control variables
1528  are written to file at the end of the adjoint integration.  are written to file at the end of the adjoint integration.
# Line 1474  dummy variable {\bf xx\_tr1\_dummy} is i Line 1602  dummy variable {\bf xx\_tr1\_dummy} is i
1602  and an 'active read' routine of the adjoint support  and an 'active read' routine of the adjoint support
1603  package {\it pkg/autodiff} is invoked.  package {\it pkg/autodiff} is invoked.
1604  The read-procedure is tagged with the variable  The read-procedure is tagged with the variable
1605  {\bf xx\_tr1\_dummy} enabbling TAMC to recognize the  {\bf xx\_tr1\_dummy} enabling TAMC to recognize the
1606  initialisation of the perturbation.  initialization of the perturbation.
1607  The modified call of TAMC thus reads  The modified call of TAMC thus reads
1608  %  %
1609  \begin{verbatim}  \begin{verbatim}
# Line 1586  variables are written to {\bf adxx\_ ... Line 1714  variables are written to {\bf adxx\_ ...
1714  \begin{itemize}  \begin{itemize}
1715  %  %
1716  \item {\bf vector\_ctrl}: the control vector \\  \item {\bf vector\_ctrl}: the control vector \\
1717  At the very beginning of the model initialisation,  At the very beginning of the model initialization,
1718  the updated compressed control vector is read (or initialised)  the updated compressed control vector is read (or initialised)
1719  and distributed to 2-dim. and 3-dim. control variable fields.  and distributed to 2-dim. and 3-dim. control variable fields.
1720  %  %

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