Ganymed 1.0 User's Guide: Difference between revisions
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cvs co -r ''TAGNAME'' -d ''DIRECTORY'' Fortuna | cvs co -r ''TAGNAME'' -d ''DIRECTORY'' Fortuna | ||
where ''TAGNAME'' is the model "tag" (version). A tag in <code>cvs</code> marks the various versions of the source files in the repository that together make up a particular version of the model. A sample release tag is <code> | where ''TAGNAME'' is the model "tag" (version). A tag in <code>cvs</code> marks the various versions of the source files in the repository that together make up a particular version of the model. A sample release tag is <code>Ganymed-1_0_p7</code>, indicating the latest patch of version Ganymed 1.0. ''DIRECTORY'' is the directory that the source code tree will be created. If you are using a stock model tag it is reasonable to name the directory the same as the tag. This directory determines which model in presumably your space a particular experiment is using. Some scripts use the environment variable <code>ESMADIR</code>, which should be set to the absolute (full) pathname of this directory. | ||
When a modified version of some component of the model is saved to the repository, the tag it uses -- different from the standard model tag -- is supposed to be applied at most only to the directories with modified files. This means that if you need to use some variant tag of a gridded component, you will have to <code>cd</code> to that directory and update to the variant tag. So, for example, if you needed to apply updates to the SatSim gridded component, you would have to <code>cd</code> several levels down to the directory <code>GEOSsatsim_GridComp</code> and run | When a modified version of some component of the model is saved to the repository, the tag it uses -- different from the standard model tag -- is supposed to be applied at most only to the directories with modified files. This means that if you need to use some variant tag of a gridded component, you will have to <code>cd</code> to that directory and update to the variant tag. So, for example, if you needed to apply updates to the SatSim gridded component, you would have to <code>cd</code> several levels down to the directory <code>GEOSsatsim_GridComp</code> and run | ||
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===Outputting Derived Fields=== | ===Outputting Derived Fields=== | ||
In addition to writing export fields created by model components (we will refer to these as model fields), the user may specify new fields that will be evaluated using the MAPL parser. These will be referred to as derived fields in the following discussion. The derived fields are evaluated using an expression that involves other fields in the collection as variables. The expression is evaluated element by element to create a new field. Derived fields are specified like a regular field from a gridded component in a history collection with 3 comma separated strings. The difference is now that in place of a variable name string, an expression string that will be evaluated is entered. Following this comes the string specifying the gridded component. You MUST put a string here, which should be the name of a gridded component. Finally a string MUST be entered which is the name of the new variable. This will be the name of the variable in the output file. In general the expression entered will involve variables, functions, and real numbers. The derived fields are evaluated before time and spatial (vertical and horizontal) averaging. | In addition to writing export fields created by model components (we will refer to these as model fields), the user may specify new fields that will be evaluated using the MAPL parser. These will be referred to as derived fields in the following discussion. The derived fields are evaluated using an expression that involves other fields in the collection as variables. The expression is evaluated element by element to create a new field. Derived fields are specified like a regular field from a gridded component in a history collection with 3 comma separated strings. The difference is now that in place of a variable name string, an expression string that will be evaluated is entered. Following this comes the string specifying the gridded component. You MUST put a string here, which should be the name of a gridded component. Finally a string MUST be entered which is the name of the new variable. This will be the name of the variable in the output file. In general the expression entered will involve variables, functions, and real numbers. The derived fields are evaluated before time and spatial (vertical and horizontal) averaging. You will notice this when you compare a regridded derived field output by history to the same derived field evaluated from the constiuent fields also regridded by history in grads as the results will not be exactly the same when evaluating a non-linear expression (think something like sqrt(U*U+V*V)). | ||
Here are some rules about expressions | Here are some rules about expressions |