Batch Processing

When you launch Tecplot 360 in batch mode, you provide the name of a macro file to execute. The minimal command to launch Tecplot 360 in batch mode is as follows:

The -b flag instructs Tecplot 360 to run in batch mode and the -p tells Tecplot 360 to run the filename that follows (mymacrofile.mcr in this case).

Combining layout files with batch processing is both powerful and flexible, and is also the recommended procedure. With layout files, you can organize a plot using one or more frames in a single file. The layout file manages datasets and can be altered on the fly, either on the command line or within a macro that loads the layout file.

For example, to do the following sequence of tasks in batch mode:

You can set up the batch script as follows:

In Batch Processing Using a Layout File, we set up Tecplot 360 to process a user-supplied data file (or files) and create a single output file. If the above procedure is to be repeated for a large number of input files (one at a time), you can do this by using a loop: either outside Tecplot 360 in the operating system using your shell’s looping constructs, or within Tecplot 360 using the flow-of-control commands in the Tecplot macro language.

Each time Tecplot 360 is run in batch mode, it creates a file defined by the name in the BATCHLOGFILE environment variable, or, if the environment variable is not defined, by a file named batch.log in the directory where Tecplot 360 was started. If the name given in the BATCHLOGFILE environment variable is a relative path, the directory name where Tecplot 360 was started is prefixed. A running commentary on actions performed in Tecplot 360, as well as warning and error messages, are sent to the batch.log file.

Two of Tecplot 360’s command line options, -o and -convert, allow you to more easily convert your existing datasets to SZL, Tecplot’s high-performance subzone data format (filename extension .szplt). Since it is command-line driven, this capability is suitable for converting large numbers of files without user intervention, or as a step in solver postprocessing.

Tecplot 360 does not require a license when launched with either of these options, so you can perform data file conversion on any available workstation without concern. Only a Tecplot 360 installation is required.

In a restricted batch session started with -o or -convert, Tecplot 360 can read data files (using any of its data loader add-ons) and write data in SZL format, but cannot perform most other operations. As with all batch operations, there is no graphical user interface; batch conversion is strictly a command-line function.

Most of the time, you’ll want to use the -o option for SZL conversion. See Writing SZL Files With Macros for more information on the use cases for the -convert option.

Loading Data Files by Name

The -o option outputs any loaded data to the specified .szplt output file. Just add -o followed by the output filename or path to whatever command line you would normally use to load your data. Tecplot 360 will then write that data in SZL format (and exit) instead of displaying a plot in its workspace. For example, if you usually start exploring data in two Tecplot .plt files using the following command line:

You can instead have Tecplot 360 convert those data files to a single .szplt file using the following command line:

If your data is in a non-Tecplot format, you may or may not be able to load it all into Tecplot 360 using a single, simple command line of the type shown. Some formats (e.g. CGNS) support loading multpile files, but require that the files all be part of a single case, and require additional cases to be appended via further load operations. Other loaders do not support multiple files at all and require all loads after the first to be appended. In such cases, you can record a macro to load your data.

Loading Data Files with Macros

Create a macro to load some or all of your data when one or more of the following apply:

Simply record a macro that loads the data, using the procedure you normally use with the Tecplot 360 graphical user interface. See Macro Creation for more information on recording macros.

The loading procedure you record can include multiple load operations using the append option, any number of different file formats, and selection of advanced loader options. After you have recorded the macro, specify it on the command line when invoking tec360. As with the previous case, simply add -o followed by the name of SZL file to be created:

Your recorded macro contains fixed file names and directory paths for the files you loaded, which makes it difficult to use the macro with other data files. We will see how to address this with a few simple changes to the macro shortly.

Using Multiple Macros to Load Files

Tecplot 360 allows you to specify multiple macros on the command line, which will be executed in the order they appear in the command. Instead of creating one macro that loads multiple files, then, you could record multiple macros, each loading one data file, then specify just the ones you actually need for a given project. For example:

Combined with the techniques in the following sections to allow the macros to load data files other than the ones used when recording the macro, this lets you create a macro "tool set" for converting the various kinds of files you typically work with.

There is one hitch to using multiple macros on the command line. When you record a load operation, the resulting macro may include an instruction telling the loader to erase any data that has already been loaded. When you attempt to load your data, the second macro file specified will erase the data loaded by the first, and so on for the third, fourth, etc., wasting time and making it seem like only the last macro loaded anything.

Fortunately, this is easy to fix. Simply load the macro into any text editor (Notepad.exe will do) and find any lines that says READDATAOPTION = NEW. Change it to say READDATAOPTION = APPEND instead. Such a macro will still work fine even when specified first on the command line, because each conversion is a new Tecplot 360 session that begins with no data loaded.

Mixing Macros and Data Files

Macros are just another kind of data file: one that Tecplot 360 happens to execute as instructions. For this reason, it is possible to mix data files and macros on the command line to load your data, using macros only for files that can’t be loaded by specifying them directly. Files are processed in the order they appear on the command line. For example:

This loads cube.plt (a regular Tecplot data file) and then executes loadcircle.mcr, which, presumably, loads another data file (or even multiple files). The loaded data are then written to output.szplt.

Using Relative Paths

As we mentioned, the paths of the files you loaded and saved become a part of recorded macros. The macro will then always load input files with the same names, and in the same directory, as the file(s) used when the macro was recorded. The output file, similarly, is always given exactly the same name and stored in the same directory as the one you wrote while recording the macro.

If you have set up your simulation process so that the solver always produces an output file of the same name, but in a different directory for each case, you can simply edit the recorded macro to use relative paths. Then the macro will work with files in the current directory, whatever it may be, and you can simply change to the directory that contains the file you wish to convert before performing the conversion.

For example, here is a simple macro, loadcube.mcr, that we recorded to load a single .plt file. (A real macro would probably be longer, since you don’t even need a macro to load a .plt file, but let’s keep it simple.)

All recorded macros contain a definition of the variable MFBD, which refers to the current (or working) directory that was in effect when the macro was recorded. Since we loaded cube.plt from our Desktop folder, which was also the working directory, the macro uses the MFBD variable in the READDATASET command. If we had loaded our data file from a directory other than the working directory, the READDATASET command would have the full path (for example, on Windows, it would probably start with C:\). Here’s what the macro looks like when cube.plt is in `C:\:

We don’t actually need the MFBD variable for our purposes, so we can remove the VarSet command and the corresponding RemoveVar command. (It doesn’t hurt to leave them, however.) We will also remove everything but the filename from the READDATASET and WRITEDATASET commands. We will also change the READDATAOPTION to APPEND, as suggested in the preceding section. Here is the macro after these changes.

This macro now reads the cube.plt file from the current (or working) directory. After saving it as loadcube.mcr, you can invoke the conversion as follows:

Note that, when invoking the conversion, we must specify the full path to convert.mcr since it is not in the working directory. If the Tecplot 360 bin directory is not in your system’s PATH variable, you must also supply the full path to the tec360 executable. (For simplicity, our examples assume tec360 is in your PATH.)

Using Environment Variables in Loader Macros

When the data files you want to convert may have different names, but are in the same format and need the same loader options, it is possible to write a macro that accepts paths specified outside of the macro. The most straightforward way to do this is to set environment variables before launching Tecplot 360. The macro file then uses these environment variables as the input file path(s). Here, we will use the variable INFILE with the macro from the preceding section. Since it will no longer load only cube.plt, we will name the macro loaddata.mcr rather than loadcube.mcr.

To invoke it, set the environment variables before starting the conversion:

Windows:

Linux or Mac (bash shell):

Either absolute or relative paths may be used in environment variables; relative paths are, as always, relative to the current or working directory.

If your file loading process requires you to specify more than one input file to a macro, simply add an INFILE variable for each, appending numbers such as INFILE1, INFILE2, etc. and change your macro accordingly. If you will be using multiple macros, use different variables in each so that they don’t conflict.

A Batch File for Conversion

The command line instructions in the preceding section can be put into a batch file (Windows) or a shell script (Linux or Mac) so that you can specify all the necessary paths in a single command line. This file (convert.bat or convert.sh) can be placed in the same directory as our loaddata.mcr from the preceding section, as long as that directory is in your system’s PATH.

Windows — convert.bat:

Now you may invoke it as follows:

Linux or Mac OS — convert.sh:

After creating convert.sh, execute the command below to make it executable:

The script may then be invoked as follows:

The same technique can be used with additional macro files and additional filenames; you will simply need to set the environment variable(s) needed by each macro based on the arguments to the script (%1, %2, etc. in Windows batch files or $1, $2, etc. in Linux or Mac bash scripts).

Writing SZL Files With Macros

The principal difference between -o and -convert is that when you use -o, Tecplot 360 writes SZL data for you, whereas with -convert, you write the data file using a macro. All that we have already learned about using macros still applies; the following are valid scenarios:

You can create a macro file that writes a .szplt file by recording a save operation, but here, for the record, is the necessary command:

You can adapt this macro to use relative paths or an environment variable, as we have already done with the macros we created to load data. Here is the macro rewritten to use the environment variable OUTFILE:

The circumstances in which you might use -convert instead of -o are fairly limited. One use might be to write multiple copies of the .szplt file, for example to make a backup (though using the COPY or cp shell command is probably better).

Another use might be to automatically name the .szplt file based on some attribute of the loaded data, rather than requiring a name to be specified. Keep in mind that in the restricted macro environment provided when using -convert, the ability to inspect and analyze data is extremely limited. However, you could name a file based on the date, or on an auxiliary data element (using the AUXDATASET, AUXFRAME, or AUXZONE intristic variables) — or a combination of these:, such as

The variable DATASETFNAME contains the full paths of loaded data file(s) and can be used to give the output file the same base name as an input file. Since this variable can contain multiple paths if you have loaded multiple files, we recommend always using an index with it to specify which path you want; otherwise, the paths of all loaded files are substituted into the command, which will cause the save to fail.

You may use |DATASETFNAME[2]|, |DATASETFNAME[3]|, and so on to refer to the path of a specific file, indexed by loading sequence.

For a full list of available macro variables, see the Scripting Guide for more information.