************* Contour Plots ************* Description =========== Contour plots are a very general plot type somewhat similar to a scatter plot. The axes are specified by the user, and any will do so long as the entire set of x and y locations has some value (i.e. not missing data). The value is then contoured. This type of plot is often used to examine statistics over a series of time or heights. For more information on Contour plots, please refer to the `METviewer documentation `_. .. image:: figure/contour.png Example ======= Sample Data ----------- The data is text output from MET in columnar format. The sample data used to create these plots is available in the METplotpy repository: *$METPLOTPY_BASE/test/contour/contour.data* *$METPLOTPY_BASE* is the directory where the METplotpy code is saved: e.g. */usr/path/to/METplotpy* if the source code was cloned or forked from the Github repository or */usr/path/to/METplotpy-x.y.z* if the source code was downloaded as a zip or gzip'd tar file from the Release link of the Github repository. The *x.y.z* is the release number. Configuration Files ------------------- The contour plot utilizes YAML configuration files to indicate where input data is located and to set plot attributes. These plot attributes correspond to values that can be set via the METviewer tool. YAML is a recursive acronym for "YAML Ain't Markup Language" and according to `yaml.org `_, it is a "human-friendly data serialization language. It is commonly used for configuration files and in applications where data is being stored or transmitted. Two configuration files are required. The first is a default configuration file, **contour_defaults.yaml**, which is found in the *$METPLOTPY_BASE/metplotpy/plots/config* directory. *$METPLOTPY_BASE* indicates the directory where the METplotpy source code has been saved. All default configuration files are located in the *$METPLOTPY_BASE/metplotpy/plots/config* directory. **Default configuration files are automatically loaded by the plotting code and do not need to be explicitly specified when generating a plot**. The second required configuration file is a user-supplied “custom” configuration file. This file is used to customize/override the default settings in the **contour_defaults.yaml** file. METplus Configuration ===================== Default Configuration File -------------------------- The following is the *mandatory*, **contour_defaults.yaml** configuration file, which serves as a starting point for creating a contour plot, as it represents the default values set in METviewer. **NOTE**: This default configuration file is automatically loaded by **contour.py.** .. literalinclude:: ../../metplotpy/plots/config/contour_defaults.yaml In the default config file, logging is set to stdout and the log level is ERROR (i.e. only log messages of type ERROR will be logged). If the log_filename and log_level are not specified in the custom configuration file, these settings will be used. Custom Configuration File ------------------------- A second, *mandatory* configuration file is required, which is used to customize the settings to the contour plot. The **custom_contour.yaml** file is included with the source code and looks like the following: .. literalinclude:: ../../test/contour/custom_contour.yaml Copy this custom config file from the directory where the source code was saved to the working directory: .. code-block:: ini cp $METPLOTPY_BASE/test/contour/custom_contour.yaml $WORKING_DIR/custom_contour.yaml Modify the *stat_input* setting in the *$METPLOTPY_BASE/test/contour/custom_contour.yaml* file to explicitly point to the *$METPLOTPY_BASE/test/contour* directory (where the custom config files and sample data reside). Replace the relative path *./contour.data* with the full path *$METPLOTPY_BASE/test/contour/contour.data* (including replacing *$METPLOTPY_BASE* with the full path to the METplotpy installation on the system). Modify the *plot_filename* setting to point to the output path where the plot will be saved, including the name of the plot. For example: *stat_input: /username/myworkspace/METplotpy/test/contour/contour.data* *plot_filename: /username/working_dir/output_plots/contour_custom.png* This is where */username/myworkspace/METplotpy* is $METPLOTPY_BASE and */username/working_dir* is $WORKING_DIR. Make sure that the $WORKING_DIR directory that is specified exists and has the appropriate read and write permissions. The path listed for *plot_filename* may be changed to the output directory of one’s choosing. If this is not set, then the *plot_filename* setting specified in the *$METPLOTPY_BASE/metplotpy/plots/config/contour_defaults.yaml* configuration file will be used. To save the intermediate **.points1** file (used by METviewer and useful for debugging), set the *dump_points_1* setting to True. Uncomment or add (if it doesn't exist) the *points_path* setting: *dump_points_1: 'True'* *points_path: '/dir_to_save_points1_file'* Replace the */dir_to_save_points1_file* to the same directory where the **.points1** file is saved. If *points_path* is commented out (indicated by a '#' symbol in front of it), remove the '#' symbol to uncomment the *points_path* so that it will be used by the code. Make sure that this directory exists and has the appropriate read and write permissions. **NOTE**: the *points_path* setting is **optional** and does not need to be defined in the configuration file unless saving the intermediate **.points1** file is desired. To save the log output to a file, uncomment the *log_filename* entry and specify the path and name of the log file. Select a directory with the appropriate read and write privileges. To modify the verbosity of logging than what is set in the default config file, uncomment the *log_level* entry and specify the log level (debug and info are higher verbosity, warning and error are lower verbosity). Run from the Command Line ========================= To generate a contour plot (i.e. using settings in the **custom_contour.yaml** configuration file), perform the following: * If using the conda environment, verify the conda environment is running and has has the required Python packages outlined in the `requirements section. `_ * Set the METPLOTPY_BASE environment variable to point to *$METPLOTPY_BASE*. For the ksh environment: .. code-block:: ini export METPLOTPY_BASE=$METPLOTPY_BASE For the csh environment: .. code-block:: ini setenv METPLOTPY_BASE $METPLOTPY_BASE Recall that *$METPLOTPY_BASE* is the directory path indicating where the METplotpy source code was saved. * Run the following on the command line: .. code-block:: ini python $METPLOTPY_BASE/metplotpy/plots/contour/contour.py $WORKING_DIR/custom_contour.yaml This will create a PNG file, **contour.png**, in the directory that was specified in the *plot_filename* setting of the **custom_contour.yaml** config file: .. image:: figure/contour.png * A **contour.png** output file will be created in the directory that was specified in the *plot_filename* config setting in the **custom_contour.yaml** config file.