METplus Practical Session Guide (Version 4.0) | METplotpy > Wind Rose

Wind Rose Overview

 

The wind rose diagram source code is located in the https://github.com/dtcenter/METplotpy repository, under the METplotpy/metplotpy/plots/wind_rose directory.  Custom configuration files and sample data are located under the METplotpy/test/wind_rose directory.  

Detailed information about the wind rose diagram is available from Read the Docs:

https://metplotpy.readthedocs.io/en/latest/Users_Guide/wind_rose.html

These instructions are relevant for generating the wind rose diagram from the command line.  For METplotpy versions 1.0 and 1.1, development was performed with Python 3.6 and related third-party packages (i.e. Python packages outside the Python standard library).  Future releases of METplotpy will be based on Python version 3.8.6.  

The wind rose diagram requires two configuration files, a default and custom configuration file in YAML (https://yaml.org/).   The default configuration file is automatically loaded by the source code.  The custom configuration file is useful for overriding the default settings in the wind_rose_defaults.yaml configuration file.  If the user chooses to use all the settings in the default configuration file, an empty custom configuration file can be provided (however, the user will have the sample data and output plot located in the directories specified in the default configuration file.  Some users may not have permission to do this) .  The custom configuration files and sample data are located in the METplotpy/test/wind_rose directory of the downloaded/cloned source code.  The default configuration file, wind_rose_defaults.yml is located in the METplotpy/metplotpy/plots/config directory. 

 

Set up pre-requisites:

The Python requirements for METplotpy are found in the User's Guide, under the Installation section

METcalcpy is a requirement for METplotpy.  The following description is one of numerous methods to set up the working environment to utilize METcalcpy from the METplotpy source code.   These instructions are suitable for users that are not working within a conda environment:

Clone the METcalcpy repository to a directory where you have read/write permissions (replace /path/to/code with the full path to where you are saving the METcalcpy source code):
mkdir /path/to/code
cd /path/to/code
git clone https://github.com/dtcenter/METcalcpy

 

Set the PYTHONPATH to indicate where the METcalcpy modules can be found:

*Replace /path/to/code with the full path to where you saved the METcalcpy source code

csh:

setenv PYTHONPATH /path/to/code/METcalcpy:/path/to/code/METcalcpy/metcalcpy

bash:

export PYTHONPATH=/path/to/code/METcalcpy:/path/to/code/METcalcpy/metcalcpy

 

The following instructions are for users who have permission to create, modify, and use conda environments (skip if you already set the PYTHONPATH above).  Select either Method 1 or Method 2:
  • Method 1: Follow instructions in Section 1.1.2 of the Installation section of the METplotpy User's Guide
  • Method 2: Using using PyPI (Python Package Index) enter the following:
pip install metcalcpy==1.1

 

Create the Wind Rose diagram:

Overview of steps:

  • create a directory where you wish to save the METplotpy source code
  • create a WORKING_DIR where you have read/write permissions
  • set the WORKING_DIR, METPLOTPY_BASE, and PYTHONPATH environments
  • copy the wind rose sample data to the WORKING_DIR
  • copy the wind rose custom configuration file to the WORKING_DIR
  • modify the location of the input data and output plot in the custom configuration file
  • run the Python script to generate the wind rose diagram 

 

Replace /path/to with the full path to the METplotpy source code and working_dir 

mkdir /path/to
mkdir /path/to/working_dir

 

csh:

setenv PYTHONPATH /path/to/METcalcpy:/path/to/METcalcpy/metcalcpy:/path/to/METplotpy:/path/to/METplotpy/metplotpy:/path/to/METplotpy/metplotpy/plots
setenv METPLOTPY_BASE/path/to/METplotpy
setenv WORKING_DIR /path/to/working_dir/wind_rose

bash:

export PYTHONPATH=/path/to/METcalcpy:/path/to/METcalcpy/metcalcpy:/path/to/METplotpy:/path/to/METplotpy/metplotpy:/path/to/METplotpy/metplotpy/plots
export METPLOTPY_BASE=/path/to/METplotpy
export WORKING_DIR=/path/to/working_dir

 

Copy data and custom config file to WORKING_DIR:
cp $METPLOTPY_BASE/test/wind_rose/point_stats_mpr.txt $WORKING_DIR
cp $METPLOTPY_BASE/test/wind_rose/wind_rose_custom.yaml $WORKING_DIR
cd $WORKING_DIR

 

Modify the custom configuration file:

Open the wind_rose_custom.yaml file in a text editor of your choice.  Modify the stat_input and plot_filename to point explicitly to the location of the input data you copied and the name and location of the output plot:
stat_input: /path/to/working_dir/wind_rose/point_stats_mpr.txt
plot_filename: /path/to/working_dir/wind_rose/wind_rose_custom.png

Save and close the wind_rose_custom.yaml file. 

Generate the wind rose diagram:
python $METPLOTPY_BASE/metplotpy/plots/wind_rose/wind_rose.py $WORKING_DIR/wind_rose/wind_rose_custom.yaml

 

In your WORKING_DIR, you will now see a wind_rose_custom.png file.  You can view the png file using an appropriate viewer, such as 'display' if on a Linux/Unix host:
cd $WORKING_DIR
display wind_rose_custom.png

 

Your wind rose diagram will look like the following: