Map Plotter

Map Plotter is a toolkit that provides a framework for 2D map plots of data and NetCDF files. It consists of a python class (MapPlotter) that interfaces with cartopy to generate beautiful maps.

This tool depends on:

• the PROJ library
• Cartopy
• the requests module

Two examples (example_MapPlotter_1.py and example_MapPlotter_2.py) are provided as a reference.

For any issues please contact: arnau.miro(at)upc(dot)edu.

Installation

A Makefile is provided within the tool to automate the installation for easiness of use for the user. To install the tool simply create a virtual environment as stated below or use the system Python. Once this is done simply type:

make

This will install all the requirements and install the package to your active python. To uninstall simply use

make uninstall

The previous operations can be done one step at a time using

make requirements

to install all the requirements and

make install

to install the tool.

Virtual environment

The package can be installed in a Python virtual environement to avoid messing with the system Python installation. Next, we will use Conda for this purpose. Assuming that Conda is already installed, we can create a virtual environment with a specific python version and name (my_env) using

conda create -n my_env python=3.8

The environment is placed in ~/.conda/envs/my_env. Next we activate it be able to install packages using conda itself or another Python package manager in the environment directory:

conda activate my_env

Then just follow the instructions as stated above.

Get cartopy

Cartopy can be installed using the pip tool by doing:

pip install cartopy

Sometimes a segmentation fault can appear when running some projections. In that case the following fixes the issue:

pip uninstall shapely
pip install --no-binary :all: shapely

Usage

The MAPPLOTTER class

Plot NETCDF data using CARTOPY. Example python snippets:

import MapPlotter as mp

# Define class instance
plotter = mp.MapPlotter(projection='PlateCarree')
params  = plotter.defaultParams() # Create basic parameters dictionary

# To plot already loaded fields
plotter.plot(lon,lat,data,params=params)

# To plot data from NetCDF data
plotter.plot_from_file(filename,varname,lonname,latname,iTime=0,iDepth=0,params=params)

# To see the data
plotter.save('outfile.png',dpi=300)
plotter.show() # wrapper of plt.show()

Command line tool

A command line tool is also provided so that maps can easily be generated from NetCDF files through the command prompt. It can be accessed as:

map_plotter [-h] -f FILE -v VAR [-m MASK] [--lon LON] [--lat LAT] 
			[-t TIME] [-d DEPTH] [-c CONF] -o OUT [--dpi DPI]

Arguments:

• -h, --help show this help message and exit
• -f FILE, --file FILE NetCDF file path
• -v VAR, --var VAR Variable to plot
• -m MASK, --mask MASK Mask file
• --lon LON Longitude variable name (default: glamt)
• --lat LAT Latitude variable name (default: gphit)
• -t TIME, --time TIME Time index for NetCDF (default: 0)
• -d DEPTH, --depth DEPTH Depth index for NetCDF (default: 0)
• -c CONF, --conf CONF Configuration file path
• -o OUT, --outfile OUT Output file name
• --dpi DPI Output file DPI (default: 300)