WaveWatch3-Explorer.ipynb

{
 "cells": [
  {
   "cell_type": "markdown",
   "metadata": {},
   "source": [
    "# The power of xarray and holoviz for visualizing model output\n",
    "See https://hvplot.holoviz.org/user_guide/Gridded_Data.html"
   ]
  },
  {
   "cell_type": "markdown",
   "metadata": {},
   "source": [
    "An OPeNDAP Data URL for Global Wave Forecast Data, from the [Unidata THREDDS Server](https://thredds.ucar.edu/thredds/idd/forecastModels.html):"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": null,
   "metadata": {},
   "outputs": [],
   "source": [
    "url = 'https://thredds.ucar.edu/thredds/dodsC/grib/NCEP/WW3/Global/Best'"
   ]
  },
  {
   "cell_type": "markdown",
   "metadata": {},
   "source": [
    "With just these two imports..."
   ]
  },
  {
   "cell_type": "code",
   "execution_count": null,
   "metadata": {},
   "outputs": [],
   "source": [
    "import xarray as xr\n",
    "import hvplot.xarray\n",
    "import panel"
   ]
  },
  {
   "cell_type": "markdown",
   "metadata": {},
   "source": [
    "We open the dataset..."
   ]
  },
  {
   "cell_type": "code",
   "execution_count": null,
   "metadata": {},
   "outputs": [],
   "source": [
    "ds = xr.open_dataset(url)"
   ]
  },
  {
   "cell_type": "markdown",
   "metadata": {},
   "source": [
    "Examine a variable..."
   ]
  },
  {
   "cell_type": "code",
   "execution_count": null,
   "metadata": {},
   "outputs": [],
   "source": [
    "ds.Significant_height_of_combined_wind_waves_and_swell_surface"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": null,
   "metadata": {},
   "outputs": [],
   "source": [
    "var = 'Significant_height_of_combined_wind_waves_and_swell_surface'"
   ]
  },
  {
   "cell_type": "markdown",
   "metadata": {},
   "source": [
    "#### Make a powerful interactive plot in one line!"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": null,
   "metadata": {},
   "outputs": [],
   "source": [
    "ds[var].hvplot(x='lon', y='lat', rasterize=True, tiles='OSM', geo=True, \n",
    "               frame_width=500, widget_location='bottom', cmap='turbo')"
   ]
  },
  {
   "cell_type": "markdown",
   "metadata": {},
   "source": [
    "#### Make a projected plot with coastlines and animation controls\n",
    "... and use Panel so it would be run as a web app outside of Jupyter"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": null,
   "metadata": {},
   "outputs": [],
   "source": [
    "import cartopy.crs as ccrs"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": null,
   "metadata": {},
   "outputs": [],
   "source": [
    "crs = ccrs.Orthographic(central_longitude=-70, central_latitude=30)"
   ]
  },
  {
   "cell_type": "markdown",
   "metadata": {},
   "source": [
    "Select only the last 42 steps so that the first step is close to the present time"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": null,
   "metadata": {},
   "outputs": [],
   "source": [
    "viz = ds.Significant_height_of_combined_wind_waves_and_swell_surface[-42:,:,:].hvplot(x='lon', y='lat', \n",
    "                            cmap='rainbow', rasterize=True, frame_width=500, projection=crs, coastline=True,\n",
    "                            widget_type='scrubber',  widget_location='bottom')"
   ]
  },
  {
   "cell_type": "markdown",
   "metadata": {},
   "source": [
    "We use Panel and `.servable()` to make the dashboard displayable outside the notebook."
   ]
  },
  {
   "cell_type": "code",
   "execution_count": null,
   "metadata": {},
   "outputs": [],
   "source": [
    "panel.Column(viz).servable('WaveWatch Significant Wave Height')"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": null,
   "metadata": {},
   "outputs": [],
   "source": []
  }
 ],
 "metadata": {
  "kernelspec": {
   "display_name": "Python 3 (ipykernel)",
   "language": "python",
   "name": "python3"
  },
  "language_info": {
   "codemirror_mode": {
    "name": "ipython",
    "version": 3
   },
   "file_extension": ".py",
   "mimetype": "text/x-python",
   "name": "python",
   "nbconvert_exporter": "python",
   "pygments_lexer": "ipython3",
   "version": "3.10.6"
  },
  "widgets": {
   "application/vnd.jupyter.widget-state+json": {
    "state": {},
    "version_major": 2,
    "version_minor": 0
   }
  }
 },
 "nbformat": 4,
 "nbformat_minor": 4
}