Merge pull request NCAR#145 from jukent/julyexamples2

Julyexamples2

docs/examples.rst

@@ -24,3 +24,6 @@ Here are some examples of how to use geocat-viz.
    examples/set_tick_direction_spine_visibility.ipynb
    examples/add_right_hand_axis.ipynb
    examples/add_major_minor_ticks.ipynb
+   examples/find_local_extrema.ipynb
+   examples/plot_contour_labels.ipynb
+   examples/plot_extrema_labels.ipynb

docs/examples/find_local_extrema.ipynb

@@ -0,0 +1,98 @@
+{
+ "cells": [
+  {
+   "cell_type": "markdown",
+   "metadata": {},
+   "source": [
+    "# `find_local_extrema`\n",
+    "\n",
+    "This notebook is a simple example of the GeoCAT-viz function <a href=\"../user_api/generated/geocat.viz.util.find_local_extrema.html#geocat-viz.util.find_local_extrema\">find_local_extrema</a>."
+   ]
+  },
+  {
+   "cell_type": "code",
+   "execution_count": null,
+   "metadata": {},
+   "outputs": [],
+   "source": [
+    "import numpy as np\n",
+    "import xarray as xr\n",
+    "import matplotlib.pyplot as plt\n",
+    "\n",
+    "import geocat.viz as gv"
+   ]
+  },
+  {
+   "cell_type": "code",
+   "execution_count": null,
+   "metadata": {},
+   "outputs": [],
+   "source": [
+    "# Generate dummy data\n",
+    "data = [[1, 4, 5, 6, 8.2],\n",
+    "        [9, 8.4, 10, 10.6, 9.7],\n",
+    "        [4.4, 5, 0, 6.6, 1.4],\n",
+    "        [4.6, 5.2, 1.5, 7.6, 2.4]]\n",
+    "\n",
+    "# Convert data into type xarray.DataArray\n",
+    "data = xr.DataArray(data,\n",
+    "                    dims=[\"lat\", \"lon\"],\n",
+    "                    coords=dict(lat=np.arange(4), lon=np.arange(5)))"
+   ]
+  },
+  {
+   "cell_type": "code",
+   "execution_count": null,
+   "metadata": {},
+   "outputs": [],
+   "source": [
+    "# Plot:\n",
+    "\n",
+    "# Generate figure (set its size (width, height) in inches)\n",
+    "plt.figure(figsize=(9.5, 8))\n",
+    "\n",
+    "# Generate axes\n",
+    "ax = plt.axes()\n",
+    "\n",
+    "# Plot filled contour and contour lines\n",
+    "contours = ax.contourf(data)\n",
+    "\n",
+    "# Find local min/max extrema with GeoCAT-Viz find_local_extrema\n",
+    "lmin = gv.find_local_extrema(data, eType='Low')[0]\n",
+    "lmax = gv.find_local_extrema(data, eType='High')[0]\n",
+    "\n",
+    "# Plot labels for local extrema\n",
+    "min_value = data.data[lmin[1]][lmin[0]]\n",
+    "ax.text(lmin[0], lmin[1], str(min_value))\n",
+    "\n",
+    "max_value = data.data[lmax[1]][lmax[0]]\n",
+    "ax.text(lmax[0], lmax[1], str(max_value))\n",
+    "\n",
+    "# Show plot\n",
+    "plt.show();"
+   ]
+  }
+ ],
+ "metadata": {
+  "kernelspec": {
+   "display_name": "geocat_viz_build",
+   "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": "3.10.10"
+  },
+  "orig_nbformat": 4
+ },
+ "nbformat": 4,
+ "nbformat_minor": 2
+}

docs/examples/plot_contour_labels.ipynb

@@ -0,0 +1,125 @@
+{
+ "cells": [
+  {
+   "cell_type": "markdown",
+   "metadata": {},
+   "source": [
+    "# `plot_contour_labels`\n",
+    "\n",
+    "This notebook is a simple example of the GeoCAT-viz function <a href=\"../user_api/generated/geocat.viz.util.plot_contour_labels.html#geocat-viz.util.plot_contour_labels\">plot_contour_labels</a>."
+   ]
+  },
+  {
+   "cell_type": "code",
+   "execution_count": null,
+   "metadata": {},
+   "outputs": [],
+   "source": [
+    "# Import packages:\n",
+    "\n",
+    "import xarray as xr\n",
+    "import matplotlib.pyplot as plt\n",
+    "import cartopy.crs as ccrs\n",
+    "import cartopy.feature as cfeature\n",
+    "import numpy as np\n",
+    "\n",
+    "import geocat.datafiles as gdf\n",
+    "import geocat.viz as gv"
+   ]
+  },
+  {
+   "cell_type": "code",
+   "execution_count": null,
+   "metadata": {},
+   "outputs": [],
+   "source": [
+    "# Read in data:\n",
+    "\n",
+    "# Open a netCDF data file using xarray default engine and\n",
+    "# load the data into xarrays\n",
+    "ds = xr.open_dataset(gdf.get(\"netcdf_files/slp.1963.nc\"), decode_times=False)\n",
+    "\n",
+    "# Get data from the 24th timestep\n",
+    "pressure = ds.slp[24, :, :]\n",
+    "\n",
+    "# Translate short values to float values\n",
+    "pressure = pressure.astype('float64')\n",
+    "\n",
+    "# Convert Pa to hPa data\n",
+    "pressure = pressure * 0.01\n",
+    "\n",
+    "# Fix the artifact of not-shown-data around 0 and 360-degree longitudes\n",
+    "wrap_pressure = gv.xr_add_cyclic_longitudes(pressure, \"lon\")"
+   ]
+  },
+  {
+   "cell_type": "code",
+   "execution_count": null,
+   "metadata": {},
+   "outputs": [],
+   "source": [
+    "# Create plot\n",
+    "\n",
+    "# Set figure size\n",
+    "fig = plt.figure(figsize=(8, 8))\n",
+    "\n",
+    "# Set global axes with an orthographic projection\n",
+    "proj = ccrs.Orthographic(central_longitude=270, central_latitude=45)\n",
+    "ax = plt.axes(projection=proj)\n",
+    "ax.set_global()\n",
+    "\n",
+    "# Plot contour data\n",
+    "p = wrap_pressure.plot.contour(ax=ax,\n",
+    "                               transform=ccrs.PlateCarree(),\n",
+    "                               linewidths=0.5,\n",
+    "                               cmap='black',\n",
+    "                               add_labels=False)\n",
+    "\n",
+    "contour_label_locations = [(176.4, 34.63), (-150.46, 42.44), (-142.16, 28.5),\n",
+    "                        (-134.12, 16.32), (-108.9, 17.08), (-98.17, 15.6),\n",
+    "                        (-108.73, 42.19), (-111.25, 49.66), (-127.83, 41.93),\n",
+    "                        (-92.49, 25.64), (-77.29, 29.08), (-77.04, 16.42),\n",
+    "                        (-95.93, 57.59), (-156.05, 84.47), (-17.83, 82.52),\n",
+    "                        (-76.3, 41.99), (-48.89, 41.45), (-33.43, 37.55),\n",
+    "                        (-46.98, 17.17), (1.79, 63.67), (-58.78, 67.05),\n",
+    "                        (-44.78, 53.68), (-69.69, 53.71), (-78.02, 52.22),\n",
+    "                        (-16.91, 44.33), (-95.72, 35.17), (-102.69, 73.62)]\n",
+    "\n",
+    "# Plot Clabels\n",
+    "gv.plot_contour_labels(ax,\n",
+    "                       p,\n",
+    "                       ccrs.Geodetic(),\n",
+    "                       proj,\n",
+    "                       clabel_locations=contour_label_locations)\n",
+    "\n",
+    "\n",
+    "# Make layout tight\n",
+    "plt.tight_layout()\n",
+    "\n",
+    "plt.show();"
+   ]
+  }
+ ],
+ "metadata": {
+  "kernelspec": {
+   "display_name": "geocat_viz_build",
+   "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": "3.10.0"
+  },
+  "orig_nbformat": 4
+ },
+ "nbformat": 4,
+ "nbformat_minor": 2
+}

docs/examples/plot_extrema_labels.ipynb

@@ -0,0 +1,127 @@
+{
+ "cells": [
+  {
+   "cell_type": "markdown",
+   "metadata": {},
+   "source": [
+    "# `plot_extrema_labels`\n",
+    "\n",
+    "This notebook is a simple example of the GeoCAT-viz function <a href=\"../user_api/generated/geocat.viz.util.plot_extrema_labels.html#geocat-viz.util.plot_extrema_labels\">plot_extrema_labels</a>."
+   ]
+  },
+  {
+   "cell_type": "code",
+   "execution_count": null,
+   "metadata": {},
+   "outputs": [],
+   "source": [
+    "# Import packages:\n",
+    "\n",
+    "import xarray as xr\n",
+    "import cartopy.crs as ccrs\n",
+    "import cartopy.feature as cfeature\n",
+    "import numpy as np\n",
+    "import matplotlib.pyplot as plt\n",
+    "from matplotlib import colors\n",
+    "import matplotlib.ticker as mticker\n",
+    "\n",
+    "import geocat.datafiles as gdf\n",
+    "import geocat.viz as gv"
+   ]
+  },
+  {
+   "cell_type": "code",
+   "execution_count": null,
+   "metadata": {},
+   "outputs": [],
+   "source": [
+    "# Read in data:\n",
+    "\n",
+    "# Open a netCDF data file using xarray default engine and\n",
+    "# load the data into xarrays\n",
+    "ds = xr.open_dataset(gdf.get(\"netcdf_files/slp.1963.nc\"), decode_times=False)\n",
+    "\n",
+    "# Get data from the 21st timestep\n",
+    "pressure = ds.slp[21, :, :]\n",
+    "\n",
+    "# Translate float values to short values\n",
+    "pressure = pressure.astype('float32')\n",
+    "\n",
+    "# Convert Pa to hPa data\n",
+    "pressure = pressure * 0.01\n",
+    "\n",
+    "# Fix the artifact of not-shown-data around 0 and 360-degree longitudes\n",
+    "wrap_pressure = gv.xr_add_cyclic_longitudes(pressure, \"lon\")"
+   ]
+  },
+  {
+   "cell_type": "code",
+   "execution_count": null,
+   "metadata": {},
+   "outputs": [],
+   "source": [
+    "# Create plot\n",
+    "\n",
+    "# Set figure size\n",
+    "fig = plt.figure(figsize=(8, 8))\n",
+    "\n",
+    "# Set global axes with an orthographic projection\n",
+    "proj = ccrs.Orthographic(central_longitude=270, central_latitude=45)\n",
+    "ax = plt.axes(projection=proj)\n",
+    "ax.set_global()\n",
+    "\n",
+    "# Plot contour data\n",
+    "p = wrap_pressure.plot.contour(ax=ax,\n",
+    "                               transform=ccrs.PlateCarree(),\n",
+    "                               linewidths=0.3,\n",
+    "                               levels=30,\n",
+    "                               cmap='black',\n",
+    "                               add_labels=False)\n",
+    "\n",
+    "# low pressure contour levels- these will be plotted\n",
+    "# as a subscript to an 'L' symbol.\n",
+    "lowClevels = gv.find_local_extrema(pressure, lowVal=995, eType='Low')\n",
+    "highClevels = gv.find_local_extrema(pressure, highVal=1042, eType='High')\n",
+    "\n",
+    "# Label low and high contours\n",
+    "gv.plot_extrema_labels(wrap_pressure,\n",
+    "                       ccrs.Geodetic(),\n",
+    "                       proj,\n",
+    "                       label_locations=lowClevels,\n",
+    "                       label='L',\n",
+    "                       show_warnings=False)\n",
+    "gv.plot_extrema_labels(wrap_pressure,\n",
+    "                       ccrs.Geodetic(),\n",
+    "                       proj,\n",
+    "                       label_locations=highClevels,\n",
+    "                       label='H',\n",
+    "                       show_warnings=False)\n",
+    "\n",
+    "\n",
+    "plt.show();"
+   ]
+  }
+ ],
+ "metadata": {
+  "kernelspec": {
+   "display_name": "geocat_viz_build",
+   "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": "3.10.0"
+  },
+  "orig_nbformat": 4
+ },
+ "nbformat": 4,
+ "nbformat_minor": 2
+}

docs/gallery.yml

@@ -21,3 +21,15 @@
 - title: 'add_major_minor_ticks'
   path: examples/add_major_minor_ticks.ipynb
   thumbnail: _static/thumbnails/add_major_minor_ticks.png
+
+- title: 'find_local_extrema'
+  path: examples/find_local_extrema.ipynb
+  thumbnail: _static/thumbnails/find_local_extrema.png
+
+- title: 'plot_contour_labels'
+  path: examples/plot_contour_labels.ipynb
+  thumbnail: _static/thumbnails/plot_contour_labels.png
+
+- title: 'plot_extrema_labels'
+  path: examples/plot_extrema_labels.ipynb
+  thumbnail: _static/thumbnails/plot_extrema_labels.png