Corrects schematic of symmetric arrays

- The schematic of symmetric array with declaration/loop ranges
  was incorrect.
  - We realized this when explaining things in @septicscuzzy's office.
- Jupyter notebook used to create figures has been added but "empty" to save space.
- Figures appear on
  http://mom6.readthedocs.io/en/latest/api/generated/pages/Horizontal_indexing.html#declaration-of-variables

docs/images/Horizontal indexing in MOM6.ipynb

@@ -0,0 +1,128 @@
+{
+ "cells": [
+  {
+   "cell_type": "markdown",
+   "metadata": {},
+   "source": [
+    "### Generates schematics of horizontal indexing conventions"
+   ]
+  },
+  {
+   "cell_type": "code",
+   "execution_count": null,
+   "metadata": {
+    "collapsed": true
+   },
+   "outputs": [],
+   "source": [
+    "import numpy, matplotlib.pyplot as plt\n",
+    "%matplotlib inline\n",
+    "plt.xkcd();"
+   ]
+  },
+  {
+   "cell_type": "code",
+   "execution_count": null,
+   "metadata": {},
+   "outputs": [],
+   "source": [
+    "# Figure 1\n",
+    "def plot_grid(ni,nj,hi,hj,symmetric=True):\n",
+    "    isc,jsc,iec,jec = 0.5,0.5,ni-.5,nj-.5\n",
+    "    isd,jsd,ied,jed = isc-hi,jsc-hj,iec+hi,jec+hj\n",
+    "    if symmetric:\n",
+    "        IsdB,IedB,JsdB,JedB,IscB,IecB,JscB,JecB = isd-.5,ied+.5,jsd-.5,jed+.5,isc-.5,iec+.5,jsc-.5,jec+.5\n",
+    "    else:\n",
+    "        IsdB,IedB,JsdB,JedB,IscB,IecB,JscB,JecB = isd+.5,ied+.5,jsd+.5,jed+.5,isc+.5,iec+.5,jsc+.5,jec+.5\n",
+    "    #XsdB,XedB,YsdB,YedB = isd-.5,ied+.5,jsd-.5,jed+.5\n",
+    "    fig = plt.figure()\n",
+    "    ax1 = fig.add_subplot(111)\n",
+    "    ax2 = ax1.twiny()\n",
+    "    ax3 = ax1.twinx()\n",
+    "    for ax in [ax1,ax2,ax3]:\n",
+    "        ax.set_xlim(isd-1,ied+1)\n",
+    "        ax.set_ylim(jsd-1,ied+1)\n",
+    "    # Halos of data domain\n",
+    "    #for x in numpy.arange(IsdB,IedB+1): ax1.plot([x,x],[JsdB,JedB],'k')\n",
+    "    for x in numpy.arange(IsdB,IscB): ax1.plot([x,x],[jsd-.5,JedB],'b')\n",
+    "    for x in numpy.arange(IecB+1,IedB+1): ax1.plot([x,x],[jsd-.5,JedB],'b')\n",
+    "    for x in numpy.arange(IscB,IecB+1):\n",
+    "        ax1.plot([x,x],[jsd-.5,jsc-.5],'b')\n",
+    "        ax1.plot([x,x],[JecB,JedB],'b')\n",
+    "    #for y in numpy.arange(JsdB,JedB+1): ax1.plot([IsdB,IedB],[y,y],'k')\n",
+    "    for y in numpy.arange(JsdB,JscB): ax1.plot([isd-.5,IedB],[y,y],'b')\n",
+    "    for y in numpy.arange(JecB+1,JedB+1): ax1.plot([isd-.5,IedB],[y,y],'b')\n",
+    "    for y in numpy.arange(JscB,JecB+1):\n",
+    "        ax1.plot([isd-.5,isc-.5],[y,y],'b')\n",
+    "        ax1.plot([IecB,IedB],[y,y],'b')\n",
+    "    # Computational domain\n",
+    "    for x in numpy.arange(IscB,IecB+1): ax2.plot([x,x],[jsc-.5,jec+.5],'r')\n",
+    "    for y in numpy.arange(JscB,JecB+1): ax2.plot([isc-.5,iec+.5],[y,y],'r')\n",
+    "    for y in numpy.arange(jsd,jed+1):\n",
+    "        for x in numpy.arange(isd,ied+1):\n",
+    "            ax2.plot(x,y,'xb')\n",
+    "    for y in numpy.arange(jsc,jec+1):\n",
+    "        for x in numpy.arange(isc,iec+1):\n",
+    "            ax2.plot(x,y,'xr')\n",
+    "    for y in numpy.arange(JsdB,JedB+1):\n",
+    "        for x in numpy.arange(IsdB,IedB+1):\n",
+    "            ax2.plot(x,y,'ob')\n",
+    "    for y in numpy.arange(JscB,JecB+1):\n",
+    "        for x in numpy.arange(IscB,IecB+1):\n",
+    "            ax2.plot(x,y,'or')\n",
+    "    text_opts={'horizontalalignment':'center','verticalalignment':'center','backgroundcolor':'w'}\n",
+    "    ax1.set_xticks([IsdB,IscB,IecB,IedB])\n",
+    "    ax1.set_xticklabels(['IsdB','IscB','IecB','IedB'])\n",
+    "    ax1.set_yticks([JsdB,JscB,JecB,JedB])\n",
+    "    ax1.set_yticklabels(['JsdB','JscB','JecB','JedB'])\n",
+    "    ax1.set_xlabel('q-/u-point I')\n",
+    "    ax1.set_ylabel('q-/v-point J')\n",
+    "    ax2.set_xticks([isd,isc,iec,ied])\n",
+    "    ax2.set_xticklabels(['isd','isc','iec','ied'])\n",
+    "    ax2.set_xlabel('h-/v-point i')\n",
+    "    ax3.set_yticks([jsd,jsc,jec,jed])\n",
+    "    ax3.set_yticklabels(['jsd','jsc','jec','jed'])\n",
+    "    ax3.set_ylabel('h-/u-point j')\n",
+    "    for ax in [ax1,ax2,ax3]:\n",
+    "        ax.spines['bottom'].set_visible(False)\n",
+    "        ax.spines['top'].set_visible(False)\n",
+    "        ax.spines['left'].set_visible(False)\n",
+    "        ax.spines['right'].set_visible(False)\n",
+    "plot_grid(5,5,2,2,symmetric=False)\n",
+    "plt.savefig('Horizontal_NE_indexing_nonsym.png',bbox_inches='tight')"
+   ]
+  },
+  {
+   "cell_type": "code",
+   "execution_count": null,
+   "metadata": {},
+   "outputs": [],
+   "source": [
+    "plot_grid(5,5,2,2)\n",
+    "plt.savefig('Horizontal_NE_indexing_sym.png',bbox_inches='tight')"
+   ]
+  }
+ ],
+ "metadata": {
+  "anaconda-cloud": {},
+  "kernelspec": {
+   "display_name": "Python [default]",
+   "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": "3.5.3"
+  }
+ },
+ "nbformat": 4,
+ "nbformat_minor": 1
+}