{
 "cells": [
  {
   "cell_type": "markdown",
   "metadata": {},
   "source": [
    "# Get grid\n",
    "\n",
    "The `get_grid` method returns an `xarray.Dataset` containing grid variables for a given model grid. It relies on a checkout of binary horizontal grid and topography files from the CESM [inputdata repository](https://svn-ccsm-inputdata.cgd.ucar.edu/trunk/inputdata). The vertical grid files are in the [POP2-CESM repository](https://github.com/escomp/pop2-cesm) in the `input_templates` directory; they are maintained separately as part of the `pop-tools` repository. \n"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": null,
   "metadata": {},
   "outputs": [],
   "source": [
    "%matplotlib inline\n",
    "import xarray as xr\n",
    "\n",
    "import pop_tools"
   ]
  },
  {
   "cell_type": "markdown",
   "metadata": {},
   "source": [
    "Get a dataset for the `POP_tx0.v3` tripole grid."
   ]
  },
  {
   "cell_type": "code",
   "execution_count": null,
   "metadata": {},
   "outputs": [],
   "source": [
    "ds = pop_tools.get_grid('POP_tx0.1v3')\n",
    "ds.info()"
   ]
  },
  {
   "cell_type": "markdown",
   "metadata": {},
   "source": [
    "## Visualize grid\n",
    "\n",
    "Take a quick look at `KMT` (`k` Index of Deepest Grid Cell on T Grid), applying a land-mask criterion along the way."
   ]
  },
  {
   "cell_type": "code",
   "execution_count": null,
   "metadata": {},
   "outputs": [],
   "source": [
    "h = ds.KMT.where(ds.KMT > 0).plot()"
   ]
  },
  {
   "cell_type": "markdown",
   "metadata": {},
   "source": [
    "And the coordinates: `TLAT`"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": null,
   "metadata": {},
   "outputs": [],
   "source": [
    "h = ds.TLAT.where(ds.KMT > 0).plot()"
   ]
  },
  {
   "cell_type": "markdown",
   "metadata": {},
   "source": [
    "and `TLONG`"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": null,
   "metadata": {},
   "outputs": [],
   "source": [
    "h = ds.TLONG.where(ds.KMT > 0).plot()"
   ]
  },
  {
   "cell_type": "markdown",
   "metadata": {},
   "source": [
    "## SCRIP format\n",
    "\n",
    "It is also possible to get the grid file in [SCRIP format](http://www.earthsystemmodeling.org/esmf_releases/public/last/ESMF_refdoc/node3.html#SECTION03028000000000000000) which is useful for regridding applications with ESMF."
   ]
  },
  {
   "cell_type": "code",
   "execution_count": null,
   "metadata": {},
   "outputs": [],
   "source": [
    "ds = pop_tools.get_grid('POP_tx0.1v3', scrip=True)\n",
    "ds.info()"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": null,
   "metadata": {},
   "outputs": [],
   "source": [
    "%load_ext watermark\n",
    "%watermark -d -iv -m -g"
   ]
  }
 ],
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