From 96e9a74dd056a1ae7a741123359a5bcacdb93e62 Mon Sep 17 00:00:00 2001
From: chrishavlin <chris.havlin@gmail.com>
Date: Wed, 26 Jul 2023 15:06:57 -0500
Subject: [PATCH] add units example

---
 examples/ex_001_load_VBRc_structure.ipynb | 170 +++++++++++++++++++++-
 1 file changed, 169 insertions(+), 1 deletion(-)

diff --git a/examples/ex_001_load_VBRc_structure.ipynb b/examples/ex_001_load_VBRc_structure.ipynb
index d71cab4..7516e9f 100644
--- a/examples/ex_001_load_VBRc_structure.ipynb
+++ b/examples/ex_001_load_VBRc_structure.ipynb
@@ -53,7 +53,7 @@
      "name": "stderr",
      "output_type": "stream",
      "text": [
-      "pyVBRc : [INFO ] 2023-07-26 13:51:22,065:  /home/chavlin/src/vbrProjects/pyVBRc/pyVBRc/sample_data/VBRc_sample_LUT.mat loaded.\n"
+      "pyVBRc : [INFO ] 2023-07-26 15:06:33,017:  /home/chavlin/src/vbrProjects/pyVBRc/pyVBRc/sample_data/VBRc_sample_LUT.mat loaded.\n"
      ]
     }
    ],
@@ -216,6 +216,174 @@
     "plt.ylabel(\"Q$^{-1}$, andrade pseudo-period\")\n",
     "f.savefig('andrade_psp_T_dep.png')"
    ]
+  },
+  {
+   "cell_type": "markdown",
+   "id": "ecfac287-8cec-4d52-9707-4162cc782a0a",
+   "metadata": {},
+   "source": [
+    "## units\n",
+    "\n",
+    "When loading a `VBR` structure generated by newer versions of the `VBRc` (>=v1.0.0), the arrays that get loaded in will be `unyt` arrays:"
+   ]
+  },
+  {
+   "cell_type": "code",
+   "execution_count": 6,
+   "id": "054230e5-0392-4113-8652-917b94d847e9",
+   "metadata": {},
+   "outputs": [
+    {
+     "name": "stderr",
+     "output_type": "stream",
+     "text": [
+      "pyVBRc : [WARNING ] 2023-07-26 15:06:34,117:  Ch2o in SV has unsupported units (ppm), using nondimensional\n",
+      "pyVBRc : [INFO ] 2023-07-26 15:06:34,123:  /home/chavlin/src/vbrProjects/pyVBRc/pyVBRc/sample_data/VBRc_sample_LUT_v1pt0pt0.mat loaded.\n"
+     ]
+    }
+   ],
+   "source": [
+    "from pyVBRc.sample_data import get_sample_filename\n",
+    "from pyVBRc.vbrc_structure import VBRCstruct\n",
+    "\n",
+    "file = get_sample_filename(\"VBRc_sample_LUT_v1pt0pt0.mat\")\n",
+    "vbr = VBRCstruct(file)"
+   ]
+  },
+  {
+   "cell_type": "markdown",
+   "id": "ef18d5a0-7675-40ae-92a3-ea7020bcae72",
+   "metadata": {},
+   "source": [
+    "Inspecting the first 3 elements of the density array, for example:"
+   ]
+  },
+  {
+   "cell_type": "code",
+   "execution_count": 7,
+   "id": "e9025117-c7fb-4593-9e75-eda9066ec135",
+   "metadata": {},
+   "outputs": [
+    {
+     "data": {
+      "text/plain": [
+       "unyt_array([3300., 3300., 3300.], 'kg/m**3')"
+      ]
+     },
+     "execution_count": 7,
+     "metadata": {},
+     "output_type": "execute_result"
+    }
+   ],
+   "source": [
+    "vbr.input.SV.rho[1:4,0,0]"
+   ]
+  },
+  {
+   "cell_type": "markdown",
+   "id": "9bf3691c-3b1c-4b7b-a7ef-da48361f3fe6",
+   "metadata": {},
+   "source": [
+    "To change the units, "
+   ]
+  },
+  {
+   "cell_type": "code",
+   "execution_count": 8,
+   "id": "27ddb8ee-1f88-465c-af3f-3361a575122f",
+   "metadata": {},
+   "outputs": [
+    {
+     "data": {
+      "text/plain": [
+       "unyt_array([3.3, 3.3, 3.3], 'g/cm**3')"
+      ]
+     },
+     "execution_count": 8,
+     "metadata": {},
+     "output_type": "execute_result"
+    }
+   ],
+   "source": [
+    "vbr.input.SV.rho[1:4,0,0].to('g/cm**3')"
+   ]
+  },
+  {
+   "cell_type": "markdown",
+   "id": "4629c955-5e18-4827-b19b-3e420560b4e8",
+   "metadata": {},
+   "source": [
+    "`unyt` arrays will track and convert units throuhgout operations. For example, to calculate the hydrostaic pressure at 10 km depth for a single density value:"
+   ]
+  },
+  {
+   "cell_type": "code",
+   "execution_count": 9,
+   "id": "4cd341a9-21fd-4711-94b7-435144262b56",
+   "metadata": {},
+   "outputs": [],
+   "source": [
+    "from unyt import unyt_quantity, unyt_array "
+   ]
+  },
+  {
+   "cell_type": "code",
+   "execution_count": 10,
+   "id": "0d645a0d-d132-43d8-8a80-ccf199b1bd3d",
+   "metadata": {},
+   "outputs": [
+    {
+     "data": {
+      "text/plain": [
+       "unyt_quantity(3.234e+08, 'kg/(m*s**2)')"
+      ]
+     },
+     "execution_count": 10,
+     "metadata": {},
+     "output_type": "execute_result"
+    }
+   ],
+   "source": [
+    "P = vbr.input.SV.rho[1,0,0] * unyt_quantity(9.8, 'm/s**2') * unyt_quantity(10, 'km')\n",
+    "P"
+   ]
+  },
+  {
+   "cell_type": "code",
+   "execution_count": 11,
+   "id": "6623f460-2bf2-462c-ba87-bc58f3436d61",
+   "metadata": {},
+   "outputs": [
+    {
+     "data": {
+      "text/plain": [
+       "unyt_quantity(0.3234, 'GPa')"
+      ]
+     },
+     "execution_count": 11,
+     "metadata": {},
+     "output_type": "execute_result"
+    }
+   ],
+   "source": [
+    "P.to('GPa')"
+   ]
+  },
+  {
+   "cell_type": "markdown",
+   "id": "55079833-f25c-4901-b0cc-1cc0a118e29e",
+   "metadata": {},
+   "source": [
+    "check out the [full `unyt` docs](https://unyt.readthedocs.io/en/stable/) for more on working with `unyt` arrays and quantities"
+   ]
+  },
+  {
+   "cell_type": "code",
+   "execution_count": null,
+   "id": "1ebaa242-faae-4f48-91fc-cd8b0ec9f83c",
+   "metadata": {},
+   "outputs": [],
+   "source": []
   }
  ],
  "metadata": {