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    "# Converting conditions and pH scales\n",
    "\n",
    "*Based on **CO2SYSExample2.m** for MATLAB by Steven van Heuven.*\n",
    "\n",
    "A sample is measured in the lab to have a pH of 7.8 on the Total scale at 25 °C under atmospheric pressure.\n",
    "\n",
    "What would its pH have been in situ in the ocean: at 2 °C and 4000 dbar pressure (roughly 4000 m depth) on the Seawater scale?\n",
    "\n",
    "Additional properties:\n",
    "\n",
    "  * Alkalinity = 2400 μmol/kg\n",
    "  * Salinity = 35\n",
    "  * Total silicate = 50 μmol/kg\n",
    "  * Total phosphate = 50 μmol/kg\n",
    "  \n",
    "## Define conditions\n",
    "\n",
    "The first step is to define the input and output conditions that we want to use with PyCO2SYS.  In this case, we only need a single value for every variable:"
   ]
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  {
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   "execution_count": 1,
   "metadata": {},
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    {
     "name": "stdout",
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     "text": [
      "Conditions have been defined!\n"
     ]
    }
   ],
   "source": [
    "# Define input and output conditions\n",
    "kwargs = dict(\n",
    "    par1_type = 1,  # The first parameter supplied is of type \"1\", which means \"alkalinity\"\n",
    "    par1 = 2400,  # value of the first parameter\n",
    "    par2_type = 3,  # The second parameter supplied is of type \"3\", which means \"pH\"\n",
    "    par2 = 7.8,  # value of the second parameter\n",
    "    salinity = 35,  # Salinity of the sample\n",
    "    temperature = 25,  # Temperature at input conditions\n",
    "    temperature_out = 2,  # Temperature at output conditions\n",
    "    pressure = 0,  # Pressure    at input conditions\n",
    "    pressure_out = 4000,  # Pressure    at output conditions\n",
    "    total_silicate = 50,  # Concentration of silicate  in the sample (in umol/kg)\n",
    "    total_phosphate = 2,  # Concentration of phosphate in the sample (in umol/kg)\n",
    "    opt_pH_scale = 1,  # pH scale at which the input pH is reported (\"1\" means \"Total Scale\")\n",
    "    opt_k_carbonic = 4,  # Choice of H2CO3 and HCO3- dissociation constants K1 and K2 (\"4\" means \"Mehrbach refit\")\n",
    "    opt_k_bisulfate = 1,  # Choice of HSO4- dissociation constant KSO4 (\"1\" means \"Dickson\")\n",
    "    opt_total_borate = 1,  # Choice of boron:sal (\"1\" means \"Uppstrom\")\n",
    ")\n",
    "print('Conditions have been defined!')"
   ]
  },
  {
   "cell_type": "markdown",
   "metadata": {},
   "source": [
    "## Run PyCO2SYS\n",
    "\n",
    "Next, we run PyCO2SYS to solve the marine carbonate system under the input and output conditions and calculate related variables:"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": 2,
   "metadata": {},
   "outputs": [
    {
     "name": "stdout",
     "output_type": "stream",
     "text": [
      "The in situ pH on the Seawater scale was: 7.990\n"
     ]
    }
   ],
   "source": [
    "# Import PyCO2SYS\n",
    "import PyCO2SYS as pyco2\n",
    "\n",
    "# Run PyCO2SYS\n",
    "results = pyco2.sys(**kwargs)\n",
    "\n",
    "# Extract and print out the result\n",
    "pH_insitu_SWS = results['pH_sws_out']\n",
    "print('The in situ pH on the Seawater scale was: {:.3f}'.format(pH_insitu_SWS))"
   ]
  },
  {
   "cell_type": "markdown",
   "metadata": {},
   "source": [
    "See [the documentation](https://pyco2sys.readthedocs.io/en/latest/co2sys_nd/) for more detailed information about the arguments and results of PyCO2SYS."
   ]
  }
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