Modify openmc_find to return instance as well. Add C API docs

docs/source/capi/index.rst

@@ -4,15 +4,39 @@
 C API
 =====
 
-.. c:function:: int openmc_find(double* xyz, int rtype)
+.. c:function:: void openmc_calculate_voumes()
 
-   Return the ID of the cell/material containing a given point
+   Run a stochastic volume calculation
+
+.. c:function:: int openmc_cell_set_temperature(int id, double T)
+
+   Set the temperature of a cell.
+
+   :param id: ID of the cell
+   :type id: int
+   :param T: Temperature in Kelvin
+   :type T: double
+   :return: Return status (negative if an error occurred)
+   :rtype: int
+
+.. c:function:: void openmc_finalize()
+
+   Finalize a simulation
+
+.. c:function:: void openmc_find(double* xyz, int rtype, int* id, int* instance)
+
+   Determine the ID of the cell/material containing a given point
 
    :param xyz: Cartesian coordinates
    :type xyz: double[3]
    :param rtype: Which ID to return (1=cell, 2=material)
    :type rtype: int
-   :rtype: int
+   :param id: ID of the cell/material found. If a material is requested and the
+              point is in a void, the ID is 0. If an error occurs, the ID is -1.
+   :type id: int
+   :param instance: If a cell is repetaed in the geometry, the instance of the
+                    cell that was found and zero otherwise.
+   :type instance: int
 
 .. c:function:: void openmc_init(int intracomm)
 
@@ -21,9 +45,54 @@ C API
    :param intracomm: MPI intracommunicator
    :type intracomm: int
 
-.. c:function:: void openmc_finalize()
+.. c:function:: int openmc_load_nuclide(char name[])
 
-   Finalize a simulation
+   Load data for a nuclide from the HDF5 data library.
+
+   :param name: Name of the nuclide.
+   :type name: char[]
+   :return: Return status (negative if an error occurs)
+   :rtype: int
+
+.. c:function:: int openmc_material_add_nuclide(int id, char name[], double density)
+
+   Add a nuclide to an existing material. If the nuclide already exists, the
+   density is overwritten.
+
+   :param id: ID of the material
+   :type id: int
+   :param name: Name of the nuclide
+   :type name: char[]
+   :param density: Density in atom/b-cm
+   :type density: double
+   :return: Return status (negative if an error occurs)
+   :rtype: int
+
+.. c:function:: int openmc_material_get_densities(int id, double* ptr)
+
+   Get an array of nuclide densities for a material.
+
+   :param id: ID of the material
+   :type id: int
+   :param ptr: Pointer to the array of densities
+   :type ptr: double*
+   :return: Length of the array
+   :rtype: int
+
+.. c:function:: int openmc_material_set_density(int id, double density)
+
+   Set the density of a material.
+
+   :param id: ID of the material
+   :type id: int
+   :param density: Density of the material in atom/b-cm
+   :type density: double
+   :return: Return status (negative if an error occurs)
+   :rtype: int
+
+.. c:function:: void openmc_plot_geometry()
+
+   Run plotting mode.
 
 .. c:function:: void openmc_reset()
 
@@ -32,3 +101,36 @@ C API
 .. c:function:: void openmc_run()
 
    Run a simulation
+
+.. c:function:: int openmc_set_density(double xyz[3], double density)
+
+   Set the density of a material at a given point.
+
+   :param xyz: Cartesian coordinates
+   :type xyz: double[3]
+   :param density: Density of the material to set in atom/b-cm
+   :type density: double
+   :return: Return status (negative if an error occurs)
+   :rtype: int
+
+.. c:function:: int openmc_set_temperature(double xyz[3], double T)
+
+   Set the density of a cell at a given point.
+
+   :param xyz: Cartesian coordinates
+   :type xyz: double[3]
+   :param T: Temperature of the cell to set in Kelvin
+   :type T: double
+   :return: Return status (negative if an error occurs)
+   :rtype: int
+
+.. c:function:: void openmc_tally_results(int i, double** ptr, int shape_[3])
+
+   Get a pointer to tally results array.
+
+   :param i: Index in the tallies array
+   :type i: int
+   :param ptr: Pointer to the results array
+   :type ptr: double**
+   :param shape_: Shape of the results array
+   :type shape_: int[3]

docs/source/pythonapi/capi.rst

@@ -0,0 +1,10 @@
+---------------------------------------------------
+:data:`openmc.capi` -- Python bindings to the C API
+---------------------------------------------------
+
+.. autosummary::
+   :toctree: generated
+   :nosignatures:
+   :template: myclass.rst
+
+   openmc.capi.OpenMCLibrary

docs/source/pythonapi/index.rst

@@ -47,5 +47,6 @@ Modules
    mgxs
    model
    data
+   capi
    examples
    openmoc