# Module: Base

Simulation system size, and the size setup subroutine.

:Name: mod_mupro_base
:Depends on: None
:Defined variables: idp, rdp, cdp
:Defined types: [type_mupro_SizeContext](#type_mupro_SizeContext)
:Defined subroutines: [mupro_size_setup](#mupro_size_setup), [mupro_mpi_setup](#mupro_mpi_setup), [mupro_toml_read_file](#mupro_toml_read_file), [mupro_toml_get_value_evaluate](#mupro_toml_get_value_evaluate)

The module is to set commonly used double precision variable kind.

## Defined variables

```Fortran
    use, intrinsic :: ISO_Fortran_env
    integer, parameter::idp = int64
    integer, parameter::rdp = real64
    integer, parameter::cdp = real64
```

## Defined Types

### type_mupro_SizeContext

| Variable |  Type  | Meaning                                                         |
| :------: | :----: | :-------------------------------------------------------------- |
|    nx    | int32  | Number of simulation grids along x direction                    |
|    ny    | int32  | Number of simulation grids along y direction                    |
|    nz    | int32  | Number of simulation grids along z direction                    |
|    ns    | int32  | Number of simulation grids in the substrate for thin film setup |
|    nf    | int32  | Number of simulation grids in the film for thin film setup      |
|    lx    | real64 | Simulation size along x in real dimension (m)                   |
|    ly    | real64 | Simulation size along y in real dimension (m)                   |
|    lz    | real64 | Simulation size along z in real dimension (m)                   |

 <!--   |   kt   | int64                                                           | Number of simulation grids in the film for thin film setup | -->

<!-- |   dt0    | real64 | Simulation time step in reduced unit                            | -->

## Defined Subroutines

### mupro_size_setup(context)

Set the simulation size for the whole simulation, the variables will be used implicitly later in almost all the modules and subroutines.

```{important}
This is the base for all other modules. You must call the `mupro_size_setup` subroutine before you can use any other functionalities provided by the SDK.
```

| Argument |                      Type(Intent)                      | Meaning                                              |
| :------: | :----------------------------------------------------: | :--------------------------------------------------- |
| context  | [type_mupro_SizeContext(IN)](#type_mupro_SizeContext)  | The simulation size you want to have for the solvers |

### mupro_mpi_setup(rank, process)

Initialize the MPI, this is necessary for all simulation using our SDK.

```{important}
This is the base for all other modules. You must call the `mupro_mpi_setup` subroutine before you can use any other functionalities provided by the SDK. There is no particular sequence requested between mupro_mpi_setup and mupro_size_setup.
```

| Argument | Type(Intent)  | Meaning                                        |
| :------: | :-----------: | :--------------------------------------------- |
|   rank   | integer(out)  | The MPI rank for current core, starting from 0 |
| process  | integer(out)  | The total number of processes(cores)           |

### mupro_toml_read_file(file, table)

Read a toml file into toml_table type (from the toml-f package).

```{important}
You must use this subroutine before you and use the `get_value` and `mupro_toml_get_value_evaluate` subroutine to read parameters from the toml file.
```

| Argument |      Type(Intent)      | Meaning                                                     |
| :------: | :--------------------: | :---------------------------------------------------------- |
|   file   | character(len=\*)(in)  | The toml file name                                          |
|  table   |    toml_table(out)     | The toml_table to be used later in the get_value subroutine |

### mupro_toml_get_value_evaluate(table, name, out)

This subroutine combine the funtionalities of `get_value` from toml-f package, which can read a string from the toml file, and the `exprtk::expression`, `exprtk::parser` functions which evaluate string math expression into numbers.

| Argument |      Type(Intent)      | Meaning                                           |
| :------: | :--------------------: | :------------------------------------------------ |
|  table   |    toml_table(in)      | The toml_table obtained from mupro_toml_read_file |
|   name   | character(len=\*)(in)  | The key of the to be parsed toml variable         |
|   out    |  real(kind=rdp)(out)   | The exprtk evaluated number                       |