# PLaSK User Manual

#### Page Contents

- BandEdgesProviderCyl Class
  - `BandEdgesProviderCyl`
  - `BandEdgesProviderCyl.solver.outBandEdges()`
  - Methods
  - Descriptions
    - Method Details
      - `BandEdgesProviderCyl.__call__()`
      - `BandEdgesProviderCyl.set_changed()`

# BandEdgesProviderCyl Class

class plask.flow.BandEdgesProviderCyl(data)

  Provider of the conduction and valence band edges in Cylindrical geometry (eV).

  This class is used for conduction and valence band edges provider in binary solvers. You can also create a custom provider for your Python solver.

  Parameters:

    data – `Data` object to interpolate or callable returning it for given mesh. The callable must accept the same arguments as the provider `__call__` method (see below). It must also be able to give its length (i.e. have the `__len__` method defined) that gives the number of different provided values.

  To obtain the value from the provider simply call it. The call signature is as follows:

  solver.outBandEdges(n=0, mesh, interpolation='default')
    Parameters:

      - n (int) – Value number.

      - mesh (mesh) – Target mesh to get the field at.

      - interpolation (str) – Requested interpolation method.

    Returns:

      Data with the conduction and valence band edges on the specified mesh (eV).

  You may obtain the number of different values this provider can return by testing its length.

  Example

  Connect the provider to a receiver in some other solver:

      >>> other_solver.inBandEdges = solver.outBandEdges

  Obtain the provided field:

      >>> solver.outBandEdges(0, mesh)
      <plask.Data at 0x1234567>

  Test the number of provided values:

      >>> len(solver.outBandEdges)
      3

  See also

  Receiver of conduction and valence band edges: `plask.flow.BandEdgesReceiverCyl` Data filter for conduction and valence band edges: `plask.flow.BandEdgesFilterCyl`

## Methods

`__call__`(...) | Get value from the provider.
`set_changed`() | Inform all connected receivers that the provided value has changed.

## Descriptions

### Method Details

BandEdgesProviderCyl.__call__(n, mesh, interpolation='DEFAULT')
BandEdgesProviderCyl.__call__(mesh, interpolation='DEFAULT')

  Get value from the provider.

  Parameters:

    - n (int) – Value number.

    - mesh (mesh) – Target mesh to get the field at.

    - interpolation (str) – Requested interpolation method.

BandEdgesProviderCyl.set_changed()

  Inform all connected receivers that the provided value has changed.

  The receivers will have its changed attribute set to True and solvers will call the provider again if they need its value (otherwise they might take it from the cache.