<choice>

A choice object represents a set of mutually exclusive options:

  <choice id="stats">
    <about>
      <label>Carrier Statistics</label>
      <description>Determines the model for carrier statistics used in bandgap narrowing calculations.</description>
    </about>

    <option>
      <about>
        <label>Boltzmann</label>
        <description>From the Boltzmann transport equation</description>
      </about>
      <value>bte</value>
    </option>

    <option>
      <about>
        <label>Fermi</label>
        <description>Fermi-Dirac statistics</description>
      </about>
    </option>

    <option>
      <about>
        <label>2D Gas</label>
        <description>Includes confinement at material interface</description>
      </about>
      <value>2deg</value>
    </option>
    <default>Boltzmann</default>
  </choice>

Each <option> has an <about> section with a label and an optional description. The label represents the option in the combobox, and the description appears in a tooltip that pops up when the option is currently selected.

Each <option> can also have a <value> used to represent it. The <value> for the selected option is passed along as the current value for the choice in the driver file passed to the underlying simulator. If there is no value, then the <label> is used instead. Either the <label> or the <value> can be used in the <default> specification to set the default choice.

You can see working code in the zoo of examples in the choice example or on the hub in the directory /apps/rappture/examples/zoo/choice.