<?xml version="1.0" encoding="UTF-8"?>
<simulation xmds-version="2">
  <name>tla</name>
  <author>Unknown</author>
  <description>
    Two level atom example simulation. Illustrates a cross-propagating field.
  </description>
  
  <features>
    <benchmark />
    <error_check />
    <bing />
    <fftw plan="patient" />
    <globals>
      <![CDATA[
      const real g = 1.0;
      const real t0 = 1.0;
      ]]>
    </globals>
  </features>
  
  <geometry>
    <propagation_dimension> z </propagation_dimension>
    <transverse_dimensions>
      <dimension name="t" lattice="10000"  domain="(-10, 15)" />
    </transverse_dimensions>
  </geometry>
  
  <vector name="main" initial_basis="t" type="real">
    <components>
      E
    </components>
    <initialisation>
      <![CDATA[
        E = 2/t0/cosh(t/t0);
      ]]>
    </initialisation>
  </vector>

  <vector name="cross" initial_basis="t" type="real">
    <components>
      P N
    </components>
    <initialisation>
      <![CDATA[
        P = 0.0;
        N = -1.0;
      ]]>
    </initialisation>
  </vector>
  
  <sequence>
    <integrate algorithm="RK4" interval="4" steps="200">
      <samples>100 100</samples>
      <operators>
        <operator kind="cross_propagation" algorithm="RK4" propagation_dimension="t">
          <integration_vectors>cross</integration_vectors>
          <!-- You can have a dependencies tag in here -->
          <dependencies>main</dependencies>
          <boundary_condition kind="left">
            <!-- You can also have a dependencies tag in here -->
            <!-- like the one shown below, but none are needed -->
            <!-- in this example -->
            <!-- <dependencies>cross</dependencies> -->
            <![CDATA[
              P = 0.0;
              N = -1.0;
            ]]>
          </boundary_condition>
          <![CDATA[
            dP_dt = E*N;
            dN_dt = -E*P;
          ]]>
        </operator>
        <integration_vectors>main</integration_vectors>
        <![CDATA[
          dE_dz = g*P;
        ]]>
      </operators>
    </integrate>
  </sequence>
  
  <output>
      <sampling_group basis="t(1000)" initial_sample="yes">
        <moments>pow_dens</moments>
        <dependencies>main</dependencies>
        <![CDATA[
          pow_dens = E*E;
        ]]>
      </sampling_group>
      <sampling_group basis="t(1000)" initial_sample="no">
        <moments>P_out N_out</moments>
        <dependencies>cross</dependencies>
        <![CDATA[
          P_out = P;
          N_out = N;
        ]]>
      </sampling_group>
  </output>
</simulation>