diag_integral_init is the constructor for diag_integral_mod. </dd>
<dt>
<a href="#diag_integral_field_init">diag_integral_field_init</a>:</dt>
<dd>   diag_integral_field_init registers and intializes an integral field </dd>
<dt>
<a href="#sum_field_2d">sum_field_2d</a>:</dt>
<dd>   Perform a 2 dimensional summation of named field </dd>
<dt>
<a href="#sum_field_3d">sum_field_3d</a>:</dt>
<dd>   Perform a 3 dimensional summation of named field </dd>
<dt>
<a href="#sum_field_wght_3d">sum_field_wght_3d</a>:</dt