<table class="params">
    <tr><td class="paramdir">[in]</td><td class="paramname">Ia</td><td>input three-phase coordinate <code>a</code> </td></tr>
    <tr><td class="paramdir">[in]</td><td class="paramname">Ib</td><td>input three-phase coordinate <code>b</code> </td></tr>
    <tr><td class="paramdir">[out]</td><td class="paramname">pIalpha</td><td>points to output two-phase orthogonal vector axis alpha </td></tr>
    <tr><td class="paramdir">[out]</td><td class="paramname">pIbeta</td><td>points to output 