span><span class="Operator">*</span><span class="Other">:</span> <span class="Identifier">cdouble</span>          <span class="Comment">## Relative step size for finite difference</span>
  <span class="Identifier">side</span><span class="Operator">*</span><span class="Other">:</span> <span class="Identifier">cint</span> <span class="Comment">## Sidedness of finite difference derivative</span>
              <span class="Comment">## 		        0 - one-sided derivative computed automatically</span>
            