Detailed Description

A mathematical expression evaluation operator.

This CDP operator can be used to modify input value based on complex mathematical expressions with unlimited number of arguments.

Properties

Arguments

Evaluate operator arguments can be routed from another signal, parameter or property.

The power of the Evaluate operator

The Evaluate operator is a very powerful and flexible operator that can be used to do complex signal arithmetic without any C++ programming. Just add the named arguments to the Evaluate operator (values to the arguments can be routed from signals, properties or parameters) and specify the mathematical expression to calculate the output value. In every processing cycle this evaluation expression (that can refer to any of the named arguments in any combination) is used, and output value is calculated based on that.

Just to illustrate the power of Evaluate operator, below are examples how it can be used instead of many other, specialized CDP operators:

Example

Below is an example plot with Sine signal (cyan) and the same signal with Evaluate operator with property parameters:

Mathematical operators supported by Evaluate

Ternary Operator

Evaluate supports the "if then else" operator. It uses lazy evaluation in order to make sure only the necessary branch of the expression is evaluated.

Mathematical functions supported by Evaluate

When operator is used inside a signal its default input is automatically tied to signal's InternalValue or previous operator's output. Its default output is automatically tied to next operator's input or to signal's Value. See also CDP Operator Usage In CDP Signals.

Actual Processing Code of the Evaluate

unsigned int Evaluate<T>::Process()
{
  if (m->parserOk)
  {
    try
    {
      m->inputVal = static_cast<double>(m_input);
      for (size_t i=0; i < m_arguments.size(); i++)
        m->argVals[i] = static_cast<double>(*m_arguments[i]);
      m_output = m->mp.Eval();
    }
    catch (Parser::exception_type &e)
    {
      GetParent()->ReportConfigurationFault(this, "Can not evaluate expression '" + e.GetExpr() + "': " + e.GetMsg());
      m->faultReported = true;
      return STATUS_SIGNAL_FAULT;
    }
    if (m->faultReported)
    {
      GetParent()->ClearConfigurationFault(this);
      m->faultReported = false;
    }
    return STATUS_OK;
  }
  return STATUS_SIGNAL_FAULT;
}