Defines a generic response. This is the same as the MSOLVE API Rv
element.

## Example

Assume that you want to determine the total energy required to drive a motion in a
revolute joint during a simulation. Assume that the joint is defined with an I
MARKER=22, and J MARKER=33. Here is how you would instantiate a response that
performs the desired calculation.

First, we begin by noting that the instantaneous power required to drive the motion
in a revolute joint is defined as:

(1)
$$\begin{array}{l}Instantaneous\text{}Power\text{}=\text{}|\left(Torque\text{}in\text{}Joint\right)*\left(Angular\text{}Velocity\text{}in\text{}Joint\right)|\\ \text{}=\text{}\underset{}{\overset{}{{\displaystyle \underset{{T}_{0}}{\overset{{T}_{f}}{\int}}(Instantaneous\text{}Power)\text{}dt}}}\\ \text{}=\text{}{\displaystyle \underset{{T}_{0}}{\overset{{T}_{f}}{\int}}(|Torque\text{}in\text{}Joint)*(Angular\text{}Velocity\text{}in\text{}Joint)|)dt}\end{array}$$

Now we can define the total energy expended in driving the motion as
follows:

```
>>> # Instantaneous torque and angular velocity in the revolute joint
>>> torque = “TZ(22,33,33)”
>>> wz = “WZ(22,33,33)”
>>>
>>> Instantaneous Power
>>> iPower = “ABS({torque}*{wz})”.format(torque=torque, wz=wz)
>>>
>>> #The total energy expended by the motion
>>> energy = GenericResponse (
label = "Total energy of Motion",
function = iPower
)
```

The calculations in GenericResponse are implemented as:

(2)
$$energy\text{}=\text{}{\displaystyle \underset{{T}_{0}}{\overset{{T}_{f}}{\int}}(|TZ(22,33,33)*WZ(22,33,33)|)}$$