**Block Inputs: **Scalar, vector, or matrix.

The -X block negates the input signal.

**1. Negation
of a scalar**

Consider the equation *y*(*t*)* =* -
sin(*t*), which can be realized as shown below.

A ramp block is used to access simulation time* t*, a
sin block generates sin(*t*), and a -X block converts sin(*t*) to
-sin(*t*). Both sin(*t*) and *y*(*t*) are plotted for
comparison.

**2. Negation
of a vector**

Consider the equation:

**z** = -**x**

where **x** = [-1 5.6 4]. This equation can
be realized as:

A scalarToVector block creates a three-element vector from the constant values -1, 5.6, and 4. When the simulation runs, the –X block performs an element-by-element negate operation on the incoming vector.

**3. Negation
of a matrix**

Consider the equation:

**Z** = -**X**

where

This equation can be realized as:

When the simulation runs, the –X block performs an element-by-element negate operation on the incoming matrix.