blackman

Blackman windowing function.

Syntax

blackman(vec_expr)

Argument

vec_expr
A valid vector expression.

Example

Curve Math Vectors Result
x = c1.x

y = blackman(c1.y)

 Given c1, a curve is created which is the original curve windowed using the Blackman window function.

Comments

The Blackman function creates a vector using the Blackman-Harris windowing function.

The resultant vector is vec_expr multiplied by the Blackman-Harris window function. This function is given by:

Figure 1.


where w is the windowing function and N is the number of elements of vec_expr. Windowing functions are normally used in conduction with frequency operations. A Blackman windowing function is shown below.

Figure 2.


The resulting curve is power-normalized, in other words, the root mean square (RMS) of the original curve equals the RMS of the resulting curve. The mean is subtracted from the input before windowing in order to eliminate DC bias.