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SignalProcessing

  

BlackmanNuttallWindow

  

multiply an array of samples by a Blackman-Nuttall windowing function

 

Calling Sequence

Parameters

Options

Description

Thread Safety

Examples

Compatibility

Calling Sequence

BlackmanNuttallWindow(A)

Parameters

A

-

Array of real or complex numeric values; the signal

Options

• 

container : Array, predefined Array for holding results

• 

inplace : truefalse, specifies that output should overwrite input

Description

• 

The BlackmanNuttallWindow(A) command multiplies the Array A by the Blackman-Nuttall windowing function and returns the result in an Array having the same length.

• 

The Blackman-Nuttall windowing function wk is defined as follows for a sample with N points.

wk=0.36358190.4891775cos2kπn+0.1365995cos4kπn0.0106411cos6kπn

• 

Before the code performing the computation runs, A is converted to datatype float[8] or complex[8] if it does not have one of those datatypes already. For this reason, it is most efficient if A has one of these datatypes beforehand. This does not apply if inplace is true.

• 

If the container=C option is provided, then the results are put into C and C is returned. With this option, no additional memory is allocated to store the result. The container must be an Array of the same size and datatype as A.

• 

If the inplace or inplace=true option is provided, then A is overwritten with the results. In this case, the container option is ignored.

Thread Safety

• 

The SignalProcessing[BlackmanNuttallWindow] command is thread-safe as of Maple 18.

• 

For more information on thread safety, see index/threadsafe.

Examples

with( SignalProcessing ):

N := 1024:

a := GenerateUniform( N, -1, 1 );

_rtable18446884095782973678

(1)

BlackmanNuttallWindow( a );

_rtable18446884095637633614

(2)

c := Array( 1 .. N, 'datatype' = 'float'[ 8 ], 'order' = 'C_order' ):

BlackmanNuttallWindow( Array( 1 .. N, 'fill' = 1, 'datatype' = 'float'[ 8 ], 'order' = 'C_order' ), 'container' = c );

_rtable18446884095637621926

(3)

u := log~( FFT( c ) ):

use plots in display( Array( [ listplot( Re( u ) ), listplot( Im( u ) ) ] ) ) end;

 

Compatibility

• 

The SignalProcessing[BlackmanNuttallWindow] command was introduced in Maple 18.

• 

For more information on Maple 18 changes, see Updates in Maple 18.

See Also

SignalProcessing