multiply a sample by a Blackman windowing function - Maple Help

Online Help

All Products    Maple    MapleSim


Home : Support : Online Help : Science and Engineering : Signal Processing : Windowing Functions : SignalProcessing/BlackmanWindow

SignalProcessing[BlackmanWindow] - multiply a sample by a Blackman windowing function

Calling Sequence

BlackmanWindow( A, alpha )

Parameters

A

-

Array of real or complex numeric values; the signal

alpha

-

standard, optimal or a numeric value : (optional) parameter for Blackman windowing function

Description

• 

The BlackmanWindow( A, alpha ) command multiplies the Array A by the Blackman windowing function with parameter alpha and returns the result in an Array having the same length. The length of A must be at least 4.

• 

The Blackman windowing function w is defined as follows for a sample of N elements.

wk=α2+120.5cos2πkN1αcos4πnN12

• 

The default value of the parameter alpha is standard, and in this case, a value of alpha=0.16 is assumed. When alpha is optimal, then a value of alpha=0.51+cos2PiN1 is used. The alpha parameter may also take an arbitrary (real) numeric value.

• 

For an Array with complex values, the real and imaginary parts are multiplied by the same windowing function.

• 

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[BlackmanWindow] command is thread-safe as of Maple 17.

• 

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

Examples

withSignalProcessing:

a:=GenerateUniform10,1,1

a:=0.7852184921503080.5884139649570000.9931658226996680.9215782885439710.03878017095848920.01360579254105690.2107569728977980.7496002158150090.1389663578011100.212285134010017

(1)

BlackmanWindowa

2.1794191233668010-170.02993240224576700.2562372803328110.5805943217827020.03688497880109600.01294087563425600.1327768929256130.1933972316075260.007069167572588085.8920960890889510-18

(2)

BlackmanWindowa,'standard'

2.1794191233668010-170.02993240224576700.2562372803328110.5805943217827020.03688497880109600.01294087563425600.1327768929256130.1933972316075260.007069167572588085.8920960890889510-18

(3)

BlackmanWindowa,'optimal'

0.1.6331768297656010-170.1376472194880900.4954967621240610.03632646141536460.01274492312829700.1133158180526570.1038903907850343.8570912519772510-180.

(4)

c:=Array1..10,'datatype'='float'8,'order'='C_order':

BlackmanWindowa,'container'=c

2.1794191233668010-170.02993240224576700.2562372803328110.5805943217827020.03688497880109600.01294087563425600.1327768929256130.1933972316075260.007069167572588085.8920960890889510-18

(5)

c

2.1794191233668010-170.02993240224576700.2562372803328110.5805943217827020.03688497880109600.01294087563425600.1327768929256130.1933972316075260.007069167572588085.8920960890889510-18

(6)

a:=GenerateTone100,1,1π,π:

useplotsindisplayArraylistplota,listplotBlackmanWindowa,listplotBlackmanWindowa,'optimal';animatelistplot,'BlackmanWindow'a,α,α=1..1end use

See Also

SignalProcessing[BartlettWindow], SignalProcessing[HammingWindow], SignalProcessing[HannWindow], SignalProcessing[KaiserWindow]


Download Help Document

Was this information helpful?



Please add your Comment (Optional)
E-mail Address (Optional)
What is ? This question helps us to combat spam