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info

Information about filter

Syntax

info(obj)
info(obj,'short')
info(obj,'long')
s = info(obj)

Description

info(obj) returns very basic information about the filter System object™, obj. The particulars depend on the filter type and structure.

info(obj,'short') returns the same information as info(obj).

info(obj,'long') returns the following information about the filter:

  • Specifications such as the filter structure and filter order

  • Information about the design method and options

  • Performance measurements for the filter response, such as the passband cutoff or stopband attenuation, included in the measure method

  • Cost of implementing the filter in terms of operations required to apply the filter to data, included in the cost method

When the filter uses fixed-point arithmetic, the function returns additional information about the filter, including the arithmetic setting and details about the filter internals.

s = info(obj) returns filter information in the variable s. You can also provide the optional arguments 'short' and 'long' with this syntax.

Input Arguments

obj

One of the following types of filter System objects:

The following Filter System objects are supported by this analysis function:

'short'

Input argument that instructs the function to return basic information about the filter.

'long'

Input argument that instructs the function to return in-depth information about the filter.

Output Arguments

s

Variable for storing filter information.

Examples

collapse all

Obtain short-format and long-format information about a filter.

d = fdesign.lowpass;
f = design(d,'SystemObject',true);
info(f)
ans =

  6×35 char array

    'Discrete-Time FIR Filter (real)    '
    '-------------------------------    '
    'Filter Structure  : Direct-Form FIR'
    'Filter Length     : 43             '
    'Stable            : Yes            '
    'Linear Phase      : Yes (Type 1)   '

info(f,'long')
ans =

  45×45 char array

    'Discrete-Time FIR Filter (real)              '
    '-------------------------------              '
    'Filter Structure  : Direct-Form FIR          '
    'Filter Length     : 43                       '
    'Stable            : Yes                      '
    'Linear Phase      : Yes (Type 1)             '
    '                                             '
    'Design Method Information                    '
    'Design Algorithm : equiripple                '
    '                                             '
    'Design Options                               '
    'Density Factor : 16                          '
    'Maximum Phase  : false                       '
    'Minimum Order  : any                         '
    'Minimum Phase  : false                       '
    'Stopband Decay : 0                           '
    'Stopband Shape : flat                        '
    'SystemObject   : true                        '
    'Uniform Grid   : true                        '
    '                                             '
    'Design Specifications                        '
    'Sample Rate     : N/A (normalized frequency) '
    'Response        : Lowpass                    '
    'Specification   : Fp,Fst,Ap,Ast              '
    'Stopband Atten. : 60 dB                      '
    'Passband Ripple : 1 dB                       '
    'Passband Edge   : 0.45                       '
    'Stopband Edge   : 0.55                       '
    '                                             '
    'Measurements                                 '
    'Sample Rate      : N/A (normalized frequency)'
    'Passband Edge    : 0.45                      '
    '3-dB Point       : 0.46957                   '
    '6-dB Point       : 0.48314                   '
    'Stopband Edge    : 0.55                      '
    'Passband Ripple  : 0.89042 dB                '
    'Stopband Atten.  : 60.945 dB                 '
    'Transition Width : 0.1                       '
    '                                             '
    'Implementation Cost                          '
    'Number of Multipliers            : 43        '
    'Number of Adders                 : 42        '
    'Number of States                 : 42        '
    'Multiplications per Input Sample : 43        '
    'Additions per Input Sample       : 42        '

See Also

Functions

Introduced in R2011a

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