www.gusucode.com > signal 工具箱matlab源码程序 > signal/filt2block.m
function filt2block(b,varargin)
%FILT2BLOCK Generate Simulink filter block
%
% FILT2BLOCK(B) generates a Discrete FIR Filter block with filter
% coefficients B.
%
% FILT2BLOCK(B,'subsystem') generates a Simulink subsystem block that
% implements FIR filter B using sum, gain, and delay blocks.
%
% FILT2BLOCK(B,...,'FilterStructure',STRUCT) specify the filter
% structure, STRUCT, as one of 'directForm' | 'directFormTransposed' |
% 'directFormSymmetric' | 'directFormAntiSymmetric' | 'overlapAdd'. The
% default is 'directForm'. 'overlapAdd' is only valid when you omit the
% 'subsystem' flag (*).
%
% FILT2BLOCK(B,A) generates a Discrete Filter block with numerator B and
% denominator A.
%
% FILT2BLOCK(B,A,'subsystem') generates a Simulink subsystem block that
% implements IIR filter numerator B and denominator A using sum, gain,
% and delay blocks.
%
% FILT2BLOCK(B,A,...,'FilterStructure',STRUCT) specify the filter
% structure, STRUCT, as one of 'directForm1' | 'directForm1Transposed' |
% 'directForm2' | 'directForm2Transposed'. The default is 'directForm2'.
%
% FILT2BLOCK(SOS) generates a Biquad Filter block with second order
% sections matrix SOS. SOS is a Kx6 matrix, where the number of sections,
% K, must be greater than or equal to 2. (*)
%
% FILT2BLOCK(SOS,'subsystem') generates a Simulink subsystem block that
% implements biquad filter SOS using sum, gain, and delay blocks.
%
% FILT2BLOCK(SOS,...,'FilterStructure',STRUCT) specify the filter
% structure, STRUCT, as one of 'directForm1' | 'directForm1Transposed' |
% 'directForm2' | 'directForm2Transposed'. The default is
% 'directForm2Transposed'.
%
% FILT2BLOCK(D) generates a filter block with coefficients equal to
% those available in the digital filter, D. You design a digital filter,
% D, by calling the <a href="matlab:help designfilt">designfilt</a> function.
% A Discrete FIR Filter block is generated when D is an FIR filter. A
% Biquad Filter block is generated when D is an IIR filter (*).
%
% FILT2BLOCK(D,'subsystem') generates a Simulink subsystem block that
% implements the digital filter, D, using sum, gain, and delay blocks.
%
% FILT2BLOCK(D,...,'FilterStructure',STRUCT) for FIR filters, specify
% the filter structure, STRUCT, as one of 'directForm' |
% 'directFormTransposed' | 'directFormSymmetric' |
% 'directFormAntiSymmetric' | 'overlapAdd'. The default is
% 'directForm'. 'overlapAdd' is only valid when you omit the
% 'subsystem' flag (*).
% For IIR filters, specify the filter structure, STRUCT, as one of
% 'directForm1' | 'directForm1Transposed' | 'directForm2' |
% 'directForm2Transposed'. The default is 'directForm2Transposed'.
%
% (*) A DSP System Toolbox license is required for this syntax.
%
% FILT2BLOCK(..., PARAMETER1, VALUE1, PARAMETER2, VALUE2, ...) customizes
% the block with the following options:
%
% ----------------------- -------------- -----------------------------
% Parameter Value Description
% ----------------------- -------------- -----------------------------
% 'Destination' [{'current'} Specify whether you want to
% 'new' add the block to your current
% <user-defined Simulink model, create a new
% string>] model to contain the block,
% or specify the name of the
% target subsystem.
%
% 'BlockName' <string> Specify the name for the new
% block. By default the block
% is named 'filter'.
%
% 'OverwriteBlock' [true {false}] Specify if you want to
% overwrite an existing block
% with the same name as
% specified by the 'BlockName'
% parameter or create a new
% block.
%
% 'MapCoefficientsToPorts' [true {false}] Specify if you want to map
% the filter coefficients to
% the ports of the block.
%
% 'CoefficientNames' <cell-array> Specify the coefficient
% variable names as a cell
% array of strings.
% 'MapCoefficientsToPorts' must
% be true for this property to
% apply. The default is {'Num'}
% for FIR filters,
% {'Num','Den'} for IIR
% filters, and {'Num','Den','g'}
% for biquad filters.
%
% 'FrameBasedProcessing' [{true} false] Specify if you want the block
% to have frame-based or
% sample-based input processing.
%
% 'OptimizeZeros' [{true} false] Specify if you want to remove
% zero-gain blocks.
% This parameter is only valid
% when you input the 'subsystem'
% flag.
%
% 'OptimizeOnes' [{true} false] Specify if you want to replace
% unity-gainblocks with direct
% connections.
% This parameter is only valid
% when you input the 'subsystem'
% flag.
%
% 'OptimizeNegativeOnes' [{true} false] Specify if you want to replace
% negative unity-gain blocks
% with a sign change at the
% nearest sum block.
% This parameter is only valid
% when you input the 'subsystem'
% flag.
%
% 'OptimizeDelayChains' [{true} false] Specify if you want to replace
% cascaded chains of delay with
% an equivalent single integer
% delay block.
% This parameter is only valid
% when you input the 'subsystem'
% flag.
%
% % Example 1:
% % Generate a Discrete Filter block from IIR coefficients. Set the
% % name of the block to 'Lowpass IIR'.
%
% [B, A] = butter(6,0.4);
% filt2block(B,A,'BlockName','Lowpass IIR')
%
% % Example 2:
% % Generate a Simulink subsystem block that implements an FIR lowpass
% % filter using sum, gain, and delay blocks. Specify the input
% % processing to be elements as channels by setting the
% % 'FrameBasedProcessing' parameter to false.
%
% B = fir1(30,.25);
% filt2block(B,'subsystem','BlockName','Lowpass FIR',...
% 'FrameBasedProcessing',false)
% Copyright 2012-2013 The MathWorks, Inc.
if all(size(b)>[1 1])
% Input is a matrix, check if it is a valid SOS matrix
if size(b,2) ~= 6
error(message('signal:signalanalysisbase:invalidinputsosmatrix'));
end
filtType = 'SOS';
else
if isempty(varargin) || ischar(varargin{1})
% Only numerator has been passed, so this is an FIR filter
filtType = 'FIR';
else
% B,A has been passed so this is a non-SOS IIR filter
a = varargin{1};
if all(size(a)>[1 1])
error(message('signal:signalanalysisbase:inputnotsupported'));
end
varargin(1) = [];
filtType = 'IIR';
end
end
% Look for the 'subsystem' flag, 'Optimize*' inputs, 'on', 'off' flags,
% boolean inputs, structure inputs, and input processing.
callBlock = true;
optimizeInputs = false;
filterStructInput = false;
removeInputsIdx = [];
if ~isempty(varargin)
for idx = 1:length(varargin)
if ischar(varargin{idx})
inputVal = lower(varargin{idx});
switch inputVal
case{'mapcoeffstoports','optimizenegones','coeffnames','inputprocessing'}
error(message('signal:signalanalysisbase:invalidParamName',varargin{idx}))
case{'optimizezeros','optimizeones','optimizedelaychains'}
optimizeInputs = true;
case 'optimizenegativeones'
optimizeInputs = true;
varargin{idx} = 'OptimizeNegOnes';
case 'mapcoefficientstoports'
varargin{idx} = 'MapCoeffsToPorts';
case 'coefficientnames'
varargin{idx} = 'CoeffNames';
case 'subsystem'
callBlock = false;
removeInputsIdx = [removeInputsIdx idx]; %#ok<*AGROW>
case 'filterstructure'
filterStructInput = true;
removeInputsIdx = [removeInputsIdx idx idx+1];
if length(varargin) >= idx + 1
filterStructureName = varargin{idx+1};
else
error(message('signal:signalanalysisbase:unspecifiedFiltStruct'));
end
case {'on','off'}
error(message('signal:signalanalysisbase:invalidOnOffInputs'))
case {'framebasedprocessing'}
if length(varargin) >= idx + 1
tempValue = varargin{idx+1};
if ~islogical(tempValue)
error(message('signal:signalanalysisbase:invalidInputProc'))
end
varargin{idx} = 'InputProcessing';
if tempValue
varargin{idx+1} = 'columnsaschannels';
else
varargin{idx+1} = 'elementsaschannels';
end
else
error(message('signal:signalanalysisbase:unspecifiedInputProc'));
end
end
elseif islogical(varargin{idx})
% Convert logical flags to 'on' or 'off'
if varargin{idx}
varargin{idx} = 'on';
else
varargin{idx} = 'off';
end
end
end
end
dfiltStructName = [];
if filterStructInput
dfiltStructName = convertStructName(filterStructureName,filtType);
end
switch filtType
case 'FIR'
if isempty(dfiltStructName)
dfiltStructName = 'dffir';
end
if strcmp(dfiltStructName,'fftfir') && ~isfdtbxinstalled
error(message('signal:signalanalysisbase:invalidFFTFIR'));
end
Hd = dfilt.(dfiltStructName)(double(b));
if strcmp(dfiltStructName,'fftfir')
% Make sure we pass a correct block length
Nfft = Hd.BlockLength+length(b)-1;
B_Nfft = 2^nextpow2(Nfft);
Hd.BlockLength = B_Nfft-length(b)+1;
end
case 'IIR'
if isempty(dfiltStructName)
dfiltStructName = 'df2';
end
Hd = dfilt.(dfiltStructName)(double(b),double(a));
case 'SOS'
if isempty(dfiltStructName)
dfiltStructName = 'df2tsos';
end
Hd = dfilt.(dfiltStructName)(double(b));
end
varargin(removeInputsIdx) = [];
if callBlock
if strcmp(filtType,'SOS') && ~isfdtbxinstalled
error(message('signal:signalanalysisbase:noDSTLicenceForSOSBlock'));
end
if optimizeInputs
% Optimize inputs are only valid for realizemdl calls
error(message('signal:signalanalysisbase:invalidOptimizeInputs'));
end
block(Hd,varargin{:});
else
if strcmp(dfiltStructName,'fftfir')
error(message('signal:signalanalysisbase:invalidFFTFIR'))
end
realizemdl(Hd,varargin{:})
end
%--------------------------------------------------------------------------
function dfiltStructName = convertStructName(structName,filtType)
switch lower(structName)
case 'directform'
if ~strcmp(filtType,'FIR')
error(message('signal:signalanalysisbase:invalidFiltStruct',structName,'IIR'));
end
dfiltStructName = 'dffir';
case 'directformtransposed'
if ~strcmp(filtType,'FIR')
error(message('signal:signalanalysisbase:invalidFiltStruct',structName,'IIR'));
end
dfiltStructName = 'dffirt';
case 'directformsymmetric'
if ~strcmp(filtType,'FIR')
error(message('signal:signalanalysisbase:invalidFiltStruct',structName,'IIR'));
end
dfiltStructName = 'dfsymfir';
case 'directformantisymmetric'
if ~strcmp(filtType,'FIR')
error(message('signal:signalanalysisbase:invalidFiltStruct',structName,'IIR'));
end
dfiltStructName = 'dfasymfir';
case 'overlapadd'
if ~strcmp(filtType,'FIR')
error(message('signal:signalanalysisbase:invalidFiltStruct',structName,'IIR'));
end
dfiltStructName = 'fftfir';
case 'directform1'
if strcmp(filtType,'FIR')
error(message('signal:signalanalysisbase:invalidFiltStruct',structName,'FIR'));
end
dfiltStructName = 'df1';
if strcmp(filtType,'SOS')
dfiltStructName = [dfiltStructName 'sos'];
end
case 'directform1transposed'
if strcmp(filtType,'FIR')
error(message('signal:signalanalysisbase:invalidFiltStruct',structName,'FIR'));
end
dfiltStructName = 'df1t';
if strcmp(filtType,'SOS')
dfiltStructName = [dfiltStructName 'sos'];
end
case 'directform2'
if strcmp(filtType,'FIR')
error(message('signal:signalanalysisbase:invalidFiltStruct',structName,'FIR'));
end
dfiltStructName = 'df2';
if strcmp(filtType,'SOS')
dfiltStructName = [dfiltStructName 'sos'];
end
case 'directform2transposed'
if strcmp(filtType,'FIR')
error(message('signal:signalanalysisbase:invalidFiltStruct',structName,'FIR'));
end
dfiltStructName = 'df2t';
if strcmp(filtType,'SOS')
dfiltStructName = [dfiltStructName 'sos'];
end
otherwise
error(message('signal:signalanalysisbase:invalidFiltStructAll',structName));
end