主要内容

designmethods

从规范对象方法设计滤波器

描述

例子

方法= designmethods (designSpecs“SystemObject”,真的)返回可用的设计方法设计过滤系统过滤规范对象的对象,designSpecs

方法= designmethods (designSpecs“违约”)返回默认的过滤器规范对象的设计方法designSpecs

方法= designmethods (designSpecs,类型“SystemObject”,真的)返回类型滤波器设计方法规范对象,designSpecs类型可以是“杉”“信息检索”

方法= designmethods (designSpecs,‘满’,‘SystemObject’,真的)返回全名为每个可用的设计方法。例如,designmethods“全部”参数返回巴特沃斯黄油方法。

例子

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构造一个低通滤波器设计规范对象,确定有效的设计方法。

designSpecs = fdesign.lowpass (“Fp,置,美联社,Ast”60、500600、0.5、1 e4);方法= designmethods (designSpecs,“SystemObject”,真正的)
方法=8 x1细胞{“黄油”}{‘cheby1} {‘cheby2} {‘ellip} {‘equiripple} {‘ifir} {‘kaiserwin}{“多级”}

使用帮助获得更多的信息在切比雪夫型设计方法。

帮助(designSpecs方法{2})
设计一个切比雪夫型iir滤波器设计。高清=设计(D, cheby1)设计一个切比雪夫型过滤器D FDESIGN指定的对象,并返回DFILT / HD MFILT对象。高清=设计(D,…,“SystemObject”,true) implements the filter, HD, using a System object instead of a DFILT/MFILT object. HD = DESIGN(..., 'FilterStructure', STRUCTURE) returns a filter with the structure STRUCTURE. STRUCTURE is 'df2sos' by default and can be any of the following: 'df1sos' 'df2sos' 'df1tsos' 'df2tsos' 'cascadeallpass' 'cascadewdfallpass' Some of the listed structures may not be supported by System object filters. Type validstructures(D, 'cheby1', 'SystemObject', true) to get a list of structures supported by System objects. HD = DESIGN(..., 'MatchExactly', MATCH) designs a Chebyshev type I filter and matches the frequency and magnitude specification for the band MATCH exactly. The other band will exceed the specification. MATCH can be 'stopband' or 'passband' and is 'passband' by default. HD = DESIGN(..., 'SOSScaleNorm', NORM) designs an SOS filter and scales the coefficients using the P-Norm NORM. NORM can be either a discrete-time-domain norm or a frequency-domain norm. Valid time-domain norms are 'l1','l2', and 'linf'. Valid frequency-domain norms are 'L1','L2', and 'Linf'. Note that L2-norm is equal to l2-norm (Parseval's theorem) but the same is not true for other norms. The different norms can be ordered in terms of how stringent they are as follows: 'l1' >= 'Linf' >= 'L2' = 'l2' >= 'L1' >= 'linf'. Using the most stringent scaling, 'l1', the filter is the least prone to overflow, but also has the worst signal-to-noise ratio. Linf-scaling is the most commonly used scaling in practice. Scaling is turned off by default, which is equivalent to setting SOSScaleNorm = ''. HD = DESIGN(..., 'SOSScaleOpts', OPTS) designs an SOS filter and scales the coefficients using an FDOPTS.SOSSCALING object OPTS. Scaling options are: Property Default Description/Valid values --------- ------- ------------------------ 'sosReorder' 'auto' Reorder section prior to scaling. {'auto','none','up','down','lowpass', 'highpass','bandpass','bandstop'} 'MaxNumerator' 2 Maximum value for numerator coefficients 'NumeratorConstraint' 'none' {'none', 'unit', 'normalize','po2'} 'OverflowMode' 'wrap' {'wrap','saturate'} 'ScaleValueConstraint' 'unit' {'unit','none','po2'} 'MaxScaleValue' 'Not used' Maximum value for scale values When sosReorder is set to 'auto', the sections will be automatically reordered depending on the response type of the design (lowpass, highpass, etc.). Note that 'MaxScaleValue' will only be used when 'ScaleValueConstraint' is set to something other than 'unit'. If 'MaxScaleValue' is set to a number, the 'ScaleValueConstraint' will be changed to 'none'. Further, if SOSScaleNorm is off (as it is by default), then all the SOSScaleOpts will be ignored. For more information about P-Norm and scaling options see help for DFILT\SCALE. % Example #1 - Compare passband and stopband MatchExactly. h = fdesign.lowpass('Fp,Fst,Ap,Ast', .1, .3, 1, 60); Hd = design(h, 'cheby1', 'MatchExactly', 'passband'); Hd(2) = design(h, 'cheby1', 'MatchExactly', 'stopband'); % Compare the passband edges in FVTool. fvtool(Hd); axis([.09 .11 -2 0]);

输入参数

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过滤规范对象,指定为一个fdesign功能。

设计滤波器的脉冲响应,指定为“杉”“信息检索”。当没有指定,同时支持的输出函数设计方法万博1manbetx“杉”“信息检索”反应类型。

例子:designmethods (designSpecs,冷杉,SystemObject,真的)

输出参数

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可用的设计方法,作为细胞数组返回。每个单元格都包含方法的名称,是由参数输入功能。

版本历史

介绍了R2009a