designmethods

可用于从规范对象设计过滤器的方法

折叠所有页面

语法

方法= designmethods (designSpecs SystemObject,真的)

方法= designmethods (designSpecs“违约”)

方法= designmethods (designSpecs、类型SystemObject,真的)

方法= designmethods (designSpecs‘满’,‘SystemObject’,真的)

描述

例子

方法= designmethods (designSpecs“SystemObject”,真的)返回用于为过滤器规范对象设计过滤器系统对象的可用设计方法，designSpecs．

方法= designmethods (designSpecs“违约”)返回筛选器规范对象的默认设计方法designSpecs．

方法= designmethods (designSpecs，类型“SystemObject”,真的)返回类型过滤器规范对象的设计方法，designSpecs．类型可以是“杉”或“信息检索”．

方法= designmethods (designSpecs,‘满’,‘SystemObject’,真的)返回每个可用设计方法的全名。例如,designmethods与“全部”参数返回巴特沃斯为黄油方法。

例子

全部折叠

有效的低通滤波器设计方法

打开生活的脚本

构造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”}

使用帮助以获得更多关于Chebyshev I型设计方法的信息。

帮助(designSpecs方法{2})

设计一种切比雪夫型iir滤波器。HD = DESIGN(D， 'cheby1')设计一个由FDESIGN对象D指定的Chebyshev类型I过滤器，并返回DFILT/MFILT对象HD。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]);