zp = 1; >> np = [1 0.3 1]; >> step(zp,np) >> roots(np) ans = -0.1500 + 0.9887i -0.1500 - 0.9887i >> poly(1 2) ??? poly(1 2) | Error: Unexpected MATLAB expression. >> help poly POLY Convert roots to polynomial. POLY(A), when A is an N by N matrix, is a row vector with N+1 elements which are the coefficients of the characteristic polynomial, DET(lambda*EYE(SIZE(A)) - A) . POLY(V), when V is a vector, is a vector whose elements are the coefficients of the polynomial whose roots are the elements of V . For vectors, ROOTS and POLY are inverse functions of each other, up to ordering, scaling, and roundoff error. ROOTS(POLY(1:20)) generates Wilkinson's famous example. Class support for inputs A,V: float: double, single See also roots, conv, residue, polyval. Overloaded methods: sym/poly Reference page in Help browser doc poly >> impulse(zp,np) >> impulse(zp,np) >> bode(zp,np) >> simulink Warning: Using a default value of 0.2 for maximum step size. The simulation step size will be equal to or less than this value. You can disable this diagnostic by setting 'Automatic solver parameter selection' diagnostic to 'none' in the Diagnostics page of the configuration parameters dialog. ### Starting Real-Time Workshop build procedure for model: untitled ### Real-Time Workshop build procedure for model: 'untitled' aborted due to an error. Warning: Using a default value of 0.2 for maximum step size. The simulation step size will be equal to or less than this value. You can disable this diagnostic by setting 'Automatic solver parameter selection' diagnostic to 'none' in the Diagnostics page of the configuration parameters dialog. >> help sigprocessing sigprocessing not found. Use the Help browser Search tab to search the documentation, or type "help help" for help command options, such as help for methods. >> help FIR1 FIR1 FIR filter design using the window method. B = FIR1(N,Wn) designs an N'th order lowpass FIR digital filter and returns the filter coefficients in length N+1 vector B. The cut-off frequency Wn must be between 0 < Wn < 1.0, with 1.0 corresponding to half the sample rate. The filter B is real and has linear phase. The normalized gain of the filter at Wn is -6 dB. B = FIR1(N,Wn,'high') designs an N'th order highpass filter. You can also use B = FIR1(N,Wn,'low') to design a lowpass filter. If Wn is a two-element vector, Wn = [W1 W2], FIR1 returns an order N bandpass filter with passband W1 < W < W2. You can also specify B = FIR1(N,Wn,'bandpass'). If Wn = [W1 W2], B = FIR1(N,Wn,'stop') will design a bandstop filter. If Wn is a multi-element vector, Wn = [W1 W2 W3 W4 W5 ... WN], FIR1 returns an order N multiband filter with bands 0 < W < W1, W1 < W < W2, ..., WN < W < 1. B = FIR1(N,Wn,'DC-1') makes the first band a passband. B = FIR1(N,Wn,'DC-0') makes the first band a stopband. B = FIR1(N,Wn,WIN) designs an N-th order FIR filter using the N+1 length vector WIN to window the impulse response. If empty or omitted, FIR1 uses a Hamming window of length N+1. For a complete list of available windows, see the help for the WINDOW function. KAISER and CHEBWIN can be specified with an optional trailing argument. For example, B = FIR1(N,Wn,kaiser(N+1,4)) uses a Kaiser window with beta=4. B = FIR1(N,Wn,'high',chebwin(N+1,R)) uses a Chebyshev window with R decibels of relative sidelobe attenuation. For filters with a gain other than zero at Fs/2, e.g., highpass and bandstop filters, N must be even. Otherwise, N will be incremented by one. In this case the window length should be specified as N+2. By default, the filter is scaled so the center of the first pass band has magnitude exactly one after windowing. Use a trailing 'noscale' argument to prevent this scaling, e.g. B = FIR1(N,Wn,'noscale'), B = FIR1(N,Wn,'high','noscale'), B = FIR1(N,Wn,wind,'noscale'). You can also specify the scaling explicitly, e.g. FIR1(N,Wn,'scale'), etc. See also kaiserord, fircls1, fir2, firls, fircls, cfirpm, firpm, freqz, filter, window. Reference page in Help browser doc fir1 >> dzp = FIR1(8,0.01) Warning: Could not find an exact (case-sensitive) match for 'FIR1'. C:\Programme\MATLAB\R2007b\toolbox\signal\signal\fir1.m is a case-insensitive match and will be used instead. You can improve the performance of your code by using exact name matches and we therefore recommend that you update your usage accordingly. Alternatively, you can disable this warning using warning('off','MATLAB:dispatcher:InexactMatch'). dzp = 0.0181 0.0488 0.1227 0.1967 0.2274 0.1967 0.1227 0.0488 0.0181 >> 0.0181*4 ans = 0.0724 >> /4 ??? /4 | Error: Unexpected MATLAB operator. >> 0.0181*3 ans = 0.0543 >> 0.0181+0.0488 ans = 0.0669 >> ans*2 ans = 0.1338 >> dnp=[1 0 0 0 0 0 0 0 0] dnp = 1 0 0 0 0 0 0 0 0 >> help dstep DSTEP Step response of discrete-time linear systems. DSTEP(A,B,C,D,IU) plots the response of the discrete system: x[n+1] = Ax[n] + Bu[n] y[n] = Cx[n] + Du[n] to a step applied to the single input IU. The number of points is determined automatically. DSTEP(NUM,DEN) plots the step response of the polynomial transfer function G(z) = NUM(z)/DEN(z) where NUM and DEN contain the polynomial coefficients in descending powers of z. DSTEP(A,B,C,D,IU,N) or DSTEP(NUM,DEN,N) uses the user-supplied number of points, N. When invoked with left hand arguments, [Y,X] = DSTEP(A,B,C,D,...) [Y,X] = DSTEP(NUM,DEN,...) returns the output and state time history in the matrices Y and X. No plot is drawn on the screen. Y has as many columns as there are outputs and X has as many columns as there are states. See also: step, impulse, initial, lsim. >> dstep(dzp,dnp) >> impulse(dzp,dnp) >> dimpulse(dzp,dnp) >> dbode(dzp,dnp,100) >> dlmwrite('zaekoef.dat', dzp, ',') >> D:\Workstud\s9judoef ??? D:\Workstud\s9judoef | Error: Unexpected MATLAB operator. >> dlmwrite('D:\Workstud\s9judoef\P2\zaekoef.dat', dzp, ',') >>