CommandDescription

absAbsolute value

ackerCompute the K matrix to place the poles of A-BK, see alsoplace

axisSet the scale of the current plot, see also plot, figure

bodeDraw the Bode plot, see also logspace,margin,nyquist1

c2dmContinuous system to discrete system

clfClear figure (use clg in Matlab 3.5)

convConvolution (useful for multiplying polynomials), see also deconv

ctrbThe controllability matrix, see alsoobsv

deconvDeconvolution and polynomial division, see also conv

detFind the determinant of a matrix

dimpulseImpulse response of discrete-time linear systems, see alsodstep

dlqrLinear-quadratic requlator design for discrete-time systems, see alsolqr

dlsimSimulation of discrete-time linear systems, see alsolsim

dstepStep response of discrete-time linear systems, see alsostairs

eigCompute the eigenvalues of a matrix

epsMatlab's numerical tolerance

feedbackFeedback connection of two systems.

figureCreate a new figure or redefine the current figure, see also subplot, axis

forFor, next loop

formatNumber format (significant digits, exponents)

functionCreates function m-files

gridDraw the grid lines on the current plot

gtextAdd a piece of text to the current plot, see also text

helpHELP!

holdHold the current graph, see also figure

ifConditionally execute statements

imagReturns the imaginary part of a complex number, see also real

impulseImpulse response of continuous-time linear systems, see alsostep,lsim,dlsim

inputPrompt for user input

invFind the inverse of a matrix

jgridGenerate grid lines of constant damping ratio (zeta) and settling time (sigma), see alsosgrid,sigrid,zgrid

legendGraph legend

lengthLength of a vector, see also size

linspaceReturns a linearly spaced vector

lnyquist1Produce a Nyquist plot on a logarithmic scale, see alsonyquist1

lognatural logarithm, also log10: common logarithm

loglogPlot using log-log scale, also semilogx/semilogy

logspaceReturns a logarithmically spaced vector

lqrLinear quadratic regulator design for continuous systems, see alsodlqr

lsimSimulate a linear system, see alsostep,impulse,dlsim.

marginReturns the gain margin, phase margin, and crossover frequencies, see alsobode

normNorm of a vector

nyquist1Draw the Nyquist plot, see alsolnyquist1. Note this command was written to replace the Matlab standard command nyquist to get more accurate Nyquist plots.

obsvThe observability matrix, see alsoctrb

onesReturns a vector or matrix of ones, see also zeros

placeCompute the K matrix to place the poles of A-BK, see alsoacker

plotDraw a plot, see also figure, axis, subplot.

polyReturns the characteristic polynomial

polyaddAdd two different polynomials

polyvalPolynomial evaluation

printPrint the current plot (to a printer or postscript file)

pzmapPole-zero map of linear systems

rankFind the number of linearly independent rows or columns of a matrix

realReturns the real part of a complex number, see also imag

rlocfindFind the value of k and the poles at the selected point

rlocusDraw the root locus

rootsFind the roots of a polynomial

rscaleFind the scale factor for a full-state feedback system

setSet(gca,'Xtick',xticks,'Ytick',yticks) to control the number and spacing of tick marks on the axes

seriesSeries interconnection of Linear time-independent systems

sgridGenerate grid lines of constant damping ratio (zeta) and natural frequency (Wn), see alsojgrid,sigrid,zgrid

sigridGenerate grid lines of constant settling time (sigma), see alsojgrid,sgrid,zgrid

sizeGives the dimension of a vector or matrix, see also length

sqrtSquare root

ssCreate state-space models or convert LTI model to state space, see alsotf

ss2tfState-space to transfer function representation, see alsotf2ss

ss2zpState-space to pole-zero representation, see alsozp2ss

stairsStairstep plot for discreste response, see alsodstep

stepPlot the step response, see alsoimpulse,lsim,dlsim.

subplotDivide the plot window up into pieces, see also plot, figure

textAdd a piece of text to the current plot, see also title, xlabel, ylabel, gtext

tfCreation of transfer functions or conversion to transfer function, see alsoss

tf2ssTransfer function to state-space representation, see alsoss2tf

tf2zpTransfer function to Pole-zero representation, see alsozp2tf

titleAdd a title to the current plot

wbwReturns the bandwidth frequency given the damping ratio and the rise or settling time.

xlabel/ylabelAdd a label to the horizontal/vertical axis of the current plot, see also title, text, gtext

zerosReturns a vector or matrix of zeros

zgridGenerates grid lines of constant damping ratio (zeta) and natural frequency (Wn), see alsosgrid,jgrid,sigrid

zp2ssPole-zero to state-space representation, see alsoss2zp

zp2tfPole-zero to transfer function representation, see alsotf2zp