Matlab ("MATrix LABoratory") je programovy system vyvinuty spolecnosti The MathWorks,Inc.
Tento strucny navod neni prekladem uzivatelskeho manualu k programu, snazi se pouze poslouzit studentum predmetu Linearni obvody a systemy pri zpracovani semestralni prace.
Matlab se nejdrive prosadil diky sve jednoduchosti vypoctu na
vysokych skolach, v poslednich letech se vsak stal standardem
softwarovych reseni v ruznych vyzkumnych oblastech.
Tento "chytry maticovy software" pracuje v podstate pouze s
jednim typem dat a tim je obdelnikova matice s realnymi nebo
komplexnimi prvky. Skalary potom vyjadrujeme
jako matice rozmeru (1 x 1) a vektory jako matice s jednim
radkem (1 x n) nebo jednim sloupcem (n x 1).
Vykonnost Matlabu je rozsirovana diky navazujicimu softwaru, ktery tvori predevsim soubory programu tzv. "toolboxy", orientovane zpravidla na dany problem nebo uzivatelem sestavene programy, tzv. m-files ( m-soubory).
Nyni uvedeme popis zakladnich funkci Matlabu.
Script soubor je tvoren posloupnosti prikazu Matlabu a
muze obsahovat i volani jinych
m-souboru nebo sam muze byt rekurzivni.
Je to textovy ASCII soubor, ktery vytvarime uzitim textoveho
editoru (Notepad, e-editor).
Uvedeny m-file spustime prikazem danym nazvem daneho souboru bez
pripony .m (>>buttord). Po skonceni vypoctu zustanou promenne
ulozeny v pracovni pameti.
Znak % indikuje komentar v textu.
Funkcni soubor je v v prvni radce m-souboru uveden slovem function. Promenne definovane a pouzivane uvnitr funkcniho souboru jsou lokalni a nemohou byt pouzivany globalne v pametovem souboru Matlabu ( jako promenne u script m-filu).
Manipulace s maticemi a vektory
Matlab pracuje s jedinym typem dat - obecne s obdelnikovou
komplexni matici.
B = | 1 | 2 | 3 |
1 | 2 | 3 | |
1 | 2 | 3 |
poly koeficienty charakteristickeho polynomu roots koreny polynomu (vlastni cisla) roots1 koreny polynomu jinou metodou polyval vypocet hodnot polynomu v urcitem intervalu polyvalm vypocet hodnot polynomu s matici conv konvoluce vektoru deconv zpetna konvoluce residue rozvoj na castecne zlomky polyfit aproximace vektoru polynomem
eps | = | 2-52 | presnost zobrazeni cisel |
pi | = | 3.1416 | Ludolfovo cislo |
Inf | = | 1/0 | reprezentace nekonecna |
NaN | = | Inf/Inf | neurcity vyraz nekonecno/nekonecno |
i = j | = | 0 + 1.0000j | imaginarni jednotka. |
+ | soucet | |
- | rozdil | |
* | soucin | (.*) |
/ | prave deleni | (./) |
\ | leve deleni | |
^ | mocnina | (.^) |
abs modul komplexniho cisla angle faze komplexniho cisla sqrt druha odmocnina real realna cast komplexniho cisla imag imaginarni cast komplexniho cisla conj komplexne sdruzene cislo round zaokrouhleni cisla fix odriznuti necele casti cisla floor dolni cela cast cisla ceil horni cela cast cisla sign znamenko cisla rem zbytek exp exponencialni funkce se zakladem e log prirozeny logaritmus log10 dekadicky logaritmus
sin cos tan asin arc sinus acos atan sinh sinus hyperbolicky cosh tanh asinh arc sinus hyperbolicky acosh atanh
plot zobrazi linearni graf x-y subplot rozcleneni graficke obrazovky na podgrafy semilogx zobrazi graf x-y, osa x logaritmicka semilogy zobrazi graf x-y, osa y logaritmicka loglog zobrazi graf x-y, obe osy logaritmicke polar graf v polarnich souradnicich mesh 3-rozmerny graf axis meritka os clg vymazani zobrazeneho grafuZobrazeny graf muzeme doplnit o popisy os, zahlavi, mrizku atd. pomoci prikazu
xlabel popis osy x ylabel popis osy y title zahlavi grafu text text v obrazku gtext text v obrazku umisteny mysi grid mrizkaExistuji 2 zpusoby zobrazeni nekolika zavislosti do jednoho grafu.
Typy car plna - carkovana _ teckovana : cerchovana -. Typy bodu bod . plus + hvezdicka * krouzek o krizek x Barvy car cervena 'r' zelena 'g' modra 'b' bila 'w' fialova 'm' neviditelna 'i'Napr. prikaz
Protoze cilem tohoto pomocnika neni zvladnuti Matlabu, ale pouze
napoveda pri reseni semestralni prace, uvedeme zde jeste dalsi
prikazy z ruznych toolboxu, ktere by studentum mohly reseni
usnadnit.
Vyvolanim helpu pro dany prikaz je mozne zjistit funkci daneho
prikazu i jeho syntaxi, pokud dany toolbox, ve kterem se prikaz nachazi,
je nainstalovan.
matlab\matfun - Matrix functions - numerical linear algebra. matlab\plotxy - Two dimensional graphics. toolbox\signal - Signal Processing Toolbox. toolbox\symbolic - Symbolic Math Toolbox.
abs - Magnitude. angle - Phase angle. conv - Convolution. filter - Filter implementation. filtfilt - Zero-phase version of filter. filtic - Determine filter initial conditions. freqs - Laplace transform frequency response. freqz - Z-transform frequency response. grpdelay - Group delay. impz - Impulse response (discrete). unwrap - Unwrap phase. zplane - Discrete pole-zero plot.
besself - Bessel analog filter design. butter - Butterworth filter design. cheby1 - Chebyshev type I filter design. cheby2 - Chebyshev type II filter design. ellip - Elliptic filter design.
buttord - Butterworth filter order selection. cheb1ord - Chebyshev type I filter order selection. cheb2ord - Chebyshev type II filter order selection. ellipord - Elliptic filter order selection.
invfreqs - Analog filter fit to frequency response. invfreqz - Discrete filter fit to frequency response. levinson - Levinson-Durbin recursion. lpc - Linear Predictive Coefficients using autocorrelation method. prony - Prony's discrete filter fit to time response. stmcb - Steiglitz-McBride iteration for ARMA modeling. ident - See also the Identification Toolbox.
besselap - Bessel filter prototype. buttap - Butterworth filter prototype. cheb1ap - Chebyshev type I filter prototype (passband ripple). cheb2ap - Chebyshev ty[pe II filter prototype (stopband ripple). ellipap - Elliptic filter prototype.
lp2bp - Lowpass to bandpass analog filter transformation. lp2bs - Lowpass to bandstop analog filter transformation. lp2hp - Lowpass to highpass analog filter transformation. lp2lp - Lowpass to lowpass analog filter transformation.
bilinear - Bilinear transformation with optional prewarping. impinvar - Impulse invariance analog to digital conversion.
plot - Linear plot. loglog - Log-log scale plot. semilogx - Semi-log scale plot. semilogy - Semi-log scale plot.
polar - Polar coordinate plot. bar - Bar graph. stem - Discrete sequence or "stem" plot. stairs - Stairstep plot. errorbar - Error bar plot. hist - Histogram plot. rose - Angle histogram plot. compass - Compass plot. fplot - Plot function.
title - Graph title. xlabel - X-axis label. ylabel - Y-axis label. text - Text annotation. gtext - Mouse placement of text. grid - Grid lines.
inverse - Symbolic matrix inverse. determ - Symbolic matrix determinant. linsolve - Solve simultaneous linear equations. nullspace - Basis for null space. colspace - Basis for column space. eigensys - Symbolic eigenvalues and eigenvectors. transpose - Symbolic matrix transpose. charpoly - Symbolic characteristic polynomial. jordan - Jordan canonical form. singvals - Symbolic singular values and singular vectors.
simplify - Simplify. expand - Expand. factor - Factor. collect - Collect. simple - Search for shortest form. allvalues - Find all values for RootOf expression. symsum - Symbolic summation.
solve - Symbolic solution of algebraic equations. dsolve - Symbolic solution of differential equations. finverse - Functional inverse. compose - Functional composition.
numeric - Convert symbolic matrix to numeric form. sym - Create or modify symbolic matrix. symvar - Determine symbolic variables. symop - Symbolic operations. symadd - Add symbolic expressions. symsub - Subtract symbolic expressions. symmul - Multiply symbolic expressions. symdiv - Divide symbolic expressions. sympow - Power of symbolic expression. symsize - Size of symbolic matrix. subs - Substitute for subexpression. numden - Numerator and denominator. poly2sym - Coefficient vector to symbolic polynomial. sym2poly - Symbolic polynomial to coefficient vector.