Quick reference for Matlab programming language.
- Matlab Reference
- Table of Contents
- Getting Help
- Arrays
- User Interaction
- Loops
- Conditional Statements
- Functions
- Plotting
- Control Systems
- Reference
help command % Where command is what to find help for.Arrays are indexed starting at 1, and referenced using parenthesis '()'.
x = [1 4 6 8 3 5] % A list of numbers
x = 1:10 % A range of numbers, start and end number included.
x = 1:0.1:5 % A range of numbers with a set increment.
x = linspace(a,b,c) % A set of c numbers, between b and c (inclusive).
A = zeros(3,2) % 3x2 matrix of ones.
B = ones(4) % 4x4 matrix of zeros
R = rand(3) % 3x3 matrix of random numbers between 0 and 1a = R(:,3) % All row column 3
b = R(2,:) % Row 2 all columns
c = R(2:3,[1 3]) % Rows 2 and 3, columns 1 and 3
d = x(2:end) % Single dimension from index 2 to end y = x.^2 % Element wise operation require a period.
C = inv(R) % Inverse of a square matrix.
D = det(R) % Determinant of a square matrix.
E = D` % Transpose matrix D.
F = isequal(E,D) % Check if two matrices are equal (0 or 1)
G = length(D) % Returns the length of the largest dimension.
H = size(E) % Return a vector of matrix dimension sizes (Rows,Columns..)
disp('Hello World') % Print a simple message.
disp(['joined' 'strings']) % Strings can be joined if square brackes are used.
fprintf('A float. %3.2f\n',4.335) % Formatted output.
int2str(123) % Convert integer to string.in = input('Enter a number') % Get input from user.for num = 1:10
disp(int2str(num));
for num = 1:10
disp(int2str(num*2));
end
endvari = 0
while vari < 10
disp(int2str(vari));
vari = vari + 1;
endnum = 5
if num < 2
disp('Num less than 7')
elseif num < 7
disp('Num less than 7')
else
disp('Num greater than all')
endnum = 3
switch num
case 1
disp('Num = 1')
case 2
disp('Num = 2')
case 3
disp('Num = 3')
otherwise
disp('Num is huge')
end1 | 0 % OR operator (True)
1 & 0 % AND operator (False)
1 < 0 % Less than (False)
0 < 1 % Greater than (False)
0 == 1 % Equal to (False)
An example function, located in a separate file.
% FILE: myfunc.m
% File name must be the same as function name.
% File needs to be located in the same directory as script, or located on path.
function [r1 r2] = myfunc(a,b,c) % Function takes 3 arguments and return 2 values.
r1 = a*b*c; % Colons used to supress output.
r2 = a+b+c; % Colons used to supress output.Call the function from the main script like so:
[r1 r2] = myfunc(1,2,3) % Perform the above operations on 1,2,3
x = 1:10 % Create an array
y = x.^2 % Square the array
z = x.^3 % Cube the array
figure % Make a new figure window
hold on % Freeze ploting so multiple line can be made.
plot(x,y) % Plot the first function
plot(x,z) % Plot the next function.
xlabel('x') % X-axis label.
xlabel('y') % Y-axis label.
title('A Title') % Plot title.
hold off % Plot everything.x = 1:10 % Create an array.
y = x.^2 % Square the array.
z = x.^3 % Cube the array.
figure % Make a new figure window.
plot(x,y) % Plot the first figure.
figure
plot(x,z) % Plot the second figure.Full list of line types on Mathworks website.
x = 1:10 % Create an array.
y = x.^2 % Square the array.
z = x.^3 % Cube the array.
figure % Make a new figure window.
hold on % Freeze ploting so multiple line can be made.
plot(x,y,'-') % Plot with a '-' line
plot(x,z,'+') % Plot with a '+' symbol
plot(x,z,':') % Plot with a dotted line.
hold offx = 1:10 % Create an array.
y = x.^2 % Square the array.
z = x.^3 % Cube the array.
figure % Make a new figure window
subplot(1,2,1) % 1x2 Subplot, position 1
plot(x,y) % Plot the first figure.
title('Plot 1') % Plot 1 title
subplot(1,2,2) % 1x2 Subplot, position 2
plot(x,z) % Plot the second figure.
title('Plot 2') % Plot 2 title% Method 1
numF1 = 24*[1,2,3];
denF1 = [1,0,4,0];
F1 = tf(numF1,denF1)
% Method 2
numF2 = poly([0 -2]);
denF2 = poly([-4 2 -5]);
F2 = tf(numF2, denF2)
% Method 3
s = tf('s');
F3 = s*(s + 2) / ((s+4) * (s-2) * (s+5))
Ts = s*(s + 2) / ((s+4)*(s-2)) % An arbritrary transfer function.
pole(Ts) % Find the poles of the transfer function.
zero(Ts) % Find the zeros of the transfer function.
pzmap(Ts) % Plot the poles and zeros in cartesian coordinates.G1s = tf([1],[2,3]) % Forward path transfer function one.
G2s = tf([1],[2,3]) % Forward path transfer function two.
H1 = tf([1],[1,0]) % Feedback path tranfer function.
Gfp = series(G1s,G2s) % Series combination, equivalent to G1s * G2s
Gfs = parallel(G1s,G2s) % Parallel combination, equivalent to G1s + G2s
Ts = feedback(G1s,H1,-1) % Combine feedback loop, integer represents positive/negitive.abs % Absolute value complex magnitude.
acos, acosh % Inverse cosine, inverse hyperbolic cosine.
acot, acoth % Inverse cotangent, inverse hyperbolic cotangent.
acsc, acsch % Inverse cosecant,inverse hyperbolic cosecant.
angle % Phase angle.
asec, asech % Inverse secant, inverse hyperbolic secant.
asin, asinh % Inverse sine, inverse hyperbolic sine.
atan, atanh % Inverse tangent, inverse hyperbolic tangent
atan2 % Four-quadrant inverse tangent.
ceil % Round toward infinity.
complex % Construct complex data from real and imaginary components.
conj % Complex conjugate.
cos, cosh % Cosine, hyperbolic cosine.
cot, coth % Cotangent, hyperbolic cotangent.
exp % The exponential.
fix % Round towards zero.
floor % Round towards minus infinity.
gcd % Greatest common divisor.
imag % Imaginary part of a complex number.
lcm % Least common multiple.
log % Natural logarithm.
log2 % Base 2 logarithm, dissect floating-point numbers.
log10 % Common (base 10) logarithm.
mod % Modulus.
nchoosek % Binomial coefficient or all combinations.
real % Real part of complex number.
rem % Remainder after division.
round % Round to nearest integer.
sec, sech % Secant, and hyperbolic secant.
sign % Signum function, get sign of number.
sin, sinh % Sine, hyperbolic sine.
sqrt % Square root.
tan, tanh % Tangent, hyperbolic tangent.corrcoef % Correlation coefficients.
cov % Covarient matrix.
cross % Vecotr cross product
cumprod % Cumulative product
cumsum % Cumulative sum
cumtrapz % Cumulative trapezoidal numerical integration
delaunay % Delaunay triangulation
del2 % Discrete Laplacian
diff % Differences and approximate derivatives
fdsearch % Search for nearest point
factor % Prime factors
gradient % Numerical gradient
histogram % Histogram or Bar chart
inpolygon % Detect points inside a polygonal region
max % Maximum elements of an array
mean % Average or mean value of arrays
median % Median value of arrays
min % Minimum elements of an array
perms % All possible permutations
polyarea % Area of polygon
primes % Generate list of prime numbers
prod % Product of array elements
rand % Uniformly distributed random number
randn % Normally distributed random number
sort % Sort elements in ascending order
sortrows % Sort rows in ascending order
std % Standard deviation
sum % Sum of array elements
trapz % Trapezoidal numerical integration
tsearch % Search for enclosing Delaunay triangle
var % Variance
voronoi % Voronoi diagramcalendar % Calendar.
clock % Current time as a date vector.
cputime % Elapsed CPU time.
date % Current date string.
datenum % Serial date number.
datestr % Date string format.
datevec % Date components.
eomday % End of month.
etime % Elapsed time.
now % Current date and time.
tic, toc % Stopwatch timer.
weekday % Day of the week.bar % Vertical bar chart.
barh % Horizontal bar chart.
hist % Plot histograms.
hold % Hold current graph.
loglog % Plot using log-log scales.
pie % Pie plot.
plot % Plot vectors or matrices..
polar % Polar coordinate plot.
semilogx % Semi-log scale plot (X).
semilogy % Semi-log sclale plot (Y).
subplot % Crease multiple plots in one.bar3h % Vertical 3-D bar chart.
comet3 % Horizontal 3-D bar chart.
cylinder % 3-D comet plot.
fill3 % Generate cylinder.
plot3 % Draw filled 3-D polygons in 3-space.
quiver3 % Plot lines and points in 3-D space.
slice % 3-D quiver (or velocity) plot.
sphere % Volumetric slice plot.
stem3 % Generate sphere.
waterfall % Plot discrete surface data.clabel % Add contour labels to a contour plot.
datetick % Date formatted tick labels.
grid % Grid lines for 2-D and 3-D plots.
gtext % Place text on a 2-D graph using a mouse.
legend % Graph legend for lines and patches.
plotyy % Plot graphs with Y tick labels on the left and right.
title % Titles for 2-D and 3-D plots.
xlabel % X-axis labels for 2-D and 3-D plots.
ylabel % Y-axis labels for 2-D and 3-D plots.
zlabel % Z-axis labels for 3-D plots.contour % Contour (level curves) plot.
contourc % Contour computation.
contourf % Filled contour plot.
hidden % Mesh hidden line removal mode.
meshc % Combination mesh/contourplot.
mesh % 3-D mesh with reference plane.
peaks % A sample function of two variables.
surf % 3-D shaded surface graph.
surface % Create surface low-level objects.
surfc % Combination surf/contourplot.
surfl % 3-D shaded surface with lighting.
trimesh % Triangular mesh plot.
trisurf % Triangular surface plot.griddata % Data gridding and surface fitting.
meshgrid % Generation of X and Y arrays for 3-D plots.
polyfit(x,y,n) % Finds the coefficients of a polynomial of degreen n with x and y.
interp1(x,Y,xi) % Returns vector elements corresponding to elements xi.
spline(x,y,xx) % Returns the f(xx) value at xx for interpolating cubic spline.polyval(p1,x) % Polynomical (p1), evaluated at x.
conv(u,v) % Convolution.
deconv(v,u) % Deconvolution.
roots(c) % Returns a columns vector for roots of polynominal.fft(xt) % Get the fast Fourier transform of x(t).
fftshift(xf) % Center a FFT about the zero frequency.
cheby2(A,B,C,D) % Get filter coeffecients for chebyshev filter.
filter(B,A,X) % Filter a time domain signal with filter coefficients.