Cheatography
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BU ENG EK 125 Matlab Cheat Sheet.
This is a draft cheat sheet. It is a work in progress and is not finished yet.
Basic
Help |
Exit |
Constants |
Format |
Type |
ML |
doc |
quit |
pi |
compact |
cast(b,'like',a) |
A=TP+TN/T |
help |
exit |
i |
loose |
char('a'+1)='b' |
P=TP/TP+FP |
demo |
|
j (=i) |
long (15 dp.) |
lookfor |
|
inf (∞) |
short (4 dp.) |
|
Randomizing
Real Numbers |
Integers |
Seeding |
rand: range 0-1 |
round(rand*N): range 0-N |
rng('shuffle'): sets clock as seed |
rand*N: range 0-N |
randi(n): range 1-n |
rng(intseed): introduces seed |
randi*(high-low)+low: range low-high |
randi([min,max]): range min-max |
rng('default'): default seed |
|
Numerical
Division |
Round |
Root |
Logs |
Degrees |
Sign |
rem(3,2)=1 |
fix |
sqrt |
log(x)=ln |
deg2rad |
sign(n)=1 if n>0 |
mod(3,2)=1 |
floor |
nthroot(64,3)=4 |
log2(x)=base 2 |
rad2deg |
sign(n)=0 if n=0 |
| |
ceil |
|
log10(x)=base 10 |
|
sign(n)=-1 if n<0 |
| |
round |
|
exp(n)=en |
|
Arrays
Creating |
Referring |
linspace(x,y,n): linear spacing, range x-y, n elem (def n=100) |
mat(n): nth element |
logspace(x,y,n): log spacing, range x-y, n elem (def n=50) |
length(vec): total elem in vec |
rand(n,m): n*m rand matrix |
[r, c]=size(mat): r=rows, c=columns |
randi([min,max],n,m): n*m int matrix |
length(math): r/c length (biggest) |
zeros(n,m): n*m matrix of 0 |
empty vec: [ ] |
ones(n,m): n*m matrix of 1 |
numel(mat): total elem in mat |
|
Misc Matrix
diff |
diff between consecutive vec |
dot |
dot product |
any |
if true for at least 1 elem |
cross |
cross product |
all |
if true for all elem |
diag |
returns diag of matrix |
find |
returns indices that meet criteria |
trace |
sum of elem in diag |
isequal |
compares arrays |
eye |
n*n identity matrix |
isdiag |
true if diag matrix |
issymmetric |
true if symmetric |
mean(data,'omitnan') |
ommits NaN to calc mean |
|
Plotting
Basic |
**Colors |
Markers |
plot(x,y,'r*')
axis([minx maxx miny maxy])
|
b: blue |
.: point |
^: up triangle |
xlabel, ylabel, title |
g: green |
o: circle |
<: left triangle |
bar, grid, scatter, corrcoef |
r: red |
x: x |
>: right triangle |
Lines |
c: cyan |
+: plus |
p: pentagram |
-: solid |
m: magenta |
*: star |
h: hexagram |
: : dotted |
y: yellow |
s: square |
|: vertical line |
-.: dash dot |
k: black |
d: diamond |
-: horizontal line |
—: dashed |
w: white |
v: down triangle |
|
Functions
function out = funcname(in)
%define for out
end
|
Basic user defined function, % for comments |
function [x,y,z] = fnname(a,b)
%print, plot, display
end
|
Calling with only 1 output var gives 1st value only |
function fnname(x,y)
%print, plot, display
end
|
Input args are not always needed (call fnname
or fnname()
) |
primary function header
body with sub function call
end
sub function header
body
end
|
Subfunction can only be called by name of the primary |
function outs = pers(x)
persistent runsum
if isempty(runsum)
runsum = 0;
end
runsum=runsum*x;
outsum=runsum;
end
|
Persistent variables |
function out = fnname(x)
persistent R
if isempty(R)
R=0;
end
out=R+x;
R=x;
end
|
Adds to previous |
function [x,y] = coor(theta)
x=1;
y=2;
end
|
Function stub |
|
Matrix Manipulation
reshape(mat,n,m) |
re-dimensions columnwise |
fliplr |
flips matrix left to right |
flipud |
flips matrix upside down |
rot90 |
rotates matrix counterclockwise 90° |
repmat(mat,n,m) |
replicates n*m copies of mat |
repelem(mat,n,m) |
replicates elements from mat n*m times |
cumsum/cumprod |
cumulative sum/product |
min(vec) |
minimum vector value |
max(vec) |
maximum vector value |
sum(vec) |
sum vector elements |
prod(vec) |
product vector elements |
abs(vec) |
absolute vector values |
|
