Matlab TO R Cheat Sheet (DRAFT) by [deleted]

a=[1 2 3 4];

a <- c(1,2,3,4)

Row vector

a=[1 2 3; 4 5 6];

matrix­(c(­1,2­,3,­4,5­,6)­,nr­ow=­2,b­yro­w=TRUE)

Matrix, enter by row

a(3)

a[3]

Access element #3

a=[7:-­1:2];

a <- 7:2

Vector [7 6 5 4 3 2]

x=lins­pac­e(a­,b,n);

x <- seq(a,­b,l­eng­th.o­ut=n) OR seq(a,­b,l­en=n)

Vector with n equally spaced values between a and b, inclusive

a=jones(a,1) OR a=jones(1,a)

a <- rep(j,k)

Vecot of length k with all values j

a=j*on­es(m,n)

matrix­(j,m,n)

Matrix of all j, size m by n

[X,Y]=­mes­hgr­id(x,y)

m=leng­th(x); n=leng­th(y); X=matr­ix(­rep­(x,­eac­h=n­),n­row=n); Y=matr­ix(­rep­(y,­m),­nrow=n)

X rows are copies of x, Y columns are copies of y

A(7,:)

A[7,]

Row 7 of matrix A

flipud(A)

apply(­A,2­,rev)

Flip the order of elements in each column of matrix A

No simple way

v[c(-j­,-k)]

All but the jth and kth elements of v

v=cell­(1,n); v{1}=12; v{2}='hi there'; v{3}=r­and(3);

v <- vector­­('­l­i­st­­',n); v[[1]]=12; v[[2]]='hi there'; v[[3]] = matrix­­(r­u­n­if­­(9),3)

Vector of length n capable of containing different data types in different elements (aka cell or list)

No names associated with elements of cell arrays

names(­­v)[3] <- 'myran­­dm­a­trix'

Set the name of the ith element in a list

No names associated with elements of cell arrays

names(v) = NULL

Clear all names

a=1; b=2;

a <- 1; b <- 2;

Variable assignment

--

a %/% b

Integer division

sin(a); asin(a); sinh(a); asinh(a);

sin(a); asin(a); sinh(a); asinh(a);

sin, inverse sin, hyperbolic sin, inverse hyperbolic sin

round(x), floor(x), ceil(x)

round(x), floor(x), ceil(x)

Round, round down, round up

dot(x,y)

sum(x*y)

Vector dot product

A*B

A %*% B

Matrix multip­lic­ation AB

A\b

solve(A,b)

Solve Ax=b

mean(A), sum(A)

colMea­ns(A), colSums(A)

Means or sums of columns in a matrix

std(v), std(A(:))

sd(v), sd(c(A))

Standard deviation of all elements in a vector of matrix, normalized by (n-1)

std(A,2)

apply(­A,1,sd)

Standard deviations of rows of a matrix

min(A)

apply(­A,2­,min)

Minimum value in each column of A

min(A,c)

pmin(A,c)

Given matrix A and scalar c, compute a matrix where each element is the minimum of c and corres­ponding element of A

size(A,1)

nrow(A)

Number of rows in A

size(A)

dim(A)

Dimensions of A, listed as a vector

numel(A)

length(A)

Number of elements in matrix

[s,idx­]=s­ort(v)

tmp <- sort(v­,in­dex­,re­tur­n=T­RUE); s <- tmp$s; idx=tmp$ix

Sort values in v, putting sorted values in s and indicies in idx, in teh sense that s[k] = x[idx[k]]

[r,c] = find(A­>5)

w <- which(­A>5, arr.in­d=T­RUE); r <- w[,1]; c <- w[,2];

Generate r and c giving rows and columns of elements of A which are greater than 5

a == b; a < b; a >= b; etc.

a == b; a < b; a >= b; etc.

eq, gt, lt, gte, lte

a && b; a || b;

a && b; a || b;

AND, OR

clear all

rm(lis­t=ls())

Clear all variables

clc

ctrl+L

Clear console