R-MATLAB-IGOR Cheat Sheet This is a short guide to translate commands in three different numerical analysis software packages: R, MATLAB and IGOR Pro. Equivalents are given for commands, gathered under a set of headings. This work is mainly by Vidar Bronken Gundersen and Ben Gallarda, see Credits for details.
If you can contribute to this cheat sheet (edits, corrections, more categories etc.), please use GitHub's fork/pull/propose changes facility . The fields with ? need attention.
Note that some commands use IGOR Pro 7 and are not compatible with IGOR Pro 6.3 or lower.
##Table of contents
Basics and Terminology Help Searching available documentation Using interactively Operators Arithmetic operators Relational operators Logical operators root and logarithm Round off Mathematical constants Missing values Complex numbers Trigonometry Generate random numbers Vectors Sequences Concatenation (vectors) Repeating Miss those elements out Maximum and minimum Vector multiplication Matrices Concatenation (matrices); rbind and cbind Array creation Reshape and flatten matrices Shared data (slicing) Indexing and accessing elements (Python: slicing) Assignment Transpose and inverse Sum Sorting Maximum and minimum Matrix manipulation Equivalents to “size” Matrix- and elementwise- multiplication Find; conditional indexing Multi-way arrays File input and output Plotting Basic x-y plots Axes and titles Log plots Filled plots and bar plots Functions Polar plots Histogram plots 3d data Contour and image plots Perspective plots of surfaces over the x-y plane Scatter (cloud) plots Save plot to a graphics file Data analysis Set membership operators Statistics Interpolation and regression Non-linear methods Polynomials, root finding Differential equations Fourier analysis Symbolic algebra; calculus Programming Loops Conditionals Debugging Working directory and OS Credits
Description
R
MATLAB
IGOR
Indexing
1-based
1-based
0-based
Case sEnSiTiVe
Yes
Yes
No
Scalar
Variable
Scalar
Variable
List of numbers
Vector
Vector
1D Wave
Matrix of numbers
Matrix
Matrix
2D Wave or Matrix
Higher dimensions
Yes
Yes
Yes
Variables and
intnum = Doublelogilubridatecomplex4 integer types? datenum
Make/B a or Variable or NVARMake/D a or Variable or NVAR?
Text
chr? TextWave:Make/T a or String or SVAR
Mixed-type "matrix"
Yes
Yes
Generally no.id
Description
R
MATLAB
IGOR
Browse help interactively
help.start()docF1
Help on using help
help()help help or doc docDisplayHelpTopic "Help"
Help for a function
help(plot) or ?plothelp plotRight-click function name "Help for function" or ⎇+⌘+F1
Help for a toolbox/library package
helphelp splines or doc splines
Demonstration examples
demo()demoFile > Example Experiments
Example using a function
example(plot)Example using a function
Searching available documentation
Description
R
MATLAB
IGOR
Search help files
help.search('plot')lookfor plotF1
Find objects by partial name
apropos('plot')
List available packages
library()help
Locate functions
find(plot)which plotHelp > Command Help
List available methods for a function
methods(plot)
Description
R
MATLAB
IGOR
Start session
RguiFile > New Experiment or ⌘+N
Run code from file
source('foo.R')foo(.m)FunctionName()
Command history
history()See History Area
Save command history
savehistory(file=".Rhistory")diary on [..] diary offCreateHistoryCarbonCopy()
End session
q(save='no')exit or quitquit() or ⌘+Q
Description
R
MATLAB
IGOR
Help on operator syntax
help(Syntax)help -DisplayHelpTopic "Operators" or DisplayHelpTopic "MatrixOP"
Description
R
MATLAB
IGOR
Assignment; defining a number
a<-1; b<-2a=1; b=2;Variable a=1, b=2
Addition
a + ba + ba + b
Subtraction
a - ba - ba - b
Multiplication
a * ba * ba * b
Division
a / ba / ba / b
Power, a b
a ^ ba .^ ba ^ b
Remainder
a %% brem(a,b)mod(a,b)
Integer division
a %/% b
Factorial, n !
factorial(a)factorial(a)factorial(a)
Description
R
MATLAB
IGOR
Equal
a == ba == ba == b
Less than
a < ba < ba < b
Greater than
a > ba > ba > b
Less than or equal
a <= ba <= ba <= b
Greater than or equal
a >= ba >= ba >= b
Not Equal
a != ba ~= ba != b
Description
R
MATLAB
IGOR
Short-circuit logical AND
a && ba && ba && b
Short-circuit logical OR
`a
b`
Element-wise logical AND
a & ba & b or and(a,b)a & b
Element-wise logical OR
`a
b`
`a
Logical EXCLUSIVE OR
xor(a, b)xor(a, b)%^
Logical NOT
!a~a or not(a)!a
True if any element is nonzero
any(a)
True if all elements are nonzero
all(a)
Description
R
MATLAB
IGOR
Square root
sqrt(a)sqrt(a)sqrt(a)
Logarithm, base e (natural)
log(a)log(a)ln(a)
Logarithm, base 10
log10(a)log10(a)log(a)
Logarithm, base 2 (binary)
log2(a)log2(a)log(a) / log(2)
Exponential function
exp(a)exp(a)exp(a)
Description
R
MATLAB
IGOR
Round
round(a)round(a)round(a)
Round up
ceil(a)ceil(a)ceil(a)
Round down
floor(a)floor(a)floor(a)
Round towards zero
fix(a)trunc(a)
Description
R
MATLAB
IGOR
π = 3.141592pipipi
e = 2.718281exp(1)exp(1)e
Description
R
MATLAB
IGOR
Not a Number
NaNNaN
Infinity, ∞
Infinf
Description
R
MATLAB
IGOR
Imaginary unit
1iii
A complex number, 3 + 4i
z <- 3+4iz = 3+4ivariable/c z = cmplx(3,4)
Absolute value (modulus)
abs(3+4i) or Mod(3+4i)abs(z)sqrt(magSqr(z)
Real part
Re(3+4i)real(z)real(z)
Imaginary part
Im(3+4i)imag(z)imag(z)
Argument
Arg(3+4i)arg(z)
Complex conjugate
Conj(3+4i)conj(z)conj(z)
Description
R
MATLAB
IGOR
Arctangent, arctan(b /a )
atan2(b,a)atan(a,b)atan2(b,a)
Description
R
MATLAB
IGOR
Uniform distribution
runif(10)rand(1,10)Make/N=10 wave0 = 0.5 + enoise(0.5)
Uniform: Numbers between 2 and 7
runif(10, min=2, max=7)2+5*rand(1,10)Make/N=10 wave0 = 2+ + abs(enoise(5))
Uniform: 6,6 array
matrix(runif(36),6)rand(6)Make/N=(6,6) wave0 = enoise(1)
Normal distribution
rnorm(100,0,1)randn(100,1)Make/N=100 wave0 = gnoise(1)
Description
R
MATLAB
IGOR
Row vector, 1 × n -matrix
a <- c(2,3,4,5)a=[2 3 4 5];Make/N=4 a = {2, 3, 4, 5}
Column vector, m × 1-matrix
adash <- t(c(2,3,4,5))adash=[2 3 4 5]';Make/N=(1,4) adash = {2, 3, 4, 5}
Description
R
MATLAB
IGOR
1,2,3, … ,10
seq(10) or 1:101:10make/N=10 a = p+1
0.0,1.0,2.0, … ,9.0
seq(0,length=10)0:9Make/N=10 a = p
1,4,7,10
seq(1,10,by=3)1:3:10Make/N=4 a = p*3+1
10,9,8, … ,1
seq(10,1) or 10:110:-1:1make/N=10 a = 10-p
10,7,4,1
seq(from=10,to=1,by=-3)10:-3:1Make/N=4 a = 10-(p*3)
Linearly spaced vector of n=7 points
seq(1,10,length=7)linspace(1,10,7)Make/N=2 a = {1,10}Interpolate2/T=1/N=7/Y=a_L a
Reverse
rev(a)reverse(a)Reverse a
Set all values to same scalar value
a(:) = 3a = 3
Description
R
MATLAB
IGOR
Concatenate two vectors
c(a,a)[a a]Concatenate {a,a}, b
c(1:4,a)[1:4 a]Make/N=4 b = 1 + pConcatenate {b,a}, c
Description
R
MATLAB
IGOR
1 2 3, 1 2 3
rep(a,times=2)[a a]Concatenate/NP {a,a}, b
1 1 1, 2 2 2, 3 3 3
rep(a,each=3)Concatenate {a,a,a},bMatrixTranspose bRedimension/N=9 b
1, 2 2, 3 3 3
rep(a,a)
Description
R
MATLAB
IGOR
miss the first element
a[-1]a(2:end)a[1,*]
miss the tenth element
a[-10]a([1:9])a[0,numpnts(a)-2]
miss 1,4,7, …
a[-seq(1,50,3)]a[0,*;3]
last element
a(end)a[numpnts(a)-1]
last two elements
a(end-1:end)a[numpnts(a)-2,*]
Description
R
MATLAB
IGOR
pairwise max
pmax(a,b)max(a,b)max(a,b)
max of all values in two vectors
max(a,b)max([a b])max(wavemax(a),wavemax(b))
v <- max(a) ; i <- which.max(a)[v,i] = max(a)WaveStats a
Description
R
MATLAB
IGOR
Multiply two vectors
a*aa.*aMatrixOp b = a * a
Vector dot product, u ⋅ v
dot(u,v)MatrixOp b = u . v
Description
R
MATLAB
IGOR
Define a matrix
rbind(c(2,3),c(4,5))array(c(2,3,4,5), dim=c(2,2))a = [2 3;4 5]Make/N=(2,2) a = {{2,4},{3,5}}
Concatenation (matrices); rbind and cbind
Description
R
MATLAB
IGOR
Bind rows
rbind(a,b)[a ; b]Concatenate/NP=1 {a,b}, c
Bind columns
cbind(a,b)[a , b]Concatenate/NP=0 {a,b}, c
Concatenate matrices into one vector
[a(:), b(:)]?
Bind rows (from vectors)
rbind(1:4,1:4)[1:4 ; 1:4]Make/N=(2,4) a = 1 + q
Bind columns (from vectors)
cbind(1:4,1:4)[1:4 ; 1:4]'Make/N=(4,2) a = 1 + p
Description
R
MATLAB
IGOR
0 filled array
matrix(0,3,5) or array(0,c(3,5))zeros(3,5)Make/N=(3,5) a = 0
1 filled array
matrix(1,3,5) or array(1,c(3,5))ones(3,5)Make/N=(3,5) a = 1
Any number filled array
matrix(9,3,5) or array(9,c(3,5))ones(3,5)*9Make/N=(3,5) a = 9
Identity matrix
diag(1,3)eye(3)Identity matrix
Diagonal
diag(c(4,5,6))diag([4 5 6])Make/N=(3,3) a = 4+pMatrixOp b = diagonal(a)
Magic squares; Lo Shu
magic(3)?
Reshape and flatten matrices
Description
R
MATLAB
IGOR
Reshaping (rows first)
matrix(1:6,nrow=3,byrow=T)reshape(1:6,3,2)';Make/N=6 a = 1 + pRedimension/N=(2,3) a
Reshaping (columns first)
matrix(1:6,nrow=2)array(1:6,c(2,3))reshape(1:6,2,3);As above, then MatrixTranspose a
Flatten to vector (by rows, like comics)
as.vector(t(a))a'(:)WaveTranspose aRedimension/N=(numpnts(a)) a
Flatten to vector (by columns)
as.vector(a)a(:)Redimension/N=(numpnts(a)) a
Flatten upper triangle (by columns)
a[row(a) <= col(a)]vech(a)?
Description
R
MATLAB
IGOR
Copy of a
b = ab = aDuplicate a, b
Indexing and accessing elements (Python: slicing)
Description
R
MATLAB
IGOR
Input is a 3,4 array
a <- rbind(c(11, 12, 13, 14),c(21, 22, 23, 24),c(31, 32, 33, 34))a = [ 11 12 13 14 ...21 22 23 24 ...31 32 33 34 ]Make/N=(4,3) a = {{11,12,13,14},{21,22,23,24},{31,32,33,34}}MatrixTranspose a
Element 2,3 (row,col)
a[2,3]a(2,3)a[1][2]
First row
a[1,]a(1,:)a[0][]
First column
a[,1]a(:,1)a[][0]
Array as indices
a([1 3],[1 4]);?
All, except first row
a[-1,]a(2:end,:)a[1,*][]
Last two rows
a(end-1:end,:)a[dimsize(a,0)-2,][]
Strides: Every other row
a(1:2:end,:)a[0,*;2][]
All, except row,column (2,3)
a[-2,-3]?
Remove one column
a[,-2]a(:,[1 3 4])DeletePoints/M=1 0,1,a
Description
R
MATLAB
IGOR
a[,1] <- 99a(:,1) = 99a[][1] = 99
a[,1] <- c(99,98,97)a(:,1) = [99 98 97]'a[][1] = {99,98,97} or a[][1] = 99 - p
Clipping: Replace all elements over 90
a[a>90] <- 90a(a>90) = 90;a = (a[p][q] > 90) ? 90 : a[p][q]
Description
R
MATLAB
IGOR
Transpose
t(a)a'MatrixTranspose a
Non-conjugate transpose
a.' or transpose(a)MatrixTranspose/H a
Determinant
det(a)det(a)MatrixDet a or MatrixOp b = det(a)
Inverse
solve(a)inv(a)MatrixInverse a
Pseudo-inverse
ginv(a)pinv(a)MatrixInverse/P a
Norms
norm(a)norm(a)
Eigenvalues
eigen(a)$valueseig(a)MatrixEigenV a
Singular values
svd(a)$dsvd(a)MatrixSVD a
Cholesky factorization
chol(a)MatrixOp chol(a)
Eigenvectors
eigen(a)$vectors[v,l] = eig(a)MatrixEigenV a
Rank
rank(a)rank(a)MatrixRank(a)
Description
R
MATLAB
IGOR
Sum of each column
apply(a,2,sum)sum(a)MatrixOp b = sumCols(a)
Sum of each row
apply(a,1,sum)sum(a')MatrixOp b = sumRows(a)
Sum of all elements
sum(a)sum(sum(a))Sum(a)
Cumulative sum (columns)
apply(a,2,cumsum)cumsum(a)MatrixOp b = sumCols(a)Integrate/DIM=1 b
Description
R
MATLAB
IGOR
a <- rbind(c(4,3,2),c(2,8,6),c(1,4,7))a = [ 4 3 2 ; 2 8 6 ; 1 4 7 ]Make/N=(3,3) a = {{4,2,1},{3,8,4},{2,6,7}}
Flat and sorted
t(sort(a))sort(a(:))Redimension/N=9 aSort a,a
Sort each column
apply(a,2,sort)sort(a)SortColumns keywaves={a},sortwaves={a}
Sort each row
t(apply(a,1,sort))sort(a')'SortColumns following MatrixTranspose
Sort rows (by first row)
sortrows(a,1)?
Sort, return indices
order(a)MakeIndex a,b ?
Description
R
MATLAB
IGOR
max in each column
apply(a,2,max)max(a)MatrixOp b=maxCols(a)
max in each row
apply(a,1,max)max(a')MatrixOp b=a^tMatrixOp c=maxCols(b)
max in array
max(a)max(max(a))MatrixOp b=maxVal(a)or WaveStats a
return indices, i
i <- apply(a,1,which.max)[v i] = max(a)WaveStats a
pairwise max
pmax(b,c)max(b,c)max(b,c)
apply(a,2,cummax)cummax(a)max(sum(b),sum(c))
Description
R
MATLAB
IGOR
Flip left-right
a[,4:1]fliplr(a)MatrixOp b=reverseRows(a)
Flip up-down
a[3:1,]flipud(a)MatrixOp b=reverseCols(a)
Rotate 90 degrees
rot90(a)MatrixOp b=a^t
Repeat matrix: [ a a a ; a a a ]
kronecker(matrix(1,2,3),a)repmat(a,2,3)Concatenate/NP=1 {a,a,a},bConcatenate/NP=0 {b,b},c
Triangular, upper
a[lower.tri(a)] <- 0triu(a)?
Triangular, lower
a[upper.tri(a)] <- 0tril(a)?
Description
R
MATLAB
IGOR
Matrix dimensions
dim(a)size(a)WaveInfo(a) or see Data Browser
Number of columns
ncol(a)size(a,2) or length(a)dimsize(a,1)
Number of elements
prod(dim(a))length(a(:))numpnts(a)
Number of dimensions
ndims(a)WaveDims(a)
Number of bytes used in memory
object.size(a)WaveInfo(a) or see Data Browser
Matrix- and elementwise- multiplication
Description
R
MATLAB
IGOR
Elementwise operations
a * ba .* bMatrixOp c = a * b
Matrix product (dot product)
a %*% ba * bMatrixOp c = a . b
Outer product
outer(a,b) or a %o% bb * aMatrixMultiply a,b
Cross product
crossprod(a,b) or t(a) %*% bCross a,b
Kronecker product
kronecker(a,b)kron(a,b)MatrixOp c = tensorProduct(a,b)
Matrix division, b ⋅ a −1
a / bMatrixOp c = a / b
Left matrix division, b −1 ⋅ a
solve(a,b)a \ b?
Find; conditional indexing
Description
R
MATLAB
IGOR
Non-zero elements, indices
which(a != 0)find(a)Duplicate a,b b = (a != 0) ? p : NaNWaveTransform zapnans b
Non-zero elements, array indices
which(a != 0, arr.ind=T)[i j] = find(a)Write a loop
Vector of non-zero values
ij <- which(a != 0, arr.ind=T); v <- a[ij][i j v] = find(a)a = (a[p][q] != 0) ? a[p][q] : NaNRedimension/N=(numpnts(a)) aWaveTransform a
Condition, indices
which(a>5.5)find(a>5.5)Duplicate a,b b = a[p][q] > 5.5 ? p : NaNWaveTransform zapnans b
Return values
ij <- which(a>5.5, arr.ind=T); v <- a[ij]Duplicate a,b b = a[p][q] > 5.5 ? a[p][q] : NaNWaveTransform zapnans b
Zero out elements above 5.5
a .* (a>5.5)a = (a[p][q] > 5.5) ? 0 : a[p][q]
Description
R
MATLAB
IGOR
Define a 3-way array
a = cat(3, [1 2; 1 2],[3 4; 3 4]);Make/N=(2,2,2) a={{{1,1},{2,2}},{{3,3},{4,4}}}
a(1,:,:)Make/N=(1,2,2) bb[0][][]=a[p][q][r]
Description
R
MATLAB
IGOR
Reading from a file (2d)
f <- read.table("data.txt")f = load('data.txt')Data > Load Waves...
Reading fram a CSV file (2d)
f <- read.table(file="data.csv", sep=";")x = dlmread('data.csv', ';')LoadWave/J/M/D/N=wave/O/K=0 "data.csv"
Writing to a file (2d)
write(f,file="data.txt")save -ascii data.txt fSave/J/M="\n"/W f as "data.txt"
###Plotting
Description
R
MATLAB
IGOR
1d line plot
plot(a, type="l")plot(a)display a
2d scatter plot
plot(x[,1],x[,2])plot(x(:,1),x(:,2),'o')display a vs b
Two graphs in one plot
plot(x1,y1, x2,y2)display a, b or display a1 vs b1, a2 vs b2
Overplotting: Add new plots to current
plot(x1,y1)matplot(x2,y2,add=T)plot(x1,y1)hold onplot(x2,y2)display a; AppendToGraph b
subplots
subplot(211)Add to procedure window#include <InsertSubwindowInGraph>
Plotting symbols and color
plot(x,y,type="b",col="red")plot(x,y,'ro-')Double-click trace on graph
Description
R
MATLAB
IGOR
Turn on grid lines
grid()grid onModifyGraph grid=1
1:1 aspect ratio
plot(c(1:10,10:1), asp=1)axis equalModifyGraph width={Plan,1,bottom,left}
Set axes manually
plot(x,y, xlim=c(0,10), ylim=c(0,5))axis([ 0 10 0 5 ])SetAxis left 0,5SetAxis bottom 0,10
Axis labels and titles
plot(1:10, main="title",xlab="x-axis", ylab="y-axis")title('title')xlabel('x-axis')ylabel('y-axis')Label left "y-axis"Label bottom "x-axis"
Description
R
MATLAB
IGOR
logarithmic y-axis
plot(x,y, log="y")semilogy(a)ModifyGraph log(left)=1
logarithmic x-axis
plot(x,y, log="x")semilogx(a)ModifyGraph log(bottom)=1
logarithmic x and y axes
plot(x,y, log="xy")loglog(a)ModifyGraph log=1
Filled plots and bar plots
Description
R
MATLAB
IGOR
Filled plot
plot(t,s, type="n", xlab="", ylab="")polygon(t,s, col="lightblue")polygon(t,c, col="lightgreen")fill(t,s,'b', t,c,'g')Display aModifyGraph mode=7
Stem-and-Leaf plot
stem(x[,3])?
Description
R
MATLAB
IGOR
Defining functions
f <- function(x) sin(x/3) - cos(x/5)f = inline('sin(x/3) - cos(x/5)')Make a = sin(x/3) - cos(x/5
Plot a function for given range
plot(f, xlim=c(0,40), type='p')ezplot(f,[0,40])fplot('sin(x/3) - cos(x/5)',[0,40])Display a[0,40]
Description
R
MATLAB
IGOR
theta = 0:.001:2*pi;r = sin(2*theta);
Polar plot
See polar.plot
polar(theta, rho)#include <New Polar Graphs>
Description
R
MATLAB
IGOR
hist(rnorm(1000))hist(randn(1000,1))Make/O/N=1000 a=gnoise(1)Make/N=0/O a_HistHistogram/B=3 a,a_HistDisplay a_Hist
hist(rnorm(1000), breaks= -4:4)hist(randn(1000,1), -4:4)As above exceptMake/N=8/O a_HistHistogram/B={-4,1,8} a,a_Hist
hist(rnorm(1000),breaks=c(seq(-5,0,0.25),seq(0.5,5,0.5)), freq=F)Concatenate two sub-histograms
plot(apply(a,1,sort),type="l")plot(sort(a))?
Description
R
MATLAB
IGOR
Contour plot
contour(z)contour(z)Display; AppendMatrixContour z
Filled contour plot
filled.contour(x,y,z,nlevels=7, color=gray.colors)contourf(z); colormap(gray)Display; AppendMatrixContour zModifyContour z fill=1
Plot image data
image(z, col=gray.colors(256))image(z)colormap(gray)newimage z or display;appendimage z
Direction field vectors
quiver()DisplayHelpTopic "ModifyGraph for Traces"
Perspective plots of surfaces over the x-y plane
Description
R
MATLAB
IGOR
f <- function(x,y) x*exp(-x^2-y^2)n <- seq(-2,2, length=40)z <- outer(n,n,f)n=-2:.1:2;[x,y] = meshgrid(n,n);z=x.*exp(-x.^2-y.^2);
Mesh plot
persp(x,y,z, theta=30, phi=30, expand=0.6, ticktype='detailed')mesh(z)ImageInterpolate/CMSH voronoi aAppendToGizmo surface=root:a,name=surface0ModifyGizmo ModifyObject=surface0,objectType=surface,property={ fillMode,3}
Surface plot
persp(x,y,z, theta=30, phi=30, expand=0.6, col='lightblue', shade=0.75, ltheta=120, ticktype='detailed')surf(x,y,z) or surfl(x,y,z)Concatenate {x,y,z},wave3DNewGizmoAppendToGizmo Scatter=root:wave3d,name=surface0
Description
R
MATLAB
IGOR
3d scatter plot
cloud(z~x*y)plot3(x,y,z,'k+')Concatenate {x,y,z},wave3DNewGizmoAppendToGizmo Scatter=root:wave3d,name=scatter0
Save plot to a graphics file
Description
R
MATLAB
IGOR
PostScript
postscript(file="foo.eps")plot(1:10)dev.off()plot(1:10)print -depsc2 foo.epsSavePict/E=-3 as "foo.eps"
PDF
pdf(file='foo.pdf')SavePict/E=-2 as "foo.pdf"
SVG (vector graphics for www)
devSVG(file='foo.svg')SavePict/E=-9 as "foo.svg"
PNG (raster graphics)
png(filename = "Rplot%03d.png"print -dpng foo.pngSavePict/E=-5 as "foo.png"
Description
R
MATLAB
IGOR
Create sets
a <- c(1,2,2,5,2)b <- c(2,3,4)a = [ 1 2 2 5 2 ];b = [ 2 3 4 ];Create sets
Set unique
unique(a)unique(a)FindDuplicates/RN=c a
Set union
union(a,b)union(a,b)? via loop
Set intersection
intersect(a,b)intersect(a,b)? via loop
Set difference
setdiff(a,b)setdiff(a,b)? via loop
Set exclusion
setdiff(union(a,b),intersect(a,b))setxor(a,b)? via loop
True for set member
is.element(2,a) or 2 %in% aismember(2,a)FindValue/I=2 a
Description
R
MATLAB
IGOR
Average
apply(a,2,mean)mean(a)mean(a)WaveStats a or ImageStats a gives many statistics
Median
apply(a,2,median)median(a)median(a) or statsmedian(a)
Standard deviation
apply(a,2,sd)std(a)WaveStats a
Variance
apply(a,2,var)var(a)Variance(a)
Correlation coefficient
cor(x,y)corr(x,y)StatsCorrelation x,y or Correlate x,y
Covariance
cov(x,y)cov(x,y)MatrixCorr/COV x,y
Interpolation and regression
Description
R
MATLAB
IGOR
Straight line fit
z <- lm(y~x)plot(x,y)abline(z)z = polyval(polyfit(x,y,1),x)plot(x,y,'o', x,z ,'-')CurveFit line b /X=a /D
Linear least squares y = a__x + b
solve(a,b)a = x\yMatrixLLS a,b
Polynomial fit
polyfit(x,y,3)`CurveFit Poly2D 3 a /Ywave=b
Polynomials, root finding
Description
R
MATLAB
IGOR
Find zeros of polynomial
polyroot(c(1,-1,-1))roots([1 -1 -1])Make a={1,-1,-1}FindRoots/P=a
Find a zero near x = 1
f = inline('1/x - (x-1)')fzero(f,1)?
Solve symbolic equations
solve('1/x = x-1')?
Evaluate polynomial
polyval([1 2 1 2],1:10)?
Description
R
MATLAB
IGOR
Discrete difference function and approximate derivative
diff(a)?
Solve differential equations
Differentiate a ?
Description
R
MATLAB
IGOR
Fast fourier transform
fft(a)fft(a)FFT a
Inverse fourier transform
fft(a, inverse=TRUE)ifft(a)IFFT a
Symbolic algebra; calculus
Description
R
MATLAB
IGOR
Factorization
FUN <- function(x) {x <- as.integer(x)div <- seq_len(abs(x))factors <- div[x %% div == 0L]factors <- list(neg = -factors, pos = factors)return(factors)}factor()Only PrimeFactors a
Description
R
MATLAB
IGOR
Script file extension
.R.m.ipf
Comment symbol (rest of line)
#%//
Import library functions
library(RSvgDevice)% must be in MATLABPATH#include "Name"
Eval
string <- "a <- 234"eval(parse(text=string))string='a=234';eval(string)String a = "234"str2num(a)
Description
R
MATLAB
IGOR
for-statement
for(i in 1:5) print(i)for i=1:5; disp(i); end
Multiline for statements
for(i in 1:5) {print(i)print(i*2)}for i=1:5disp(i)disp(i*2)endfor(i=0;i<10;i+=1)print iendfor
Description
R
MATLAB
IGOR
if-statement
if (1>0) a <- 100if 1>0 a=100; endif (1 > 0)a = 100endif
if-else-statement
if 1>0 a=100; else a=0; endif (1 < 0)a = 100elsea=0 endif
Ternary operator (if?true:false)
ifelse(a>0,a,0)a = a[] > 0 ? a[p] : 0
Description
R
MATLAB
IGOR
Most recent evaluated expression
.Last.valueansArrow up
List variables loaded into memory
objects()whos or whoData > Data Browser
Clear variable x from memory
rm(x)clear x or clear [all]KillVariables or KillStringsor KillWaves
Print
print(a)disp(a)Print a
Description
R
MATLAB
IGOR
List files in directory
list.files() or dir()dir or lsData > Data Browser
List script files in directory
list.files(pattern="\.r$")whatWindow > Procedure Window
Displays the current working directory
getwd()pwdGetDataFolder(0)
Change working directory
setwd('foo')cd fooSetDataFolder $expDataFolderName
Invoke a System Command
system("notepad")!notepadExecute "command"
##Credits
The original R-MATLAB cheat sheet was taken from ©2006 Vidar Bronken Gundersen, /mathesaurus.sf.net
An edited version with added IgorPro commands was made by Ben Gallarda