sdfa
ls()
demo
ls()
q()
setwd("L:/Data/Teaching/MyCourse/105-1_Programming/Code")
c( 1.2, -6.5, -3.4, 4.3, 5.6, -2.1)
maxtix( c( 1.2, -6.5, -3.4, 4.3, 5.6, -2.1) )
matrix( c( 1.2, -6.5, -3.4, 4.3, 5.6, -2.1) )
matrix( c( 1.2, -6.5, -3.4, 4.3, 5.6, -2.1), nrow = 2 )
matrix( c( 1.2, -6.5, -3.4, 4.3, 5.6, -2.1), nrow = 2, ncol = 3 )
matrix( c( 1.2, -6.5, -3.4, 4.3, 5.6, -2.1), nrow = 2, ncol = 2 )
matrix( c( 1.2, -6.5, -3.4, 4.3, 5.6, -2.1), nrow = 2, ncol = 1 )
matrix( c( 1.2, -6.5, -3.4, 4.3, 5.6, -2.1), nrow = , ncol = 1 )
matrix( c( 1.2, -6.5, -3.4, 4.3, 5.6, -2.1), nrow = 3, ncol = 1 )
matrix( c( 1.2, -6.5, -3.4, 4.3, 5.6, -2.1), nrow = 3, ncol = 2 )
matrix( c( 1.2, -6.5, -3.4, 4.3, 5.6, -2.1), nrow = 2, ncol = 3 )
matrix( c( 1.2, -6.5, -3.4, 4.3, 5.6, -2.1), nrow = 2, ncol = 3, byrow = TRUE )
matrix( c( 1.2, -6.5, -3.4, 4.3, 5.6, -2.1), nrow = 3, ncol = 2, byrow = TRUE )
matrix( c( 1.2, -6.5, -3.4, 4.3, 5.6, -2.1), nrow = 3, ncol = 2, byrow = FALSE)
matrix( c( 1.2, -6.5, -3.4, 4.3, 5.6, -2.1), nrow = 2, ncol = 3 )
A <- matrix( c( 1.2, -6.5, -3.4, 4.3, 5.6, -2.1), nrow = 2, ncol = 3 )
A
B <- matrix( c( 1.2, -3.4, 5.6, -6.5, 4.3, -2.1), nrow = 2, ncol = 3 )
B <- matrix( c( 1.2, -3.4, 5.6, -6.5, 4.3, -2.1), nrow = 2, ncol = 3 )
B
B <- matrix( c( 1.2, -3.4, 5.6, -6.5, 4.3, -2.1), nrow = 2, ncol = 3, byrow = TRUE )
B
A
B
class( A )
dim( A )
attribute( A )
attributes( A )
nrow( A )
ncol( A )
dim( A )
dim( A )[1]
dim( A )[2]
A <- matrix( c( 1.2, -6.5, -3.4, 4.3, 5.6, -2.1 ), nrow = 2, ncol = 3 )
A
as.numeric( A )
u <- as.numeric( A )
u
B
C <- matrix( c( 1.2, -6.5, -3.4, 4.3, 5.6, -2.1 ), nrow = 2, ncol = 3, byrow = TRUE )
A
C
uc <- as.numeric( C )
uc
ua <- as.numeric( A )
ua
c(A)
v <- c(A)
v
dim(v)
length( v )
nrow(A)
ncol(A)
nrow( A ) * ncol( A )
length( A )
matrix( 0, nrow = 2, ncol = 3 )
matrix( 0, nrow = 2, ncol = 3 )
matrix( 0, nrow = 3, ncol = 3 )
diag(  0, nrow = 3 )
diag( 0, nrow = 3 )
diag( 0 )
diag( 3 )
diag( 1 )
diag( 2 )
diag( 3 )
diag( 0, nrow = 4 )
diag( 2.5 )
diag( 2.5, nrow = 3 )
?diag
diag( c(1,2,3) )
diag( c(1,2,3), nrow =3 )
A <- matrix( 1:9, nrow = 3, ncol = 3 )
A <- matrix( 1:9, nrow = 3, ncol = 3 )
A
B <- matrix( 1:9, nrow = 3, ncol = 3, byrow = TRUE )
B
A + B
A - B
A %*% B
A * B
A
B
A*B
A %*% B
A <- matrix( 1:9, nrow = 3, ncol = 3 )
B <- matrix( 1:9, nrow = 3, ncol = 3, byrow = TRUE )
A
B
A[2,3]
A[1,1]
A[1,2]
A[1,3]
A[2,1]
A[2,2]
A[3,1]
A[4]
A[1]
A[2]
A[3]
A[4]
A[5]
c(A)
c(A)[4]
A[4]
A[1,]
A
A[1,]
A[2,]
A[3,]
R1 <- A[ 1, ]
R1
class( R1 )
R1[ 1, 2 ]
R1
R1[1]
R1[2]
R1[3]
R1 * B
B
R1 * B
R1 %*% B
A <- matrix( 1:9, nrow = 3, ncol = 3 )
B <- matrix( 1:9, nrow = 3, ncol = 3, byrow = TRUE )
A[1, drop = FALSE]
A[1, , drop = FALSE]
RR1 <- A[1, , drop = FALSE]
RR1
RR1[1,2]
RR1
A
A[1, ]
RR2 <- A[1, ]
RR2
RR1
RR1 %*% B
R1 %*% B
R1
as.matrix( R1 )
A <- matrix( 1:9, nrow = 3, ncol = 3 )
A[ c(1,3),]
E <- A[ c(1,3),]
E
class( E )
A[ c(1,3), 2]
A
F <- A[ c(1,3), 2]
F
class( F )
C <- matrix( 1:4, nrow = 2, ncol = 2 )
D <- matrix( 1:6, nrow = 2, ncol = 3 )
C
D
cbind( C, D )
E <- matrix( 1:4, nrow = 2, ncol = 2 )
F <- matrix( 1:6, nrow = 3, ncol = 2 )
E
F
rbind( E, F )
cbind( E, F )
A <- matrix( 1:9, nrow = 3, ncol = 3 )
t( A )
A
t( A )
t( A ) %*% A
A %*% t( A )
diag( A )
A
sum( diag( A ) )
A <- matrix( c(1, 0, 0, 3, 0.5, 0, 2, 1, 0.25), nrow = 3, ncol = 3 )
A
det( A )
?det
solve( A )
Ainv <- solve( A )
A
Ainv
A %*% Ainv
Ainv %*% A
A <- matrix( c(1, 0, 0, 3, 0.5, 0, 2, 1, 0.25), nrow = 3, ncol = 3 )
b <- c(2, 1, 3)
solve( A, b )
A
b
Ainv <- solve( A )
Ainv
Ainv %*% b
?solve
list(c("Leica", "Pentax", "Olympus", "Nikon"), c(1.2, 3.4), c("red", "green", "blue"))
c("Leica", "Pentax", "Olympus", "Nikon")
c(1.2, 3.4)
c("red", "green", "blue")
list( c("Leica", "Pentax", "Olympus", "Nikon"), c(1.2, 3.4), c("red", "green", "blue") )
list( brand = c("Leica", "Pentax", "Olympus", "Nikon"), number = c(1.2, 3.4), color = c("red", "green", "blue") )
camera <- list( brand = c("Leica", "Pentax", "Olympus", "Nikon"), number = c(1.2, 3.4), color = c("red", "green", "blue") )
camera
camera
camera[1]
camera[2]
camera[3]
camera[ "brand"]
camera[ "number"]
a1 <- camera[ "brand"]
class( a1 )
camera[[1]]
a2 <- camera[[1]]
a2
a1
a2
class( a2 )
camera[[ "brand" ]]
camera$brand
a3 <- camera$brand
class(a3)
a1
a1[1]
camera[1][1]
a2
a2[ c(1,2) ]
a2[ c(1,2,3) ]
a2[ c(2,3) ]
class(a2)
class(a3)
a3
a3[2]
savehistory("L:/Data/Teaching/MyCourse/105-1_Programming/Code/data_161015_HW04_Matrix-DataFrame-1.Rhistory")
x1 <- c("father", "mother", "brother", "sister")
x2 <- c("Leica", "Pentax", "Olympus", "Nikon")
x3 <- c("gold", "red", "green", "blue")
x4 <- c(2, 1, 1, 2)
x1
x2
x3
x4
class(c4)
class(x4)
camera <- data.frame(member = x1, brand = x2, color = x3, amount = x4)
camera
class( camera )
names( camera )
colnames( camera )
rownames( camera )
camera$brand
camera[1,1]
camera[,2]
camera[,1]
camera[,2]
camera[,3]
camera[,4]
camera[1,]
camera[2,]
camera[,"brand"]
camera[,"color"]
camera["color",]
camera["1",]
camera["2",]
x5 <- c(8,3,2,2)
x5
camera$cost <- x5
camera
test <- camera
test
class(test)
colnames(test)
colnames(test)[ c(4,5) ]
colnames(test)[ c(4, 5) ]
colnames(test)[ c(4, 5) ] <- c( "number", "money")
test
camera
camera[ camera$brand == "Leica" ]
camera
camera[ camera$brand == "Leica" ]
camera[ camera$brand == "Leica", ]
subset( camera, brand = "Leica" )
subset( camera, brand == "Leica" )
camera
camera[ camera$brand %in% c("Leica", "Nikon" ) ]
camera[ camera$brand %in% c("Leica", "Nikon" ), ]
camera[ camera$brand %in% c("Leica" ), ]
camera[ camera$brand %in% c("Leica", "Nikon" ), ]
subset( camera, brand %in% c("Leica"))
subset( camera, brand %in% c("Leica", "Nikon"))
camera
camera[] camera$cost > 2, ]
camera[ camera$cost > 2, ]
camera[ camera$cost >= 2, ]
camera[ camera$cost >= 5, ]
camera[ camera$cost >= 3, ]
subset( camera, cost > 2 )
subset( camera, cost > 3 )
subset( camera, cost >= 3 )
A <- matrix( c(1.2, -6.5, -3.4, 4.3, 5.6, -2.1), nrow = 2, ncol = 3 )
A
rownames( A )
colnames( A )
as.data.frame( A )
D <- as.data.frame( A )
D
class( A )
class( D )
names( D )
colnames( D )
rownames( D )
D$V1
D$V2
D$V3
camera
camera[ , c(3,4)]
camera[ , c(4,5)]
KK <- camera[ , c(4,5)]
KK
class(KK)
as.matrix(KK)
as.matrix(KK[,1])
as.matrix(KK[,2])
MM <- as.matrix(KK[,1])
MM
MM[,2] <- as.matrix(KK[,2])
MM
MM2
MM2 <- as.matrix(KK[,2])
MM1 <- as.matrix(KK[,1])
MM1
MM2
MM <- cbind( MM1, MM2 )
MM
t(MM)
x <- c("R", "G", "B", "R", "R", "B", "R", "G", "G")
class( X )
class( x )
y <- factor( x )
class( y )
y
as.integer( y )
levels( y )
levels( y )[2]
nlevels( y )
nlevels( y )[ as.integer( y ) ]
levels( y )[ as.integer( y ) ]
gl( 5, 3)
gl( 5, 3 )
?gl
gl( n = 5, k = 3)
fa <- gl( n = 5, k = 3)
class( fa )
gl( 5, 2, 13 )
gl( n=5, k = 2, length = 13 )
is.factor( gl( 5, 2, 13 ))
savehistory("L:/Data/Teaching/MyCourse/105-1_Programming/Code/data_161015_HW04_Matrix-DataFrame-2.Rhistory")