help()
assign("x", c(1,2,3))
x
y<-(1,2,3,4,5,6)
y<-c(1,2,3,4,5,6)
t(x)
x + y
y + x
z<-c(2,4,5,6)
x + z
w<-c(x,0,3,x)
w
x[2]
ls()
"last.warning"
last.warning
rm last.warning
rm(last.warning)
ls()
x<-c(1:10)
x
x<-c(2*1:15)
x
1:15
2*1:15-1
seq(from=1, to=10, by=1, length=10)
seq(from=1, to=10, by=1)
seq(from=1, by=1, length = 10)
seq(from=1, by=1, length = 20)
seq(along=x)
x
seq(along=y)
help("seq")
seq(3, 14, 2)
seq(3,2,length=10)
seq(3,2,length=6)
seq(3,2,by=2)
seq(3,2,2)
seq(from=3,to=2,by=2)
seq(from=3,to=14,by=2)
x5<-rep(x, times=5)
x5
range(x5)
min(x5)
max(x5)
range(x5)[1]
sort(x5)
sort(y,z)
sort(z,y)
help("sort")
sqrt(pi)
sqrt(w)
sqrt(-14)
sqrt(-17 + 0i)
5 <= 3
5 == 5
5 = 5
a = 3
a
a = "3
a = "3"
a
3 == "3"
"3monkey" + 1
"3" + 1
inf
"aaaa" <= "aaa"
"aaaa" <= "aab"
"a" < "b"
c("ls", "seq")
b<-c(1,3,5,7,9)
b>5
d<-b>5
d
!d
0/0
0/5
5/0
c(2:5, NA, 0,1, NA, Inf)
u=c(2:5, NA, 0, 1, NA, Inf)
u
p = u[!is.na(u)]
p
p = u[!is.na(u) & u>2]
p
m = array(1:20, dim=c(4,5))
m
array(0, c(4,5)
)
help(array)
m1=array(0:5, dim=c(4,5))
m1
help(matrix)
matrix(1:20, 5, 4)
matrix(1:20, 5, 4, true)
matrix(1:20, 5, 4, TRUE)
matrix(1:20, 5, 4, c=TRUE)
2*m1*m+m+1
m %*% m
m %*% m1
m1 %*% m
mm = m %*% t(m)
mm
x %*% t(x)
t(x) %*% x
x x x
crossprod(x)
nrow(m)
ncol(n)
ncol(m)
v
v<-c(1,2,3,4)
diag(v)
help(diag)
diag(diag(v))
diag(m)
# rem
# Ax = B, x = B * A^-1
A = matrix(c(1,2,0,3,-4,3,5,1,-2), 3, 3)
a
A
b = c(-7, 27, -17)
b
B = b
solve(A, B)
A
solve(A)
solve(A) %*% b
library.MASS
library.MASS
library.mass
# ginv(...) - pseudoinv. matica
library(MASS)
ginv(A)
# vlasne cislo matice
eigen(A)
# musi byt stvorc. matica
eigen(A)$values
eigen(A)$va
eigen(A)$vec
eigen(A)$vec[2,3]
eigen(A)$vec[,3]
# log = ln
log(3)
log10(3)
help(logb)
logb(27,3)