R version 4.2.3 (2023-03-15 ucrt) -- "Shortstop Beagle"
Copyright (C) 2023 The R Foundation for Statistical Computing
Platform: x86_64-w64-mingw32/x64 (64-bit)

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Type 'demo()' for some demos, 'help()' for on-line help, or
'help.start()' for an HTML browser interface to help.
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> help.start()
starting httpd help server ... done
If nothing happens, you should open
‘http://127.0.0.1:21147/doc/html/index.html’ yourself
> ?plot
> help.search("plot")
> a <- 0
> (1 + 2)^4 -> b
> a
[1] 0
> b
[1] 81
> 3+4
[1] 7
> A
Error: object 'A' not found
> .Last.value
[1] 7
> 3^2 + 4
[1] 13
> .Last.value
[1] 13
> (1 + 2)^2 -> c
> 3/4
[1] 0.75
> Inf
[1] Inf
> NaN
[1] NaN
> 4/0
[1] Inf
> Inf-Inf
[1] NaN
> NA
[1] NA
> mode(NA)
[1] "logical"
> mode(a)
[1] "numeric"
> mode(NaN)
[1] "numeric"
> mode("abc")
[1] "character"
> class(a)
[1] "numeric"
> TRUE
[1] TRUE
> FALSE
[1] FALSE
> T
[1] TRUE
> F
[1] FALSE
> a <- "abc"
> a
[1] "abc"
> as.character(b)
[1] "81"
> b
[1] 81
> s <- "3.14"
> s
[1] "3.14"
> as.numeric(s)
[1] 3.14
> mode(a)
[1] "character"
> is.character(a)
[1] TRUE
> b
[1] 81
> c
[1] 9
> b+c
[1] 90
> b-c
[1] 72
> b*c
[1] 729
> b/c
[1] 9
> b^c
[1] 1.500946e+17
> b %% c
[1] 0
> b %/% c
[1] 9
>  2 == 3
[1] FALSE
> b > 2
[1] TRUE
> b >= 3
[1] TRUE
> b %% 2 == 0
[1] FALSE
> b
[1] 81
> (b > 2) | (b < -2)
[1] TRUE
> (b > 2) & (b < -2)
[1] FALSE
> v <- c(1,4,-2.5,"abc")
> v
[1] "1"    "4"    "-2.5" "abc" 
> w <- c(3,-2,4.23)
> d <- 3+i
Error: object 'i' not found
> d <- 3+1i
> d
[1] 3+1i
> mode(d)
[1] "complex"
> w
[1]  3.00 -2.00  4.23
> x <- c(2,0)
> c(w,x)
[1]  3.00 -2.00  4.23  2.00  0.00
> 2:4
[1] 2 3 4
> 2:6
[1] 2 3 4 5 6
> 2:5.5
[1] 2 3 4 5
> 6:2
[1] 6 5 4 3 2
> y <- 2:7
> y
[1] 2 3 4 5 6 7
> ?seq
> seq()
[1] 1
> seq(2.7)
[1] 1 2
> seq(2,7)
[1] 2 3 4 5 6 7
> seq(2,7,2)
[1] 2 4 6
> seq(from=2,to=7,by=2)
[1] 2 4 6
> seq(from=2,to=7,length=3)
[1] 2.0 4.5 7.0
> seq(7,2,length=3)
[1] 7.0 4.5 2.0
> seq(2,by=5,length=10)
 [1]  2  7 12 17 22 27 32 37 42 47
> rnorm(10)
 [1] -1.5346491  0.6205262 -1.6287462 -0.4085084 -0.1473771  1.1239941
 [7]  1.4686672  0.7133718  3.2031953 -0.2889531
> v
[1] "1"    "4"    "-2.5" "abc" 
> w
[1]  3.00 -2.00  4.23
> x
[1] 2 0
> y
[1] 2 3 4 5 6 7
> z <- y/2
> z
[1] 1.0 1.5 2.0 2.5 3.0 3.5
> y
[1] 2 3 4 5 6 7
> 2+y
[1] 4 5 6 7 8 9
> 2^y
[1]   4   8  16  32  64 128
> y^2
[1]  4  9 16 25 36 49
> sin(y)
[1]  0.9092974  0.1411200 -0.7568025 -0.9589243 -0.2794155  0.6569866
> abs(w)
[1] 3.00 2.00 4.23
> w
[1]  3.00 -2.00  4.23
> z 
[1] 1.0 1.5 2.0 2.5 3.0 3.5
> w
[1]  3.00 -2.00  4.23
> y
[1] 2 3 4 5 6 7
> y + z
[1]  3.0  4.5  6.0  7.5  9.0 10.5
> z / y
[1] 0.5 0.5 0.5 0.5 0.5 0.5
> length(y)
[1] 6
> length(x)
[1] 2
> x
[1] 2 0
> y
[1] 2 3 4 5 6 7
> x + y
[1] 4 3 6 5 8 7
> rep(x,3)
[1] 2 0 2 0 2 0
> w
[1]  3.00 -2.00  4.23
> x
[1] 2 0
> x + w
[1]  5.00 -2.00  6.23
Warning message:
In x + w : longer object length is not a multiple of shorter object length
> w
[1]  3.00 -2.00  4.23
> y
[1] 2 3 4 5 6 7
> y[1]
[1] 2
> y[0]
integer(0)
> y[8]
[1] NA
> y[-4]
[1] 2 3 4 6 7
> y[-8]
[1] 2 3 4 5 6 7
> y[c(1,3)]
[1] 2 4
> y[c(1,3,1,3)]
[1] 2 4 2 4
> y[c(1,3,1,3,1,3,1,3,1,3)]
 [1] 2 4 2 4 2 4 2 4 2 4
> z
[1] 1.0 1.5 2.0 2.5 3.0 3.5
> y
[1] 2 3 4 5 6 7
> x
[1] 2 0
> z[y]
[1] 1.5 2.0 2.5 3.0 3.5  NA
> z[x]
[1] 1.5
> x
[1] 2 0
> y[2:4]
[1] 3 4 5
> y
[1] 2 3 4 5 6 7
> y[y>5]
[1] 6 7
> y[y %% 2 == 0]
[1] 2 4 6
> y %% 2 == 0
[1]  TRUE FALSE  TRUE FALSE  TRUE FALSE
> y
[1] 2 3 4 5 6 7
> L <- c(T, F, T, T, T, F)
> y
[1] 2 3 4 5 6 7
> y[L]
[1] 2 4 5 6
> L2 <- c(T,F)
> L2
[1]  TRUE FALSE
> y[L2]
[1] 2 4 6
> y[c(F,T)]
[1] 3 5 7
> y[seq(2,6,by=2)]
[1] 3 5 7
> seq(2,6,by=2)
[1] 2 4 6
> y[-4]
[1] 2 3 4 6 7
> y[-2:4]
Error in y[-2:4] : only 0's may be mixed with negative subscripts
> y[-(2:4)]
[1] 2 6 7
> f <- 1:10
> f
 [1]  1  2  3  4  5  6  7  8  9 10
> f[f %% 3 == 0]
[1] 3 6 9
> f[f %% 3 == 0]
[1] 3 6 9
> # f 2-nél nagyobb, de 8-nál kisebb elemei:
> f[(f>2)&(f<8)]
[1] 3 4 5 6 7
> 0:4
[1] 0 1 2 3 4
> 3^(0:4)
[1]  1  3  9 27 81
> 4*3^(0:4)
[1]   4  12  36 108 324
>