ILLUSTRATUION OF MISCELLANEOUS COMMANDS            8/30/2017
============================================================

> paste(letters[1:8],1:8,sep=".")
[1] "a.1" "b.2" "c.3" "d.4" "e.5" "f.6" "g.7" "h.8"

> paste(letters[1:8], collapse="")
[1] "abcdefgh"
> strsplit(.Last.value,"")
[[1]]
[1] "a" "b" "c" "d" "e" "f" "g" "h"
> unlist(.Last.value)
[1] "a" "b" "c" "d" "e" "f" "g" "h"

> length("abcdefgh")
[1] 1
> nchar("abcdefgh")
[1] 8

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> if(3<5) 1:5  else  10:15
[1] 1 2 3 4 5

>  ifelse( (1:10) %% 2 , 1:10, 11:20 )
 [1]  1 12  3 14  5 16  7 18  9 20

> replace(1:10, (1:10 %% 2)==0, 11:20)
 [1]  1 11  3 12  5 13  7 14  9 15
Warning message:
In x[list] <- values :
  number of items to replace is not a multiple of replacement length

-------------------------------------
 
> tmplist = NULL
  for(i in 1:5) tmplist = c(tmplist, list(1:i))
  
>  tmplist
[[1]]
[1] 1

[[2]]
[1] 1 2

[[3]]
[1] 1 2 3

[[4]]
[1] 1 2 3 4

[[5]]
[1] 1 2 3 4 5

> unlist(tmplist)
[1] 1 1 2 1 2 3 1 2 3 4 1 2 3 4 5

--------------------------------------

> tmp = table(rpois(100,2))
> attributes(tmp)
$dim
[1] 8

$dimnames
$dimnames[[1]]
[1] "0" "1" "2" "3" "4" "5" "6" "7"


$class
[1] "table"

---------------------------------------

> outer(1:5, (-2):2, "+")
     [,1] [,2] [,3] [,4] [,5]
[1,]   -1    0    1    2    3
[2,]    0    1    2    3    4
[3,]    1    2    3    4    5
[4,]    2    3    4    5    6
[5,]    3    4    5    6    7

> attributes(.Last.value)
$dim
[1] 5 5

> c(outer(1:5, (-2):2, "+"))
[1] -1  0  1  2  3  0  1  2  3  4  1  2  3  4  5  2  3  4  5  6  3  4  5  6  7

> outer(1:5, (-2):2, "*")
     [,1] [,2] [,3] [,4] [,5]
[1,]   -2   -1    0    1    2
[2,]   -4   -2    0    2    4
[3,]   -6   -3    0    3    6
[4,]   -8   -4    0    4    8
[5,]  -10   -5    0    5   10

> outer(letters[1:5], 3:7, paste, sep=".")
     [,1]  [,2]  [,3]  [,4]  [,5] 
[1,] "a.3" "a.4" "a.5" "a.6" "a.7"
[2,] "b.3" "b.4" "b.5" "b.6" "b.7"
[3,] "c.3" "c.4" "c.5" "c.6" "c.7"
[4,] "d.3" "d.4" "d.5" "d.6" "d.7"
[5,] "e.3" "e.4" "e.5" "e.6" "e.7"


---------------------------------------

> x = 1:10
> y = 3:17
> z = 4:6

> x[] = y[]
Warning message:
In x[] = y[] :
  number of items to replace is not a multiple of replacement length
> x
 [1]  3  4  5  6  7  8  9 10 11 12

> x[] = z[]
Warning message:
In x[] = z[] :
  number of items to replace is not a multiple of replacement length
> x
 [1] 4 5 6 4 5 6 4 5 6 4

> x = z
> x
[1] 4 5 6


---------------------------------------------

> tmpmat = array(sample(100, 25), c(5,5))
> tmpmat
     [,1] [,2] [,3] [,4] [,5]
[1,]    5   13   19   76   58
[2,]   98   41   83   96   47
[3,]   55   50   67   95   88
[4,]   86   89   61   80    7
[5,]   78   16   28   17   97

> mean(tmpmat)
[1] 58

> apply(tmpmat,2,mean)
[1] 64.4 41.8 51.6 72.8 59.4

> summary(tmpmat)
       V1             V2             V3             V4             V5      
 Min.   : 5.0   Min.   :13.0   Min.   :19.0   Min.   :17.0   Min.   : 7.0  
 1st Qu.:55.0   1st Qu.:16.0   1st Qu.:28.0   1st Qu.:76.0   1st Qu.:47.0  
 Median :78.0   Median :41.0   Median :61.0   Median :80.0   Median :58.0  
 Mean   :64.4   Mean   :41.8   Mean   :51.6   Mean   :72.8   Mean   :59.4  
 3rd Qu.:86.0   3rd Qu.:50.0   3rd Qu.:67.0   3rd Qu.:95.0   3rd Qu.:88.0  
 Max.   :98.0   Max.   :89.0   Max.   :83.0   Max.   :96.0   Max.   :97.0  




> c(tmpmat %*% rep(0.2,5))
[1] 34.2 73.0 71.0 64.6 47.2
> apply(tmpmat,1,mean)
[1] 34.2 73.0 71.0 64.6 47.2