class555.R

##租借MASS資料庫
library(MASS)
##發展MASS資料庫
pacman::p_load(MASS)
##了解Animals、mammals資料型態
class(Animals)

## [1] "data.frame"

names(Animals)

## [1] "body"  "brain"

dim(Animals)

## [1] 28  2

class(mammals)

## [1] "data.frame"

names(mammals)

## [1] "body"  "brain"

dim(mammals)

## [1] 62  2

##關鍵發展Animals、mammals資料指令
dtaA<- MASS::Animals
dtaM<- MASS::mammals
head(dtaA)

##                     body brain
## Mountain beaver     1.35   8.1
## Cow               465.00 423.0
## Grey wolf          36.33 119.5
## Goat               27.66 115.0
## Guinea pig          1.04   5.5
## Dipliodocus     11700.00  50.0

head(dtaM)

##                    body brain
## Arctic fox        3.385  44.5
## Owl monkey        0.480  15.5
## Mountain beaver   1.350   8.1
## Cow             465.000 423.0
## Grey wolf        36.330 119.5
## Goat             27.660 115.0

##合併資料並用duplicated刪除重複值，FALSE代表沒有重複值
dtaC<- merge(dtaA, dtaM, all = T)
duplicated(dtaC$body)

##  [1] FALSE FALSE FALSE  TRUE FALSE FALSE FALSE FALSE FALSE FALSE FALSE FALSE
## [13] FALSE FALSE FALSE FALSE FALSE FALSE FALSE FALSE FALSE FALSE FALSE FALSE
## [25] FALSE FALSE FALSE FALSE FALSE FALSE FALSE FALSE FALSE  TRUE FALSE FALSE
## [37] FALSE FALSE FALSE FALSE FALSE FALSE FALSE FALSE FALSE FALSE FALSE FALSE
## [49] FALSE FALSE FALSE FALSE FALSE FALSE FALSE FALSE FALSE FALSE FALSE FALSE
## [61] FALSE FALSE FALSE FALSE FALSE

##檢查合併後結果
head(dtaC)

##    body brain
## 1 0.005  0.14
## 2 0.010  0.25
## 3 0.023  0.30
## 4 0.023  0.40
## 5 0.048  0.33
## 6 0.060  1.00

###附贈播放音樂code
getwd()

## [1] "C:/tmp"

library(tuneR)
track1 <- readMP3("C:/tmp/pri.mp3")
track1

## 
## Wave Object
##  Number of Samples:      23583744
##  Duration (seconds):     534.78
##  Samplingrate (Hertz):   44100
##  Channels (Mono/Stereo): Stereo
##  PCM (integer format):   TRUE
##  Bit (8/16/24/32/64):    16

play(track1)