2020-03-16 Homework 4-5

Homework 4 US Births at 2015

讀取資料 usBirths2015

dta <- read.table("C:/Users/X510/Desktop/2020-03-16 Homework 4-5/usBirths2015.txt", header = T)
dta

##     birth     month
## 1  325955   January
## 2  298058  February
## 3  328923     March
## 4  320832     April
## 5  327917       May
## 6  330541      June
## 7  353415      July
## 8  351791    August
## 9  347516 September
## 10 339007   October
## 11 318820  November
## 12 335722  December

依季節重新命名月份

dta$month <- c("spring", "spring", "spring", "summer", "summer", "summer", "autumn", "autumn", "autumn", "winter", "winter", "winter")

各季節誕生嬰兒總數

dta

##     birth  month
## 1  325955 spring
## 2  298058 spring
## 3  328923 spring
## 4  320832 summer
## 5  327917 summer
## 6  330541 summer
## 7  353415 autumn
## 8  351791 autumn
## 9  347516 autumn
## 10 339007 winter
## 11 318820 winter
## 12 335722 winter

aggregate(birth ~ month, sum, data=dta)

##    month   birth
## 1 autumn 1052722
## 2 spring  952936
## 3 summer  979290
## 4 winter  993549

Homework 5 Reading

讀取資料 usBirths2015

dta <- read.table("C:/Users/X510/Desktop/2020-03-16 Homework 4-5/readingtimes.txt", header = T)
dta

##   Snt Sp Wrds New   S01   S02   S03   S04   S05    S06    S07   S08   S09   S10
## 1   1  1   13   1 3.429 2.795 4.161 3.071 3.625  3.161  3.232 7.161 1.536 4.063
## 2   2  2   16   3 6.482 5.411 4.491 5.063 9.295  5.643  8.357 4.313 2.946 6.652
## 3   3  3    9   2 1.714 2.339 3.018 2.464 6.045  2.455  4.920 3.366 1.375 2.179
## 4   4  4    9   2 3.679 3.714 2.866 2.732 4.205  6.241  3.723 6.330 1.152 3.661
## 5   5  5   10   3 4.000 2.902 2.991 2.670 3.884  3.223  3.143 6.143 2.759 3.330
## 6   6  6   18   4 6.973 8.018 6.625 7.571 8.795 13.188 11.170 6.071 7.964 7.866
## 7   7  7    6   1 2.634 1.750 2.268 2.884 3.491  3.688  2.054 1.696 1.455 3.705

S01~S10閱讀耗費總時間以及排序

dta01 <- sum(dta$S01)
dta01

## [1] 28.911

dta02 <- sum(dta$S02)
dta02

## [1] 26.929

dta03 <- sum(dta$S03)
dta03

## [1] 26.42

dta04 <- sum(dta$S04)
dta04

## [1] 26.455

dta05 <- sum(dta$S05)
dta05

## [1] 39.34

dta06 <- sum(dta$S06)
dta06

## [1] 37.599

dta07 <- sum(dta$S07)
dta07

## [1] 36.599

dta08 <- sum(dta$S08)
dta08

## [1] 35.08

dta09 <- sum(dta$S09)
dta09

## [1] 19.187

dta10 <- sum(dta$S10)
dta10

## [1] 31.456

x <- c(dta01, dta02, dta03, dta04, dta05, dta06, dta07, dta08, dta09, dta10)
order(x)

##  [1]  9  3  4  2  1 10  8  7  6  5

S01~S10平均閱讀一個字所需的時間

w <- sum(dta$Wrds)
w

## [1] 81

x <- c(dta01/w, dta02/w, dta03/w, dta04/w, dta05/w, dta06/w, dta07/w, dta08/w, dta09/w, dta10/w)
x

##  [1] 0.3569259 0.3324568 0.3261728 0.3266049 0.4856790 0.4641852 0.4518395
##  [8] 0.4330864 0.2368765 0.3883457