Q1

NT_CVT_US<- function() {
  M<- readline(prompt="NT:")
cat("US:$",as.numeric(M)/29.32,"", sep = "")
}
NT_CVT_US()
## NT:
## US:$NA

Q2

library(datasets)
dta2<-ChickWeight
head(dta2)
## Grouped Data: weight ~ Time | Chick
##   weight Time Chick Diet
## 1     42    0     1    1
## 2     51    2     1    1
## 3     59    4     1    1
## 4     64    6     1    1
## 5     76    8     1    1
## 6     93   10     1    1
str(dta2)
## Classes 'nfnGroupedData', 'nfGroupedData', 'groupedData' and 'data.frame':   578 obs. of  4 variables:
##  $ weight: num  42 51 59 64 76 93 106 125 149 171 ...
##  $ Time  : num  0 2 4 6 8 10 12 14 16 18 ...
##  $ Chick : Ord.factor w/ 50 levels "18"<"16"<"15"<..: 15 15 15 15 15 15 15 15 15 15 ...
##  $ Diet  : Factor w/ 4 levels "1","2","3","4": 1 1 1 1 1 1 1 1 1 1 ...
##  - attr(*, "formula")=Class 'formula'  language weight ~ Time | Chick
##   .. ..- attr(*, ".Environment")=<environment: R_EmptyEnv> 
##  - attr(*, "outer")=Class 'formula'  language ~Diet
##   .. ..- attr(*, ".Environment")=<environment: R_EmptyEnv> 
##  - attr(*, "labels")=List of 2
##   ..$ x: chr "Time"
##   ..$ y: chr "Body weight"
##  - attr(*, "units")=List of 2
##   ..$ x: chr "(days)"
##   ..$ y: chr "(gm)"
sapply(split(dta2,dta2$Chick),  
       function(x) lm(weight ~Time, data = x)$coef)
##             18        16       15        13         9        20        10
## (Intercept) 39 43.392857 46.83333 43.384359 52.094086 37.667826 38.695054
## Time        -2  1.053571  1.89881  2.239601  2.663137  3.732718  4.066102
##                     8        17       19        4         6        11
## (Intercept) 43.727273 43.030706 31.21222 32.86568 44.123431 47.921948
## Time         4.827273  4.531538  5.08743  6.08864  6.378006  7.510967
##                    3         1        12         2        5       14
## (Intercept) 23.17955 24.465436 21.939797 24.724853 16.89563 20.52488
## Time         8.48737  7.987899  8.440629  8.719861 10.05536 11.98245
##                     7        24        30        22        23        27
## (Intercept)  5.842535 53.067766 39.109666 40.082590 38.428074 29.858569
## Time        13.205264  1.207533  5.898351  5.877931  6.685978  7.379368
##                    28       26       25        29       21        33
## (Intercept) 23.984874 20.70715 19.65119  5.882771 15.56330 45.830283
## Time         9.703676 10.10316 11.30676 12.453487 15.47512  5.855241
##                    37       36       31       39       38       32
## (Intercept) 29.608834 25.85403 19.13099 17.03661 10.67282 13.69173
## Time         6.677053  9.99047 10.02617 10.73710 12.06051 13.18091
##                   40        34        35        44        45        43
## (Intercept) 10.83830  5.081682  4.757979 44.909091 35.673121 52.185751
## Time        13.44229 15.000151 17.258811  6.354545  7.686432  8.318863
##                    41        47        49        46       50       42
## (Intercept) 39.337922 36.489790 31.662986 27.771744 23.78218 19.86507
## Time         8.159885  8.374981  9.717894  9.738466 11.33293 11.83679
##                    48
## (Intercept)  7.947663
## Time        13.714718

Q3

L<- function(df){
  curve(dnorm(x),-4,4,col= 2, ylab = "dnorm(x)", lwd = 2)
  for(i in 1:length(df))curve(dt(x,df[[i]]),col=3,lty=2,add=TRUE)
}
L(df=1:32)

Q4

library(pacman)

pacman::p_load(MASS, tidyverse)
# method 1 #做法簡單

aggregate( . ~ Type, data = Cushings, mean)
##   Type Tetrahydrocortisone Pregnanetriol
## 1    a            2.966667          2.44
## 2    b            8.180000          1.12
## 3    c           19.720000          5.50
## 4    u           14.016667          1.20
# method 2 # wide format

sapply(split(Cushings[,-3], Cushings$Type), function(x) apply(x, 2, mean))
##                            a    b     c        u
## Tetrahydrocortisone 2.966667 8.18 19.72 14.01667
## Pregnanetriol       2.440000 1.12  5.50  1.20000
# method 3 #long format

do.call("rbind", as.list(
  by(Cushings, list(Cushings$Type), function(x) {
    y <- subset(x, select =  -Type)
    apply(y, 2, mean)
  }
)))
##   Tetrahydrocortisone Pregnanetriol
## a            2.966667          2.44
## b            8.180000          1.12
## c           19.720000          5.50
## u           14.016667          1.20
# method 4 #使用dplyr裡面的pipe功能,快速分組運算

Cushings %>%
 group_by(Type) %>%
 summarize( t_m = mean(Tetrahydrocortisone), p_m = mean(Pregnanetriol))
## # A tibble: 4 x 3
##   Type    t_m   p_m
##   <fct> <dbl> <dbl>
## 1 a      2.97  2.44
## 2 b      8.18  1.12
## 3 c     19.7   5.50
## 4 u     14.0   1.20
# method 5 #查看資料屬性

Cushings %>%
 nest(-Type) %>%
 mutate(avg = map(data, ~ apply(., 2, mean)), 
        res_1 = map_dbl(avg, "Tetrahydrocortisone"), 
        res_2 = map_dbl(avg, "Pregnanetriol")) 
## Warning: package 'bindrcpp' was built under R version 3.4.4
## # A tibble: 4 x 5
##   Type  data                  avg       res_1 res_2
##   <fct> <list>                <list>    <dbl> <dbl>
## 1 a     <data.frame [6 × 2]>  <dbl [2]>  2.97  2.44
## 2 b     <data.frame [10 × 2]> <dbl [2]>  8.18  1.12
## 3 c     <data.frame [5 × 2]>  <dbl [2]> 19.7   5.50
## 4 u     <data.frame [6 × 2]>  <dbl [2]> 14.0   1.20

Q5

K<- function(n,mu,sigm){
  set.seed(0221)
  sample<-rnorm(n,mu,sigm)
  plot(x = 1:n, y = cumsum(sample)/1:n, type = "l", col = 3,
       xlab = "Sample Size", ylab = "Running Average")
  abline(h = mu, col = 2, lty = 2)
}
#EX
K(3000,20,10)

Q6

setwd("/Users/tayloryen/Desktop/大學/成大課業/大四下/資料管理/0409/HW")
dta6<-read.table("q6.txt", header=T)
# function
c.stat <- function(data, n = length(data)){
  cden <- 1-(sum(diff(dta6[1:n,1])^2)/(2*(n-1)*var(dta6[1:n,1])))
  sc <- sqrt((n-2)/((n-1)*(n+1)))
  pval <- 1-pnorm(cden/sc)
  return(list(c=cden,z=cden/sc,pvalue=pval))
}

c.stat(dta6,36) 
## $c
## [1] 0.660105
## 
## $z
## [1] 4.073882
## 
## $pvalue
## [1] 2.311794e-05

Q7

library(rgl)
## Warning: package 'rgl' was built under R version 3.4.4
knitr::knit_hooks$set(webgl = hook_webgl)
dta <- read.table("q7.txt", header = TRUE)

ssq <- function(mu, sigma, y) {sum(((y - mu) / sigma)^2)}
vssq <- Vectorize(ssq, c("mu", "sigma"))

RR<- function(data = NA){
  x <- seq(mean(data) - 5, mean(data) + 5, by = 0.1)
  y <- sd(data)
  z <- vssq(x, sd(data), data)
  rgl::plot3d(x, y, z, 
              xlab = "mu", ylab = "sigma(control)", zlab = "ssq")
}

##The End
RR(data=dta$math)

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