rm(list=ls(all=TRUE))
#Function

a <- c(1, 2, 3, 4, 5, 6, 7, 8)
b = 5
xmean <- function(x){
  y <- sum(x)/length(x)
  z <- y/5
  return(z)
}

xmean(a)

#Function to sum 2 values
myFunc1 <- function(a,b){ #starts with curly bracket
  c <- a+b
  return(c)
} #ends with curly bracket

myFunc1(5, 6)#call the function and send 2 values

myFunc1 <- function(a){ #starts with curly bracket
  c <- sum(a)
  l <- length(a)
  d <- c/l
  return(d)
} #ends with curly bracket



# another function to return values between a range
myFunc2 <- function(v,x,z){
  s <- v[v>x] 
  s <- s[s<z] 
  return(s)
}

d <- c(20:30) #set the list of values for v

myFunc2(d, 22, 27) #call the function and send 1 vector and 2 values

# to debug and test
myFunc2 <- function(v,MinVal, MaxVal){
  s <- v[v>MinVal] 
  cat("This is 1st s:", s, "\n")
  
  s <- s[s<MaxVal] 
  cat("This is 2nd s:", s, "\n")
  return(s)
}
myFunc2(d, 10, 29)

#you can call all your codes outside of the function before running the finction to make sure and see your results

#find the car with max hp
myFunc3 <- function(a, b){
  index <- which.max(a)
  rnames <- rownames(b)
  car <- rnames[index] 
  return(car)
}

myFunc3(mtcars$cyl, mtcars)


#function for weight and hight
myFunc4 <- function(x, y){
  newWeight <- x+5
  Calculate <- newWeight/y
  return(Calculate)
  }

z <- c(59,60,61,58,67,72,70)
b <- c(150,140,180,220,160,140,130)

myFunc4(z, b)            
       
myFunc5 <- function(a,b){
  c<-length(a[a>b])
  e<-c/length(a)
  # Question 11: The function will return the percentage of elements in vector more than the number
  return(e)
}

myFunc5 <- function(a){
  c<-length(a)
  d<-sum(a)
  e <- d/c
  return(e)
}

myFunc5(z, 69)

# Question 12: Vector has 5 elements, the number passed into the function is 2, result is 0.2
TestingVector <- 1
num <- 2
myFunc5(1,2)

#HW3 Framework

testFrame <- read.csv(url("http://www2.census.gov/programs-surveys/popest/tables/2010-2011/state/totals/nst-est2011-01.csv"))
str(testFrame)
head(testFrame, 1)
View(testFrame)

testFrame <- testFrame[-1:-8,]
rownames(testFrame) <- NULL
testFrame <- testFrame[-52:-80,]
testFrame <- testFrame[,-6:-10]
# ----------------Rename Rows and Columns
# ----Renumber the rownames
rownames(testFrame) <- NULL

# ----Renumber the column names
colnames(testFrame) <- c("Name", "X","","","")

testFrame

# Eliminate periods in state names
testFrame$Name <- gsub("\\.","",testFrame$Name)

# Clean up population data (remove commas), should be applied to some columns
testFrame$X <- gsub("\\,", "", testFrame$X)
testFrame$X <- as.numeric(testFrame$X)
str(testFrame)

# Step 7 has incorrect mean in the HW