results
results[2]
rm( results )
ls()
results[ 1 ] <- "a"
ls()
results <- c("a","b","c")
results
results <- NULL
results[ 1 ] <- "a"
results[ 2 ] <- "b"
results[ 3 ] <- "c"
results
2^1
2^2
2^3
2^4
2^5
results <- NULL
for( i in 1:5 )
{
  results[i] <- 2^i   
}
results
for( i in c("a","b","c") )
{
  print( i )   
}
results <- NULL
results[ 1 ] <- "a"
results[ 2 ] <- "b"
results[ 3 ] <- "c"
results
length(results)
results
results["a"]
results[1]
results[c(1,3)]
results[c(T,F,T)]
results <- NULL
for( i in 7:8 )
{
  results[i] <- 2^i   
}
results
2&7
2^7
2^8
results <- NULL
for( i in c(1,7:8) )
{
  results[i] <- 2^i   
}
results
results <- NULL
results[1] <- 2^1
results
class(results)
length(results)
results <- NULL
for( i in c(1,7:8) )
{
  results[i] <- 2^i   
}
results
mean( results )
mean( results, na.rm=T )
sum(results,na.rm=T)/length(results)
x <- c(1,7:8)
1:length(x)
results <- NULL
x <- c(1,7:8)
for( i in 1:length(x) )
{
  results[i] <- 2^i   
}
results
x
results <- NULL
x <- c(1,7:8)
for( i in 1:length(x) )
{
  results[i] <- 2^x   
}
x[1]
x[2]
x[3]
results <- NULL
results[1] <- 2^x[1]
results[2] <- 2^x[2] 
results[3] <- 2^x[3]
results
results <- NULL
x <- c(1,7:8)
for( i in 1:length(x) )
{
  results[i] <- 2^x[i]   
}
results
results <- NULL
x <- c("a","b","c")
for( i in 1:length(x) )
{
  results[ i ] <- x[1]  
}
results
LETTERS
letters
results <- NULL
for( i in 1:500 )
{
  results[ i ] <- sample( LETTERS, size=1 )  
}
table( results )
results <- NULL
for( i in 1:500 )
{
  results[ i ] <- sample( LETTERS[10], size=1 )  
}
table( results )
results <- NULL
for( i in 1:500 )
{
  results[ i ] <- sample( LETTERS[1:10], size=1 )  
}
table( results )
results <- list()
results
results <- character(3)
results
results <- numeric(3)
results
results <- list(3)
results
ls()
character(3)
numeric(3)
numeric(8)
results <- list()
for( i in 1:3 )  # I LOOP
{
  for( j in 1:4 )  # J LOOP
  {
     car.position <- i
     first.pick <- j
     choice.combinations <- c( car.position, first.pick )
     print( choice.combinations )
  }
}
for( i in 1:3 )  # I LOOP
{
  for( j in 1:4 )  # J LOOP
  {
     car.position <- i
     first.pick <- j
     choice.combinations <- c( car=car.position, pick=first.pick )
     print( choice.combinations )
  }
}
results <- list()
loop.count <- 1
for( i in 1:3 )  # I LOOP
{
  for( j in 1:4 )  # J LOOP
  {
     car.position <- i
     first.pick <- j
     choice.combinations <- c( car=car.position, pick=first.pick )
     results[[ loop.count ]] <- choice.combinations 
     loop.count <- loop.count + 1
  }
}
results
feed_pig <- function( weight )
{  
   new.weight <- weight + 1
   return( new.weight ) 
}
current.pig.weight <- 100
current.pig.weight <- 100
# history of weights 
old.weight <- pig.weight
loop.count <- 1
while( current.pig.weight < 200 )
{
  new.weight <- feed_pig( pig.weight )
  old.weight <- c( old.weight, new.weight )
  current.pig.weight <- new.weight
  # to see data while loop is running 
  # print( pig.weight )
}
# history of weights 
old.weight <- pig.weight
loop.count <- 1
while( current.pig.weight < 200 )
{
  new.weight <- feed_pig( pig.weight )
  old.weight <- c( old.weight, new.weight )
  current.pig.weight <- new.weight
  # to see data while loop is running 
  # print( pig.weight )
}
pig.weight <- 100
# history of weights 
old.weight <- pig.weight
loop.count <- 1
while( current.pig.weight < 200 )
{
  new.weight <- feed_pig( pig.weight )
  old.weight <- c( old.weight, new.weight )
  current.pig.weight <- new.weight
  # to see data while loop is running 
  # print( pig.weight )
}
current.pig.weight
feed_pig <- function( weight )
{  
   new.weight <- weight + 1
   return( new.weight ) 
}
pig.weight <- 100
feed_pig <- function( weight )
{  
   new.weight <- weight + 1
   return( new.weight ) 
}
pig.weight <- 100
# history of weights 
old.weight <- pig.weight
loop.count <- 1
while( pig.weight < 200 )
{
  pig.weight <- feed_pig( pig.weight )
  old.weight <- c( old.weight, pig.weight )
  # to see data while loop is running 
  print( pig.weight )
}
pig.weight <- 100
old.weight <- pig.weight  # save history of weights 
while( pig.weight < 200 )
{
  pig.weight <- feed_pig( pig.weight )
  old.weight <- c( old.weight, pig.weight )
  print( pig.weight ) # preview current weight
}
# pig gains 1 lb each day
feed_pig <- function( weight )
{  
   new.weight <- weight + 1
   return( new.weight ) 
}
rnorm(1)
args( rnorm )
feed_pig <- function( weight )
{  
   new.weight <- weight + rnorm( n=1, mean=1, sd=1 )
   return( new.weight ) 
}
pig.weight <- 100
for( i in 1:5 )
{
  pig.weight <- feed.pig( pig.weight )
  print( pig.weight )
}
pig.weight <- 100
for( i in 1:5 )
{
  pig.weight <- feed_pig( pig.weight )
  print( pig.weight )
}
pig.weight <- 100
for( i in 1:100 )
{
  pig.weight <- feed_pig( pig.weight )
}
pig.weight 
pig.weight <- 100
day.count <- 1
while( pig.weight < 200 )
{
  pig.weight <- feed_pig( pig.weight )
  day.count <- day.count + 1
}