#
# Unit 7 - Vectorization 
#
# Arithmetical and logical operations 
#

# Problem: given a non-empty numeric
# vector vec and a number num, 
# produce a new vector in which 
# num is added to each of vec's values. 
vec <- c(5, 4, 1)
num <- 7 
newVec <- c() 
for (val in vec) {
  newVec <- c(newVec, val + num)
}
print(newVec)


# R offers a shortened code. 
# This is one example for vectorization, 
# specficially: vector with scalar
vec1 <- c(5, 4, 1)
resultVec <- vec1 + 1
print(resultVec)


vec1 <- c(5, 4, 1)
resultVec <- vec1 - 2
print(resultVec)

vec1 <- c(5, 4, 1)
resultVec <- vec1 * 3
print(resultVec)

vec1 <- c(5, 4, 1)
resultVec <- vec1 / 2
print(resultVec)

vec1 <- c(5, 4, 1)
resultVec <- vec1 ^ 2
print(resultVec)



# Problem: given these two vectors 
# produce a new vector which is their
# "sum", namely each value in it is 
# a sum of parallel values in the given 
# vectors. 
vec1 <- c(5, 4, 1)
vec2 <- c(1, 1, 1)
newVec <- c() 
for (ind in 1:length(vec1)) {
  newVec <- c(newVec, vec1[ind] + vec2[ind])
}
print(newVec)



# Using vectorization: 
vec1 <- c(5, 4, 1)
vec2 <- c(1, 1, 1)
resultVec <- vec1 + vec2
print(resultVec)

vec1 <- c(5, 4, 1)
vec2 <- c(1, 1, 1)
resultVec <- vec1 - vec2
print(resultVec)

vec1 <- c(5, 4, 1)
vec2 <- c(1, 1, 1)
resultVec <- vec1 * vec2
print(resultVec)

vec1 <- c(5, 4, 1)
vec2 <- c(1, 1, 1)
resultVec <- vec1 / vec2
print(resultVec)


# Now let us move to logical operations. 
# what would this code do? 
vec1 <- c(TRUE, FALSE, TRUE, TRUE)
vec2 <- c(FALSE, FALSE, TRUE, TRUE)
newVec <- vec1 & vec2 
print(newVec)

print(TRUE & FALSE)

vec1 <- c(TRUE, FALSE, TRUE, TRUE)
vec2 <- c(FALSE, FALSE, TRUE, TRUE)
newVec <- vec1 | vec2 
print(newVec)


vec1 <- c(TRUE, FALSE, TRUE, TRUE)
newVec <- !vec1  
print(newVec)

print(!TRUE)



# %in%, scalar in vector 
vec <- c(1, 4, 1)
print(5 %in% vec)

# %in%, vector in vector 
vec1 <- c(1, 4, 1)
vec2 <- c(1, 1, 1)
result <- vec1 %in% vec2
print(result)