Pattern Drawing in R

Everyone found an easy way for pattern printing in other programming languages. But its a tough task using R language . This article focuses on drawing various patterns using R language and its constructs.

Approach

• Start first loop for number of lines
• Start second loop for item to be displayed
• Print item
• Increment second loop until a condition is reached
• Increment first loop until condition is true
• Continue in this fashion

Program 1: Drawing a Triangle with numbers

R

stars = c()

for(i in 1:5){
  for(j in 1:i+1){
     stars = c(stars, i)
  }

  print(stars)
  stars = c()
}

Output:

[1] 1
[1] 2 2
[1] 3 3 3
[1] 4 4 4 4
[1] 5 5 5 5 5

Program 2: Drawing a triangle with *

R

#creating a empty list to store
stars = c()

for(i in 1:5){
   for(j in 1:i+1){
      stars = c(stars, "*")
   }
  # line by line printing
  print(stars)
  stars = c()
}

Output:

[1] "*"
[1] "*" "*"
[1] "*" "*" "*"
[1] "*" "*" "*" "*"
[1] "*" "*" "*" "*" "*"

Program 3: Draw inverted triangle

R

starsrev = c()
i=1
j=5

while(i<=5){
  for(j in 1:j){
     starsrev = c(starsrev, "*")
   }

  print(starsrev)

  starsrev = c()

  i=i+1
  j=j-1
}

Output:

[1] "*" "*" "*" "*" "*"
[1] "*" "*" "*" "*"
[1] "*" "*" "*"
[1] "*" "*"
[1] "*"

Program 4: Drawing inverted as well as normal triangle pattern

R

i=1
stars = c()

while(i<=5){
  for(j in 1:i+1){
     stars = c(stars, "*")
  }

  print(stars)
  stars = c()
  i=i+1
}

starsrev = c()
i=1
j=5

while(i<=5){
  for(j in 1:j){
    starsrev = c(starsrev, "*")
  }

  print(starsrev)
  starsrev = c()
  i=i+1
  j=j-1
}

Output:

[1] "*"
[1] "*" "*"
[1] "*" "*" "*"
[1] "*" "*" "*" "*"
[1] "*" "*" "*" "*" "*"
[1] "*" "*" "*" "*" "*"
[1] "*" "*" "*" "*"
[1] "*" "*" "*"
[1] "*" "*"
[1] "*"