My question is related to calculate the multiplies of 12 (factorials) in a for loop:

I spent a lot of time on this but can`t solve it!

It is important to use a function with a 'for' loop!

So far: I had tried doing

for(i in 1:12){
   prod(i)
}

and also

for(i in 1:12){
   print(prod(i)
}

and also

for(i in 1:12){
   prod(i)
}

and also

for(i in 1:12){
   print(prod(i)
}

and also

many other code, and it does not work

CodePudding user response：

For:

my_factorial<-function(x){
  y<-1
  for(i in 1:x) {
    y<-y*((1:x)[i])
  }
  return(y) 
}
my_factorial(12)

is the same as:

factorial

factorial(12)

OR You can use gamma for factorials:

x = 12
gamma(x 1)

is the same as:

12*11*10*9*8*7*6*5*4*3*2*1
[1] 479001600

result:

[1] 479001600

CodePudding user response：

If you want product of first numbers at each iteration

b=vector()
for (i in 1:12){
  b[i]=i
  print(prod(b))
}

[1] 1
[1] 2
[1] 6
[1] 24
[1] 120
[1] 720
[1] 5040
[1] 40320
[1] 362880
[1] 3628800
[1] 39916800
[1] 479001600

This will be like

1
1*2
1*2*3
.
.
.
1*2*3*4*5*6*7*8*9*10*11*12

But if you want just the product of the 12 first positive integers then you do not need a for loop. just use product function.

prod(1:12)
[1] 479001600