xBarGenerator code giving me an error in RStudio

[Prinbun]

I am getting an error while trying this. I also tried installing the qcc package and sued process.capability() but I am still getting an error. Can anyone help? Here is my code:

# Arguments: samplesize: the size of the sample that each sample mean is based on. 
# number_of_samples: the number of samples and thus sample means we will #generate

xbarGenerator = function(sampleSize = 30,number_of_samples = 100)
{
  for(i in 1:number_of_samples)
  {
    theSample = sample(population,sampleSize)
    xbar = mean(theSample)
    xBarVec = c(xBarVec, xbar)
  }
  return(xBarVec)
}

xbars = xbarGenerator(30,1000)
length(xbars)
hist(xbars)

The output I am getting is below:
> xbarGenerator = function(sampleSize = 30,number_of_samples = 100)
+ {
+   for(i in 1:number_of_samples)
+   {
+     theSample = sample(population,sampleSize)
+     xbar = mean(theSample)
+     xBarVec = c(xBarVec, xbar)
+   }
+   return(xBarVec)
+ }
xbars = xbarGenerator(30,1000)
Error in xbarGenerator(30, 1000) : object 'xBarVec' not found
> length(xbars)
Error: object 'xbars' not found
> hist(xbars)
Error in hist(xbars) : object 'xbars' not found
>

[andresrcs]

Can you be more specific? what is the error message you are getting? what is your expected output?
Also, please turn this into a proper REPRoducible EXample (reprex), right now we can't reproduce your code since you are not showing what population is or from where it comes from.

[Prinbun]

Hi, the population is coming from this code:
xBarVec = c() #Global vector to hold the sample means
population = rnorm(10000000,0,1) #Simulating the population

[andresrcs]

@Prinbun

xBarVec = c() #Global vector to hold the sample means
population = rnorm(10000000,0,1) #Simulating the population

Well, you just have to add those lines to your function and it works

xbarGenerator = function(sampleSize = 30,number_of_samples = 100) {
    population = rnorm(10000000,0,1)
    xBarVec = c()
    for(i in 1:number_of_samples) {
        theSample = sample(population,sampleSize)
        xbar = mean(theSample)
        xBarVec = c(xBarVec, xbar)
    }
    return(xBarVec)
}

xbars = xbarGenerator(30,1000)
length(xbars)
#> [1] 1000
hist(xbars)

^{Created on 2020-01-07 by the reprex package (v0.3.0.9000)}