exists function on list objects gives always a FALSE

SmoothData <- list(exists=TRUE, span=0.001)
SmoothData
    

$exists
[1] TRUE

$span
[1] 0.001

  

exists("SmoothData")
    

TRUE

  

exists("SmoothData$span")
    

FALSE

  

'SmoothData$span' = 'foo'
    exists("SmoothData$span")
    # TRUE

exists("SmoothData[[2]]")
    

'SmoothData[[2]]' = 'bar'
    exists("SmoothData[[2]]")
    # TRUE


the problem in your case is that you have an object named 'SmoothData'
with a nested component named 'span', but you're testing for the
existence of an object named 'SmoothData$span'. 

as shown in a recent post, one attempt to do your task would be

    exists('SmoothData') && 'span' %in% names(SmoothData)
    # TRUE

vQ