Randomly create some irregular functional data from regular ones.
jiggle it by randomly moving around its arg-values. Only for tfd.
sparsify it by setting (100*dropout)% of its values to NA.
Arguments
- f
 a
tfdobject- amount
 how far away from original grid points can the new grid points lie, at most (relative to original distance to neighboring grid points). Defaults to at most 40% (0.4) of the original grid distances. Must be lower than 0.5
- ...
 additional args for the returned
tfdintf_jiggle- dropout
 how many values of
fto drop, defaults to 50%.