ordering Tests

Description

Tests vectors for (strictly) increasing, decreasing, monotonic and constant properties

Usage

is_constant(x, na.rm = TRUE)

is_increasing(x, na.rm = TRUE)

is_strictly_increasing(x, na.rm = na.omit)

is_decreasing(x, na.rm = na.omit)

is_strictly_decreasing(x, na.rm = na.omit)

is_incremental(x, step = 1, na.rm = TRUE)

is_uniform(x, step = NULL, na.rm = TRUE)

is_monotonic(x, na.rm = TRUE)

is_strictly_monotonic(x, na.rm = TRUE)

is_sorted(x, na.rm = TRUE)

is_strictly_sorted(x, na.rm = TRUE)

is_unsorted(...)

is_strictly_unsorted(...)

Arguments

Details

Tests to various monotone properties of vectors.

is_incremental determines if x is incremental, i.e. monotonic and equally spaced.

is_uniform is a wrapper around is_incremental with step=1

is_[strictly_]monotonic determine the sort properties of x.

This differes from base::is.unsorted() which should more properly be called is.increasing since base::is.unsorted(3:1) == TRUE; 3:1 is obviously sorted.

is_sorted() is a alias for is_monotonic() and is_strictly_sorted() is an alias for is_strictly_monotonic().

Value

logical or NA. (NB: NA is returned because it is a logical vector and this is needed to put these results cleanly in tables.)

logical

Note

The behavior of this package is The functions base::is.unsorted() is perhaps misnamed and should properly be names is_not_increasing since base::is.unsorted(3:1) == TRUE after all vector 3,2,1 is sorted but not increasing.

See Also

• base::diff()

• base::is.unsorted()

Examples

  
  is_constant( rep(3,5) )

  is_increasing( 1:5 )                   # TRUE
  is_increasing( c(1,2,1,3) )            # FALSE
  
  is_increasing( c(1,NA,2,3) )           # NA 
  is_increasing( c(1,NA,2,3), na.omit )  # TRUE

  is_monotonic( 1:5 )                    # TRUE
  is_monotonic( -5:5 )                   # TRUE
  is_monotonic( 5:-5 )                   # TRUE
  is_monotonic( c(1,5,3))                # FALSE
  

  is_incremental(1:5 )
  is_incremental( c(1,2,5))
  
  is_incremental(1:5, step=NULL)
  is_uniform(1:5)


  is_monotonic( 1:3 )
  is_strictly_monotonic(1:3)
  
  is_monotonic( c(1,3,2) )
  is_strictly_monotonic( c(1,3,2) )
  
  is_sorted(1:3)
  is_sorted(c(1,3,2))   
  
  lets <- letters[1:3]
  is_monotonic( lets )
  is_monotonic( c('a', 'c', 'b') )
  
  is_sorted(1:10)
  
  is_sorted(-5:5)
  is_sorted(5:-5)
  
  is_sorted( letters )
  is_sorted( rev(letters) )
  

ordering

Description

Determining the ordering (montonicity) of a vector

Usage

ordering(x, na.rm = TRUE)

monotonicity(x, na.rm = TRUE)

Arguments

Details

monotonicty determines the monotonicy (first derivative) of a numeric vector as one of:

• stictly increasing,

• increasing / montonically increasing / non-decreasing,

• decreasing / monotonically decreasing / non-increasing,

• strictly decreasing, or

• constant

ordering tests, e.g. is_increasing are more efficient at testing.

monotonicity() is an alias for ordering.

Value

integer;

• 2 : stictly increasing

• 1 : increasing / montonically increasing / non-decreasing

• 0 : non-ordered or constant

• -1: decreasing / monotonically decreasing / non-increasing

• -2: strictly decreasing

• NA:contains onlyNAs all na.rmdid not resolve allNA's

References

http://en.wikipedia.org/wiki/Monotonic_function http://stackoverflow.com/questions/13093912/how-to-check-if-a-sequence-of-numbers-is-monotonically-increasing-or-decreasing

Examples

  ordering( 1:3 )      # 2  
  ordering( c(1,1,3) ) # 1 
  ordering( c(1,0,1) ) # 0  "No ordering, does not apply constant"
  ordering( c(3,1,1) ) # -1
  ordering( 3:1 )      # -2