manual:chapter6:lists:cmd_deltalist

Synopsis


Return first differences of elements of a list

Stack Diagram


Input Stack Output Stack
Ldata Ldiff
Level 1 Level 1

Legend

Keyword type Command
Parallel list processing capabilities Group 2 Commands that must use DOLIST to parallel process
Affected by flags None

Description


The ΔLIST command returns the first differences of the elements in the list Ldata, i.e.: $$ data_2-data_1 \\ data_3-data_2 \\ data_4-data_3 \\ \ldots $$ The list must contain at least two elements, and the elements themselves must be suitable for mutual subtraction.

Compatibility


ΔLIST is fully equivalent to its userRPL counterpart.

Usage


Input

4:                                      
3:                                      
2:                                      
1:                  { 39 18 5 '2*X' 73 }
…………………………………………………………………………………………………………
ΔLIST                                   


Output

4:                                      
3:                                      
2:                                      
1:          { -21 -13 '2*X-5' '73-2*X' }
…………………………………………………………………………………………………………
                                        

Related Commands


Operations with Lists 15 2 NEW

Command Short Description
→LIST Assemble a list from its elements
LIST→ Split a list into its elements
DOLIST Do a procedure with elements of lists CHANGED
DOSUBS Do a procedure on a subset of a list CHANGED
MAP Do a procedure on each element of a list, recursively
MAPLIST→ Do a procedure on each element recursively, return individual elements NEW
STREAM Do a procedure on consecutive elements of a list
ΔLIST First differences on the elements of a list
ΣLIST Sum of all elements in a list CHANGED
ΠLIST Product of all elements in a list CHANGED
ADD Concatenate lists and/or elements CHANGED
SORT Sort elements in a list
REVLIST Reverse the order of elements in a list
ADDROT Add elements to a list, keep only the last N elements NEW
SEQ Assemble a list from results of sequential procedure
  • manual/chapter6/lists/cmd_deltalist.txt
  • Last modified: 2021/10/02 08:04
  • by jojo1973