manual:chapter6:lists:cmd

Synopsis

Assemble a list from results of sequential procedure

Stack Diagram

Input Stack						Output Stack
P_exec	N_index	Num_start	Num_end	Num_incr	→	L_results
A_exec	N_index	Num_start	Num_end	Num_incr	→	L_results
N_exec	N_index	Num_start	Num_end	Num_incr	→	L_results
Level 5	Level 4	Level 3	Level 2	Level 1	→	Level 1

Legend

Legend	Object type
O	Any object
I	Integer number
R	Real number
#	Binary number
Num	Scalar (Integer, Real or Binary number)
Z	Complex number
U	Unit
∡	Angle
A	Symbolic expression
C	Symbolic constant
V	Vector
M	Matrix
S	String
1/0	Any expression evaluating to True or False
G	Grob
F	Font
D	Binary data container
T	Tag object
L	List
cL	Case list
N	Variable name / Identifier
Dir	Directory
pDir	Packed Directory
P	Program
Lib	Library

Keyword type	Command
Parallel list processing capabilities	Group 7	Multiple argument, one result commands
Affected by flags	None

Description

The SEQ command returns a list of results generated by repeatedly EVALuating a program, a symbolic object or an identifier using N_index over the range Num_start to Num_end, in increments of Num_incr.

The action of SEQ for arbitrary inputs can be predicted exactly from this equivalent program:

Numstart Numend FOR 'Nindex'
  Pexec EVAL
Numincr STEP
n → LIST

where n is the number of new objects left on the stack by the FOR … STEP loop. Notice that N_index becomes a local variable regardless of its original type.

Compatibility

SEQ is not fully equivalent to its userRPL counterpart.

In particular:

the program launched by SEQ operates in a protected stack environment: no elements present on the stack before SEQ is launched can be reached or altered.

Usage

Input

5:                                 'n^2'
4:                                   'n'
3:                                     1
2:                                     9
1:                                     2
…………………………………………………………………………………………………………
SEQ

Output

4:                                      
3:                                      
2:                                      
1:            { '1' '9' '25' '49' '81' }
…………………………………………………………………………………………………………

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