m()

Here’s how to use m() function.

A.m ()

Description:

Get members at specified positions.

Syntax:

A.m(i)	n is the lengh of sequence A, -n£i£n and i is not equal to 0; 1<=i<=n indicates getting the ith member; -n<=i<=-1 indicates getting the ith member from the bottom.
A.m(P)	P is a non-zero n-integer sequence.

Note:

A is a sequence whose length is n, from which you get members at specified positions. The function is generally used to get members of a sequence from backwards to forwards.

Parameter:

A	A sequence expression.
i	An integer.
P	A non-zero n-integer sequence.

Option:

@r	Turn back if the specified position exceeds the boundary of A, that is, if the integer i that exceeds the limit of sequence A can be fully divided by n, i is equal to n; otherwise, i is equal to the remainder of i divided by n.
@0	The member represented by a sequence number that exceeds the boundary of A will be excluded from the result.

Return value:

A value or a sequence composed of the members at the specified positions in sequence A

Example:

	A
1	[a,b,c,d,e,f,g,h,i,j]
2	=A1.m(2)	b
3	=A1.m(-2)	i
4	=A1.m([2,3])	[b,c]
5	=A1.m([-2,-3])	[i,h]
6	=A1.m@0([5,12])	[e]
7	=A1.m@r([5,12])	[e,b]

Related function:

A.p()

A.m(a:b,c,d:e)

Description:

Get members of a sequence at specified positions to form a new sequence.

Syntax:

A.m(a:b,c,d:e)

Note:

A is a sequence whose length is n, from which you get members at specified positions to form a new sequence, with the condition -n£a£n & a!=0. If 1£a£n, it is the a^th member of sequence A when counted from left to right; if -n£ a £-1, it is the a^th member of sequence A when counted from right to left. The rules also apply to b, c, d, and e. So, the function is often used to get members of a sequence backwards. The members a and d represent must be respectively on the left side of the members b and e designate. When the parameter on the left side of the colon is omitted, the default value is 1; when the parameter on the right side of the colon is omitted, the default value is -1.

Parameter:

A	A sequence.
a/d	An integer; 1 by default.
b/e	An integer; -1 by default.
c	An integer.

Return value:

Sequence

Example:

	A
1	=to(1,100).m(1:3,9,97:)	[1,2,3,9,97,98,99,100]
2	=to(1,100).m(:5,-1,66:-32)	[1,2,3,4,5,100,66,67,68,69]