m()

Read(208) Label: m,

Here’s how to use m() function.

A .m()

Description:

Get members at specified positions.

Syntax:

A.m(i)

-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 reversely from a sequence.

Parameters:

A

A sequence expression

i

An integer

P

A non-zero n-integer sequence

Options:

@r

Turn back if the specified position exceeds the boundary of A, that is, to set i=if(i%n==0,n,i%n), where n is the length of A.

@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 functions:

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 ath member of sequence A when counted from left to right; if -n£ a £-1, it is the ath member of sequence A when counted from right to left. The rules also apply to b, c, d, and e. So the function is ofent used to get members reversely from a sequence. 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.

Parameters:

A

A sequence

a

An integer; 1 by default

b

An integer; -1 by default

c

An integer

d

An integer; 1 by default

e

An integer; -1 by default

Return value:

A 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]