top()

Read(312) Label: get, smallest members, sequence,

Here’s how to use top() function.

A.top()

Description:

Get the n smallest members from a sequence.

Syntax:

A.top(n,x)  Calculates expression x over each member of the sequence and return a sequence consisting of the first n smallest values of x

A.top(n;x,...)   Calculates expression x over each member of the sequence and return a sequence consisting of the first n smallest members

A.top(n,y,x)  Loop members of sequence A to compute expression x, then loop the results to compute expression y, and finally return a sequene of x’s results that correspond to the top n smallest values of y.

Note:

The function evaluates expression x with each member of the sequence A and returns the n smallest members. n must not be omitted. The omission of x is equivalent to ~.

Parameters:

A

A sequence

n

An integer

y

An expression

x

An expression

Options:

@1

Return a single value if n is ±1; and null if n is 0

@2

Calculate the concatenation of all sequence-type members in sequence A and get the first n smallest members from the new sequence

Return value:

Sequence

Example:

 

A

 

1

[a,c,e,g,f,d,b]

 

2

=A1.top(3,~)

3

=A1.top(3)

Same as A2, when x is omitted

4

=demo.query("select * from EMPLOYEE")

 

5

=A4.top(10,SALARY)

 

Get the salaries of 10 employees who are the lowest paid

6

=A4.top(10;SALARY)

Get the records of 10 employees who are the lowest paid

7

[21,3,12,5]

 

8

=A6.top(3,~%10,~+6)

[11,27,18]

9

=A7.top(-1)

10

=A7.top@1(-1)

11

=A4.top(10;SALARY,EID)

Get top 10 employee records where SALARY is the lowest and EID is the smallest

12

[12,5,-6]

 

13

[36,1,15,9,85]

 

14

=[A12,A13].top@2(2)

Concatenate A12 and A13 and get the first two smallest values

IMG_256

Related functions:

A.pos()

A.sort()

A.pos(x)

A.psort()

A.ptop()