RaqForum 25 No.
2 Reply  •  312 View  • 
     ...

Generate the Text Histogram

 
sample program(31)

Problem

This problem aims to simulate the histogram via text.

Below is the Employee table, in which the DEPTNO field indicates the department the employee belongs to.

EMPNO ENAME DEPTNO
7934 Miller 10
7782 Clark 10
7839 King 10
7902 Ford 20
7788 Scott 20
7876 Adams 20
7566 Jones 20
7369 Smith 20
7900 James 30
7844 Turner 30
7654 Martin 30
7521 Ward 30
7499 Allen 30
7698 Blake 30

Now, we use text histogram to indicate the number of employees of each department, with one “*” representing one employee, and the result set illustrated by the horizontal histogram should be like this:

DEPTNO CNT
10 ***
20 *****
30 ******

The result set illustrated in the vertical histogram should be like this:

D10 D20 D30
*
* *
* *
* * *
* * *
* * *

Please develop the program to generate the result set.

Tip

1. Horizontal histogram: First, create a table sequence with DEPTNO and CNT fields. Group DEPTNO table by department . Loop through the grouped data and insert every department and *s that represent employees in the current department.

2. Vertical histogram: First, create a table sequence with the field names being dynamically retrieved departments, then count the employees of each department to get the maximum number, and insert the maximum number of blank records to the table sequence. Loop through the table sequence by column to insert the * to the table sequence.

Code

A B
1 =file("C:\\txt\\DEPTNO.txt").import@t() Load the department table
2 /Horizontal histogram
3 =create(DEPTNO,CNT) Construct the result sequence
4 =A1.group(DEPTNO) Group by DEPTNO
5 for A4
6 =A3.insert(0,A5.DEPTNO,fill("*",A5.count())) Insert records to the sequence. The first field is DEPTNO, and the second field is the * repeated for the number of employees
7 /Vertical histogram
8 =create(${A3.(DEPTNO).concat(",")}) Result sequence; field name is the dynamically retrieved DEPTNO
9 =A4.(~.count()) Count the departmental employee numbers
10 =A9.max() Count the employee numbers of the largest department
11 >A8.insert(A10) Insert the blank record according to the maximum department numbers
12 for A9
13 >A8.to(-A12).field(#A12,"*") Fill in the * column by column

Result

Horizontal histogram returned by A3

imagepng

Vertical histogram returned by A8

imagepng

sample program(31)
 
 •  312 View  •