//
//Merge command
//
//This command is used to marge current file and appoined file by keys;
//
//(Caution)
//By the merge command, appoint only a file to merge into current file

//Syntax
merge [filename]@[prjname] by [keys];

//Example 1
hand id name/
1 yosida
2 imaoka
3 nakai
4 zuzuki
6 mizuno
7 hayasi
8 imai
;

put class_names;

hand score id/ 
81	1
62	2
52	6
75	4
91	5
36	3
;

//Execute merge score by id with tempolary file 'class_names'.
merge class_names by id;



? or _ are lacked value by merge


//Plot scare by name;
plot bar score by name;