array calculation in ABAP

[Former Member]

hi gurus,

I have to use array for some calculations. I begin new project and have to calculate distance with using array. I searched forums but I found nothing. please help me?

thanks,

[former_member69765]

In ABAP we do not have concepts such as Arrays in C++ or JAVA.

We have a similar thing called Internal tables.

Internal tables are noting but a 2 dimensional arrays. You can imagine them like a table filled with values.

Try to get you job done using internal tables.

[Former Member]

In ABAP the closest concept to an "array" is an "internal table".

http://help.sap.com/saphelp_nw04/helpdata/en/d3/2e974d35c511d1829f0000e829fbfe/frameset.htm

and there are field-symbols which are same as pointers in C.

Edited by: Craig Cmehil on Jul 3, 2008 3:30 PM

[Former Member]

thanks all.

I want to explain that I want.

I want go from A to B.

intervals: 1) A-B = 600

2) A-C=50 C-F=150 F-G= 200 G-B=50

3) A-D=100 D-H=200 H-G=50 G-B=50.

we have to choose 3. but how I find this direction and min. interval? please help me.

note: sorry for my english.

[Former Member]

Hello

data: begin of itab occurs 0,
    index rype i,
    field1 type i,
    field2 type i,
    field3 type i,
    field4 type i,
end of itab.  
data: sum1 type i,
      sum2 type i,
      ind type i.

clear itab.
itab-index = itab-index + 1.
itab-field1 = 600. itab-field2 = 0. itab-field3 = 0. itab-field4 = 0.
append itab.
itab-index = itab-index + 1.
itab-field1 = 50. itab-field2 = 150. itab-field3 = 200. itab-field4 = 50.
append itab.
itab-index = itab-index + 1.
itab-field1 = 100. itab-field2 = 200. itab-field3 = 50. itab-field4 = 50.
append itab.
read table itab index 1.
if sy-subrc = 0.
  sum1 = itab-field1 + itab-field2 + itab-field3 + itab-field4.
  ind = itab-index.
endif.
loop at itab
  clear: sum2.
  sum2 = itab-field1 + itab-field2 + itab-field3 + itab-field4.
  if sum2 < sum1.
    sum1 = sum2.
    ind = itab-index.
  endif.
endloop.
read table itab with key index = ind.
if sy-subrc = 0.
  write: 'Your direction is', itab-index, 'min. interval = ', sum1.
endif.

[Former Member]

hi Maroz,

I do not mean like that. Firstly I have to find direction firstly. I dont know which I use that directions. my table fields like:

begin, end, interval. (for example: begin = 'A'. end = 'B'. interval = '600'.)

from my example, how can find 2. direction or 3. direction. (means from A to D, from D to H, H to G and from G to B. may be I go wrong direction like from H to F.) that is I have to find direction from A to B with min interval.

I think, I have to calculate all records in my table and find min intervals. but I dont know how I do it.

note: please forgive me for my english.

[Former Member]

Hello

Are you have example of the code on other language (C/C++/C# etc) ?

[Former Member]

#include <stdio.h>

int main()
{

int m,n,mat[100][100],i,j,l;
int a,b,top,max=50000;

char k1='c'; 
	
printf("total country = ");
scanf(" %d", &n);

printf(" total direction = ");  // total road: A-C is a road B-G is another road
scanf(" %d", &m);


	for(i=1;i<=n;i++){

		for(j=1;j<=n;j++){

			mat<i>[j]=max;
		}	
	}

for(i=1;i<=n;i++)
{
    mat<i><i>=0;
}

for(i=1;i<=m;i++)
{
printf("enter first country ");
scanf("%d", &a);

printf("enter second country",i);
scanf(" %d", &b);

printf("intervals of countries");
scanf("%d", &mat[a]<b>);

mat<b>[a]=mat[a]<b>;
}

for(l=1;l<=n;l++)
{

	for(i=1;i<=n;i++)
{
	       

	                	for(j=1;j<=n;j++)
{

							
		                          top=mat<i>[l] + mat[l][j];
			  
			                           if(top < mat<i>[j]){
			             
			                              mat<i>[j]=top;
			}
												
		}	
	
	}


}
while(k1 != 'q')
{
printf(" enter to find interval of 2 countries = ");

scanf(" %d", &a);
scanf(" %d", &b);

printf(" min interval = %d \n",mat[a]<b>);

printf(" q for quit any key for continue = ");
scanf(" %c", &k1);
}




}

intervals: 1) A-B = 600

2) A-C=50 C-F=150 F-G= 200 G-B=50 (that is A-B = 450)

3) A-D=100 D-H=200 H-G=50 G-B=50. (that is A-B = 400)

example records in my table

A | B | C | D | F | G | H

A | 0 | 600 | 50 | 100 | - | - | -

B |600 | 0 | - | - | - | 50| -

C | 50 | - | 0 | - | 150| - | -

D |100 | - | - | 0 | - | - |200

F |- | - |150| - | 0 |200|-

G |- | 50 |- | - | 200| 0 |50

H |- |- | - | 200 | - | 50| 0

after program run

A | B | C | D | F | G | H

A | 0 | 400 | 50 | 100 | 200 |350 | 300

B |400 | 0 | 400| 300 | 250 | 50 | 100

C | 50 | 400 | 0 | 150 | 150 | 350 | 400

D |100 |300 | 150 | 0 | 300 | 250 |200

F |200 |250 |150 |300 | 0 | 200 |250

G |350 | 50 |350 | 250 | 200 | 0 |50

H |300 |100 | 400 | 200 | 250 | 50 | 0

I dont update my table. I just want find direction and min interval to go from A to B.

I think not hard for gurus.

thank all for help.

[matt]

Define your "array" like this:

TYPES: BEGIN OF mat_ty,
         dim1 TYPE i,
         dim2 TYPE i,
         valu TYPE i,
       END OF mat_ty.

DATA: t_mat  TYPE HASHED TABLE OF mat_ty WITH UNIQUE KEY dim1 dim2,
      ls_mat TYPE mat_ty.

FIELD-SYMBOLS: <ls_mat> TYPE mat_ty.

Now, the array has to be initialised before you can use it. For each "point" in the "array" x,y, where x and y are integers, you need to do something like:

ls_mat-dim1 = x.
ls_mat-dim2 = y.
ls_mat-valu = 50000. " for example
INSERT ls_mat INTO TABLE lt_mat.

Once you've initialised all the points, you can access a "point" x,y in the "array" using READ.

READ TABLE ls_mat WITH TABLE KEY dim1 = x dim2 = y ASSIGNING <ls_mat>.
IF <ls_mat> IS ASSIGNED... " If it isn't assigned then the point wasn't initialised
  <ls_mat>-valu = new_value. " This line changes the value of the "point" you've just read from the "array". 
,,,

With the code you've already got, that should be sufficient to get your solution. Here's a beginning.

DATA: i TYPE i,
      j TYPE i,
      l TYPE i,
      a TYPE i,
      b TYPE i,
      top TYPE i.

CONSTANTS: max TYPE i VALUE 50000.

FIELD-SYMBOLS: <ls_mat> TYPE mat_ty.

TYPES: BEGIN OF mat_ty,
         dim1 TYPE i,
         dim2 TYPE i,
         valu TYPE i,
       END OF mat_ty.

DATA: t_mat  TYPE HASHED TABLE OF mat_ty WITH UNIQUE KEY dim1 dim2,
      ls_mat TYPE mat_ty.

PARAMETERS: n TYPE i, " Total country
            m TYPE i. " Total direction.

i = 1.
DO.
  IF i GT n.
    EXIT.
  ENDIF.
  DO.
    j = 1.
    IF j GT n.
      EXIT.
    ENDIF.
    ls_mat-dim1 = i.
    ls_mat-dim2 = j.
    ls_mat-valu = max.
    INSERT ls_mat INTO TABLE lt_mat.
    ADD 1 TO j.
  ENDDO.
  ADD 1 TO i.
ENDDO.

i=1.
DO.
  IF i GT n.
    EXIT.
  ENDIF.
  READ TABLE lt_mat WITH TABLE KEY dim1 = i dim2 = i ASSIGNING <ls_mat>.
  CLEAR <ls_mat>-valu.
ENDDO.

Regards

matt

[Former Member]

thanks matt,

I did like you. of course changed something but generally problem solved with your method. again thanks. another thanks to jan.

[Former Member]

hi,

Internal Table is the concept which is similar to Arrays in other programming languages.

begin of fs_data,
   int type i,
end of fs_data.

data t_data like
standard table of fs_data.

This will create a single dimensional Array like structure. Fill data in it and perform Operations.

Hope this will help.

Sumit Agarwal

Edited by: Craig Cmehil on Jul 3, 2008 3:30 PM

[Former Member]

thanks Matt,

your code for helpful for me. I wrote like that, but still I dont know direction that I use. and there is no calculation for min interval. if I am wrong you just find interval of just 2 countries. I want to say may be no any road from A to B to directly ( mean, there is no record in my table). you have to go via neighbor of countries. ( ex: Via D,H and G) I have to calculate interval of neigbor's interval of these two countries.

note: I dont know, but may be there is a FM for this problem. if it is, may result my problem.

[matt]

I've answered your question (I think) about how to emulate arrays, so that you should be able to just translate your C program into ABAP quite easily. Does the C program work? I've only made a start on translating from your program into ABAP - you need to do the rest yourself.

I don't really understand what the program is trying to achieve, so I can't help you on that bit, I'm afraid.

[JanStallkamp]

Hi.

I think Matthew has given a lot of input about how to solve your task in ABAP. I would suggest that you try to understand the algorithm used in the C-code beforehand. The interesting part is in the nested loops... But I would say that the used algorithm to compute the shortest distance might not be the best available. Do you really have a business requirement for such a program? If yes: how large might the number of citys/countrys get, what is the typical number? Do you really need distances for all pairs or do you just need a few? Depending on your scenario some other algorithms might be better.

Best regards,

Jan Stallkamp