Two dimensional arrays?

**ralfmayr** · - 15th March 2010, 13:54

Is there a possibility to define 2 dimensional arrays in PBP, e.g. data(i,k) ?
Regards,
Ralf

**Darrel Taylor** · - 15th March 2010, 19:53

Not directly, but you can do the same thing programmatically.

Say it's 8x8 ...

Code:

MyArray  VAR BYTE[64]

A = MyArray(i*8+k)

Indexes are 0-7.

**rsocor01** · - 16th March 2010, 20:08

Hi,

Well, I was thinking about starting a thread in the "PBP Wish List" about two dimensional arrays in PBP, but Darrel's approach would do just the same. Is is a clever way of mapping a two-dimensional space into a one-dimensional one. This is probably the way how other computer languages internally handle a multi-dimensional array.

Robert

**Darrel Taylor** · - 16th March 2010, 22:58

Code:

; -- Working with 2D arrays ---

<font color="#000000"><b>Width      </b><font color="#008000"><b>CON </b></font><font color="#800000"><b>8                      </b></font><font color="#0000FF"><b><i>; Number of bytes in a Row
</i></b></font><b>Length     </b><font color="#008000"><b>CON </b></font><font color="#800000"><b>10                     </b></font><font color="#0000FF"><b><i>; Number of Rows in the array
;---------------------------------------------------------------------------
</i></b></font><b>ArraySize  </b><font color="#008000"><b>CON </b></font><b>Width </b>* <b>Length         </b><font color="#0000FF"><b><i>; Total size of the array
</i></b></font><b>MyArray    </b><font color="#008000"><b>VAR BYTE</b></font>[<b>ArraySize</b>]        <font color="#0000FF"><b><i>; The Array

</i></b></font><b>Idx        </b><font color="#008000"><b>VAR BYTE                   </b></font><font color="#0000FF"><b><i>; Index, points to 1D array locations
</i></b></font><b>Xidx       </b><font color="#008000"><b>VAR BYTE                   </b></font><font color="#0000FF"><b><i>; 2D column Index
</i></b></font><b>Yidx       </b><font color="#008000"><b>VAR BYTE                   </b></font><font color="#0000FF"><b><i>; 2D row Index
</i></b></font><b>ArrayData  </b><font color="#008000"><b>VAR BYTE                   </b></font><font color="#0000FF"><b><i>; holding register for array data

;----[Get a value from the 2D array]----------------------------------------
</i></b></font><b>Get2D</b>:
    <b>Idx</b>=(<b>Yidx</b>*<b>Width</b>+<b>Xidx</b>) <font color="#008000"><b>MIN </b></font>(<b>ArraySize</b>-<font color="#800000"><b>1</b></font>) <font color="#0000FF"><b><i>; find Index, limit to ArraySize 
    </i></b></font><b>ArrayData </b>= <b>MyArray</b>(<b>Idx</b>)                <font color="#0000FF"><b><i>; retrieve value from the array
</i></b></font><font color="#008000"><b>RETURN

</b></font><font color="#0000FF"><b><i>;----[Put a value in the 2D array]------------------------------------------
</i></b></font><b>Put2D</b>:
    <b>Idx</b>=(<b>Yidx</b>*<b>Width</b>+<b>Xidx</b>) <font color="#008000"><b>MIN </b></font>(<b>ArraySize</b>-<font color="#800000"><b>1</b></font>) <font color="#0000FF"><b><i>; find Index, limit to ArraySize 
    </i></b></font><b>MyArray</b>(<b>Idx</b>) = <b>ArrayData                </b><font color="#0000FF"><b><i>; store the value in the array
</i></b></font><font color="#008000"><b>RETURN

</b></font><font color="#0000FF"><b><i>;----[Set entire array to 0's]----------------------------------------------
</i></b></font><b>Clear2D</b>:
    <font color="#008000"><b>FOR </b></font><b>Idx </b>= <font color="#800000"><b>0 </b></font><font color="#008000"><b>TO </b></font><b>ArraySize</b>-<font color="#800000"><b>1
        </b></font><b>MyArray</b>(<b>Idx</b>) = <font color="#800000"><b>0
    </b></font><font color="#008000"><b>NEXT </b></font><b>Idx
</b><font color="#008000"><b>RETURN

</b></font><font color="#0000FF"><b><i>;----[Turn the Subroutines into Functions]----------------------------------
</i></b></font><font color="#008000"><b>ASM
</b></font><font color="#000080">#Get2D macro X, Y
    MOVE?BB   X, _Xidx                      </font><font color="#0000FF"><b><i>; copy users X value to Xidx
    </i></b></font><font color="#000080">MOVE?BB   Y, _Yidx                      </font><font color="#0000FF"><b><i>; copy users Y value to Yidx
    </i></b></font><font color="#000080">L?CALL    _Get2D                        </font><font color="#0000FF"><b><i>; call the Get subroutine
  </i></b></font><font color="#000080">endm                                      </font><font color="#0000FF"><b><i>; value is returned in ArrayData
</i></b></font><font color="#000080">#define Get2D(X, Y)  #Get2D X, Y            </font><font color="#0000FF"><b><i>; allows paretheses in macro
;-----------------------
</i></b></font><font color="#000080">#Put2D macro X, Y                           </font><font color="#0000FF"><b><i>; value should be in ArrayData
    </i></b></font><font color="#000080">MOVE?BB   X, _Xidx                      </font><font color="#0000FF"><b><i>; copy users X value to Xidx
    </i></b></font><font color="#000080">MOVE?BB   Y, _Yidx                      </font><font color="#0000FF"><b><i>; copy users Y value to Yidx
    </i></b></font><font color="#000080">L?CALL    _Put2D                        </font><font color="#0000FF"><b><i>; call the Put subroutine
  </i></b></font><font color="#000080">endm
#define Put2D(X, Y)  #Put2D X, Y            </font><font color="#0000FF"><b><i>; allows paretheses in macro
;-----------------------
</i></b></font><font color="#000080">#Clear2D macro
    L?CALL    _Clear2D                      </font><font color="#0000FF"><b><i>; call the Clear subroutine
  </i></b></font><font color="#000080">endm
#define Clear2D()  #Clear2D
</font><font color="#008000"><b>ENDASM

</b></font>

Code:

<font color="#0000FF"><b><i>;____[The Main Program]_____________________________________________________

</i></b></font><b>X        </b><font color="#008000"><b>VAR BYTE </b></font><b>SYSTEM
Y        </b><font color="#008000"><b>VAR BYTE </b></font><b>SYSTEM

Main</b>:
    @ <b>Clear2D                       </b><font color="#0000FF"><b><i>; clear the array
    
    </i></b></font><font color="#008000"><b>FOR </b></font><b>Y </b>= <font color="#800000"><b>0 </b></font><font color="#008000"><b>TO </b></font><b>Length</b>-<font color="#800000"><b>1           </b></font><font color="#0000FF"><b><i>; fill the array with data
      </i></b></font><font color="#008000"><b>FOR </b></font><b>X </b>= <font color="#800000"><b>0 </b></font><font color="#008000"><b>TO </b></font><b>Width</b>-<font color="#800000"><b>1
          </b></font><b>ArrayData </b>= <b>X             </b><font color="#0000FF"><b><i>; value to put in array
          </i></b></font>@ <b>Put2D</b>(<b>X</b>,<b>Y</b>)
      <font color="#008000"><b>NEXT </b></font><b>X
    </b><font color="#008000"><b>NEXT </b></font><b>Y
    
    </b><font color="#008000"><b>FOR </b></font><b>Y </b>= <font color="#800000"><b>0 </b></font><font color="#008000"><b>TO </b></font><b>Length</b>-<font color="#800000"><b>1           </b></font><font color="#0000FF"><b><i>; Read data back and send to serial port
      </i></b></font><font color="#008000"><b>FOR </b></font><b>X </b>= <font color="#800000"><b>0 </b></font><font color="#008000"><b>TO </b></font><b>Width</b>-<font color="#800000"><b>1
          </b></font>@ <b>Get2D</b>(<b>X</b>,<b>Y</b>)
          <font color="#008000"><b>HSEROUT </b></font>[<font color="#008000"><b>HEX2 </b></font><b>ArrayData</b>,<font color="#FF0000">&quot;, &quot;</font>]
      <font color="#008000"><b>NEXT </b></font><b>X
      </b><font color="#008000"><b>HSEROUT </b></font>[<font color="#800000"><b>13</b></font>,<font color="#800000"><b>10</b></font>]
    <font color="#008000"><b>NEXT </b></font><b>Y 
    </b><font color="#008000"><b>HSEROUT </b></font>[<font color="#800000"><b>13</b></font>,<font color="#800000"><b>10</b></font>]

    <font color="#008000"><b>PAUSE </b></font><font color="#800000"><b>3000
</b></font><font color="#008000"><b>GOTO </b></font><b>Main</b>

Code:

[color=#0000FF][b][i];____[Working with 2D arrays]_____________________________________________________
Width      CON 8                      ; Number of bytes in a Row
 Length     CON 10                     ; Number of Rows in the array
 ;---------------------------------------------------------------------------
 ArraySize  CON Width * Length         ; Total size of the array
 MyArray    VAR BYTE[ArraySize]        ; The Array
 
Idx        VAR BYTE                   ; Index, points to 1D array locations
 Xidx       VAR BYTE                   ; 2D column Index
 Yidx       VAR BYTE                   ; 2D row Index
 ArrayData  VAR BYTE                   ; holding register for array data
 
;----[Get a value from the 2D array]----------------------------------------
 Get2D:
     Idx=(Yidx*Width+Xidx) MIN (ArraySize-1) ; find Index, limit to ArraySize 
    ArrayData = MyArray(Idx)                ; retrieve value from the array
 RETURN
 
;----[Put a value in the 2D array]------------------------------------------
 Put2D:
     Idx=(Yidx*Width+Xidx) MIN (ArraySize-1) ; find Index, limit to ArraySize 
    MyArray(Idx)=ArrayData                ; store the value in the array
 RETURN
 
;----[Set entire array to 0's]----------------------------------------------
 Clear2D:
     FOR Idx = 0 TO ArraySize-1
         MyArray(Idx)=0
     NEXT Idx
 RETURN
 
;----[Turn the Subroutines into Functions]----------------------------------
 ASM
 #Get2D macro X, Y
     MOVE?BB   X, _Xidx                      ; copy users X value to Xidx
     MOVE?BB   Y, _Yidx                      ; copy users Y value to Yidx
     L?CALL    _Get2D                        ; call the Get subroutine
   endm                                      ; value is returned in ArrayData
 #define Get2D(X, Y)  #Get2D X, Y            ; allows paretheses in macro
 ;-----------------------
 #Put2D macro X, Y                           ; value should be in ArrayData
     MOVE?BB   X, _Xidx                      ; copy users X value to Xidx
     MOVE?BB   Y, _Yidx                      ; copy users Y value to Yidx
     L?CALL    _Put2D                        ; call the Put subroutine
   endm
 #define Put2D(X, Y)  #Put2D X, Y            ; allows paretheses in macro
 ;-----------------------
 #Clear2D macro
     L?CALL    _Clear2D                      ; call the Clear subroutine
   endm
 #define Clear2D()  #Clear2D
 ENDASM

Code:

;____[The Main Program]_____________________________________________________

X        VAR BYTE SYSTEM
Y        VAR BYTE SYSTEM

Main:
    @ Clear2D                       ; clear the array
    
    FOR Y = 0 TO Length-1           ; fill the array with data
      FOR X = 0 TO Width-1
          ArrayData = X             ; value to put in array
          @ Put2D(X,Y)
      NEXT X
    NEXT Y
    
    FOR Y = 0 TO Length-1           ; Read data back and send to serial port
      FOR X = 0 TO Width-1
          @ Get2D(X,Y)
          HSEROUT [HEX2 ArrayData,&quot;, &quot;]
      NEXT X
      HSEROUT [13,10]
    NEXT Y 
    HSEROUT [13,10]

    PAUSE 3000
GOTO Main

**ralfmayr** · - 19th March 2010, 10:33

Hi Darrel,
great idea, i will test this.
BTW:
1. What is maximum size of an array (i use 18F6722)? I would need two array's
with a width of 10 bytes and a length of max 256!
2. The length of the array should be dynamically, means that after configuring
the SW via RS232, the controller will be reseted and the array length will be redefined.
But this is not possible in runtime, or? Only at compile-time !?
Regards,
Ralf

**ralfmayr** · - 19th March 2010, 13:45

Silly question, i only have 3936 bytes in a 6722....

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Two dimensional arrays?

Ok, Everyone break out their Butterfly Nets. :)

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