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- /* Kohonen Feature Maps in E, implemented with integers
-
- Kohonen feature maps are special types of neural nets, and
- this implementation shows graphically how they organise themselves
- after a while. Apologies for the primitive gfx display.
-
- */
-
- CONST ONE=1024*16, KSHIFT=14, KSIZE=7, MAXTIME=500, DELAY=0
- CONST KSTEP=ONE/KSIZE, KNODES=KSIZE+1, ARSIZE=KSIZE*KSIZE
- CONST XRED=64, YRED=128, XOFF=10, YOFF=20
-
- MODULE 'intuition/intuition', 'tools/exceptions'
-
- PROC main() HANDLE
- DEF map,t,input,x,y,w=NIL
- IF w:=OpenW(20,11,400,200,$200,$F,'Kohonen Feature Map Simulation',0,1,0)
- map:=kohonen_init(KSIZE,KSIZE,2)
- FOR t:=0 TO MAXTIME-1
- input:=[Rnd(KNODES)*KSTEP,Rnd(KNODES)*KSTEP]
- x,y:=kohonen_BMU(map,input)
- kohonen_plot(map,w,x,y)
- kohonen_learn(map,x,y,MAXTIME-t*(ONE/MAXTIME),input)
- ENDFOR
- ELSE
- Raise("WIN")
- ENDIF
- RefreshWindowFrame(w)
- WaitIMessage(w)
- EXCEPT DO
- report_exception()
- IF w THEN CloseW(w)
- ENDPROC
-
- PROC kohonen_plot(map,wnd:PTR TO window,bx,by)
- DEF x,y,n:PTR TO LONG,cx,cy,i,ii,
- sx[ARSIZE]:ARRAY OF LONG,sy[ARSIZE]:ARRAY OF LONG
- SetRast(wnd.rport,1)
- FOR x:=0 TO KSIZE-1
- FOR y:=0 TO KSIZE-1
- n:=kohonen_node(map,x,y); i:=x*KSIZE+y; ii:=x-1*KSIZE+y
- sx[i]:=cx:=s(n[0]/XRED+XOFF); sy[i]:=cy:=s(n[1]/YRED+YOFF)
- IF x>0 THEN Line(sx[ii],sy[ii],cx,cy,2)
- IF y>0 THEN Line(sx[i-1],sy[i-1],cx,cy,2)
- ENDFOR
- ENDFOR
- n:=kohonen_node(map,bx,by)
- Plot(s(n[0]/XRED+XOFF),s(n[1]/YRED+YOFF),2)
- Delay(DELAY)
- ENDPROC
-
- PROC s(c) IS IF c<0 THEN 0 ELSE IF c>1000 THEN 1000 ELSE c
-
- PROC kohonen_BMU(map,i:PTR TO LONG)
- DEF x,y,act,bestx,besty,bestact=$FFFFFFF,n:PTR TO LONG,len,a
- len:=ListLen(i)-1
- FOR x:=0 TO KSIZE-1
- FOR y:=0 TO KSIZE-1
- n:=kohonen_node(map,x,y)
- act:=0
- FOR a:=0 TO len DO act:=Abs(n[a]-i[a])+act
- IF act<bestact; bestx:=x; besty:=y; bestact:=act; ENDIF
- ENDFOR
- ENDFOR
- ENDPROC bestx,besty
-
- PROC kohonen_learn(m,bx,by,t,i:PTR TO LONG)
- DEF x,y,n:PTR TO LONG,d,a,len,bell:PTR TO LONG
- bell:=[50,49,47,40,25,13,10,8,6,5,4,3,2,1,1,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0]
- len:=ListLen(i)-1
- FOR x:=0 TO KSIZE-1
- FOR y:=0 TO KSIZE-1
- n:=kohonen_node(m,x,y)
- d:=t*bell[Abs(bx-x)+Abs(by-y)]/50 -> cityblock
- IF d>0
- FOR a:=0 TO len DO n[a]:=n[a]+Shr(i[a]-n[a]*d,KSHIFT)
- ENDIF
- ENDFOR
- ENDFOR
- ENDPROC
-
- PROC kohonen_node(map:PTR TO LONG,x,y)
- DEF r:PTR TO LONG
- r:=map[x]
- ENDPROC r[y]
-
- PROC kohonen_init(numx,numy,numw)
- DEF m:PTR TO LONG,r:PTR TO LONG,w:PTR TO LONG,a,b,c
- NEW m[numx]
- FOR a:=0 TO numx-1
- m[a]:=NEW r[numy]
- FOR b:=0 TO numy-1
- r[b]:=NEW w[numw]
- FOR c:=0 TO numw-1 DO w[c]:=ONE/2
- ENDFOR
- ENDFOR
- ENDPROC m
-