SUBROUTINE SHADE(BXORIG,BYORIG,BXSIZE,BYSIZE,BWCOL,
     & IBASE,RATIO,MODE)
      parameter (nbot_max = 5000, nbm= nbot_max+20)
C
      CHARACTER*3 XBTYPE, YBTYPE, BWCOL, MODE
      CHARACTER*80 TITLEX,TITLEY
      COMMON /BOTT/ XF(nbm), YF(nbm), NPBOTT, ISHADE, NPSH
      COMMON /SH/ PF(440), QF(440), UF(440), VF(440)
      COMMON /XAX/ X1,XL,XLEFT,XRIGHT,XSCALE,XINC,DX,
     &             X1PL,XLPL,NX,X1GRID,XLGRID,DIVX,XVAL(100),NXVAL
      COMMON /YAX/ Y1,YL,YUP,YDOWN,YSCALE,YINC,DY,
     &             Y1PL,YLPL,NY,Y1GRID,YLGRID,DIVY,YVAL(100),NYVAL
      COMMON /XAXC/ TITLEX, XBTYPE
      COMMON /YAXC/ TITLEY, YBTYPE

      IF(NPSH.LE.2)     RETURN
      IF(NPSH+3.GT.220)  STOP 'ERROR IN SUB SHADE'
C
      IF(YBTYPE.EQ.'LOG')     THEN
       DO 1000  I=1,NPSH
       QF(I)=10.0*ABS(ALOG(VF(I)/YDOWN)/ALOG(2.0))*YSCALE
 1000  CONTINUE
      ELSE
       DO 1200   I=1,NPSH
       QF(I)=BYORIG+BYSIZE*((VF(I)-YDOWN)/(YUP-YDOWN))
 1200  CONTINUE
      END IF
C
      IF(XBTYPE.EQ.'LOG')   THEN
       DO 2000  I=1,NPSH
       PF(I)=10.0*ABS(ALOG(UF(I)/XLEFT)/ALOG(2.0))*XSCALE
 2000  CONTINUE
      ELSE
       DO 2200   I=1,NPSH
       PF(I)=BXORIG+BXSIZE*((UF(I)-XLEFT)/(XRIGHT-XLEFT))
 2200  CONTINUE
      END IF
C
      DO 3200   I=1,NPSH
      PF(I)=(PF(I)-BXORIG)*RATIO + BXORIG
      QF(I)=(QF(I)-BYORIG)*RATIO + BYORIG
 3200 CONTINUE
C
      IF(BWCOL.EQ.'COL')   THEN
       if (ishade.gt.0) then
        CALL RFMODE( MODE )
        CALL RSURF(PF,QF,NPSH,IBASE+ISHADE,1)
       end if
      END IF
      CALL GVECT(PF(1),QF(1),0)
      DO 4000   I=1,NPSH
      CALL GVECT(PF(I),QF(I),1)
 4000 CONTINUE
      RETURN
      END