PROGRAM BT1_14
	PARAMETER (NMAX=100,MMAX=8)
	REAL XX(NMAX,0:MMAX),X(NMAX),NFR(NMAX),FR(NMAX),XC(NMAX),F(NMAX)
	REAL XC1(NMAX,MMAX),FR1(NMAX,MMAX),F1(NMAX,MMAX),NFR1(NMAX,MMAX)
	INTEGER N,M,I,N1
	REAL XMAX,XMIN,STEP
	CHARACTER*2 DIREC(MMAX)
!  MO TA HUONG GIO
	DATA DIREC /' N','NE',' E','SE',' S','SW',' W','NW'/
! DOC SO LIEU
	OPEN(1,FILE='C:\MASTER\G_TR\BAITAP~1\NEW\BANG4.TXT')
	READ(1,*)
	READ(1,*)
	READ(1,*)N, M
      READ(1,*)((XX(I,J),J=0,M), I=1,N)
! TIM MAX, MIN CHO TAT CA CAC HUONG
	XMAX=XX(1,1)
	XMIN=XX(1,1)
	DO I=1,N
	DO J=1,M
	   IF (XX(I,J).LT.XMIN) XMIN=XX(I,J)
	   IF (XX(I,J).GT.XMAX) XMAX=XX(I,J)
	ENDDO
	ENDDO
! GAN TOC DO NHO NHAT = 0 VA KHOANG TOC DO (STEP)
	XMIN=0.0
	STEP=2.0
	
	DO 100 J=1,M
! BAT DAU CHU TRINH TINH CHO TUNG HUONG
	DO I=1,N
	   X(I)=XX(I,J)
	ENDDO
!
	CALL FREQ_V(X,N,XC,FR,F,NFR,N1,XMAX,XMIN,STEP)
	DO I=1,N1
	   XC1(I,J)=XC(I)
	   FR1(I,J)=FR(I)
	   F1(I,J)=F(I)
	   NFR1(I,J)=NFR(I)
	ENDDO
 100  CONTINUE
	DO 101 J=1,M	
	WRITE(*,'(" HAM P.BO (FR) VA M.DO (F) - HUONG ",A2)')DIREC(J)
	WRITE(*,*)' I ','   XC  ','    FR  ','    F  ','   NFR '

	DO I=1,N1
	WRITE(*,'(I3,F7.1,3F8.4)') I,XC1(I,J),FR1(I,J),F1(I,J),NFR1(I,J)
	ENDDO
	PAUSE
 101	CONTINUE
	END


	SUBROUTINE FREQ_V(X,N,XC,FR,F,NFR,M,XMAX,XMIN,STEP)
C
C  CHUONG TRINH NAY TINH TAN SO (NFR) VA TAN SUAT (FR)
C  CUA MANG X DO DAI N.
C INPUT:  + MANG X CHUA GIA TRI QUAN TRAC CUA BIEN NGAU NHIEN
C         + N LA DUNG LUONG MAU
C         + XMAX,XMIN,STEP: MAX, MIN VA CU LY NHOM
C                    
C OUTPUT: + M LA SO KHOANG CHIA
C         + XC MANG DO DAI M CHUA TRI SO TRUNG GIAN CUA CAC KHOANG
C         + NFR MANG DO DAI M CHUA TAN SO CAC NHOM
C         + FR MANG DO DAI M CHUA TAN SUAT TICH LUY CAC NHOM (HAM PHAN BO)
C         + F MANG DO DAI M CHUA MAT DO XAC SUAT CAC NHOM
C
      REAL X(1),NFR(1),FR(1),XC(1),F(1)
	INTEGER N,INTERVAL,M
	REAL XMIN,XMAX,STEP
	M=INT((XMAX-XMIN)/STEP)+1
C  TINH XC
      XC(1)=XMIN+STEP/2.0
	DO J=2,M
	   XC(J)=XC(J-1)+STEP
	ENDDO
C  TINH TAN SO CAC KHOANG VA HAM PHAN BO, HAM MAT DO
      STEP=STEP/2.0
	DO J=1,M
	   NFR(J)=0.0
	   DO I=1,N
	      IF ((X(I).GE.XC(J)-STEP).AND.(X(I).LT.XC(J)+STEP)) THEN
	         NFR(J)=NFR(J) + 1
	      ENDIF
	   ENDDO
	   FR(J)=NFR(J)/REAL(N)
	ENDDO
	STEP=STEP*2.0
	DO J=M,1,-1
	   F(J)=FR(J)/STEP
	   TEMP=0.0
	   DO K=1,J
	      TEMP=TEMP+FR(K)
	   ENDDO
	   FR(J)=TEMP
	ENDDO
	RETURN
	END