INCLUDE "H6:REALMATH.ACT"

DEFINE SIZE="10000"
DEFINE HIST_SIZE="10"
BYTE ARRAY data(SIZE)
CARD ARRAY hist(HIST_SIZE)

PROC Generate()
  INT i

  FOR i=0 TO SIZE-1
  DO
    data(i)=Rand(0)
  OD
RETURN

PROC CalcMean(INT count REAL POINTER mean)
  REAL tmp1,tmp2,r255
  INT i

  IntToReal(0,mean)
  IntToReal(255,r255)
  FOR i=0 TO count-1
  DO
    IntToReal(data(i),tmp1)
    RealDiv(tmp1,r255,tmp2)
    RealAdd(mean,tmp2,tmp1)
    RealAssign(tmp1,mean)
  OD
  IntToReal(count,tmp1)
  RealDiv(mean,tmp1,tmp2)
  RealAssign(tmp2,mean)
RETURN

PROC CalcStdDev(INT count REAL POINTER mean,sdev)
  REAL tmp1,tmp2,r255
  INT i

  IntToReal(0,sdev)
  IntToReal(255,r255)
  FOR i=0 TO count-1
  DO
    IntToReal(data(i),tmp1)
    RealDiv(tmp1,r255,tmp2)
    RealSub(tmp2,mean,tmp1)
    RealMult(tmp1,tmp1,tmp2)
    RealAdd(sdev,tmp2,tmp1)
    RealAssign(tmp1,sdev)
  OD
  IntToReal(count,tmp1)
  RealDiv(sdev,tmp1,tmp2)
  Sqrt(tmp2,sdev)
RETURN

PROC ClearHistogram()
  BYTE i

  FOR i=0 TO HIST_SIZE-1
  DO
    hist(i)=0
  OD
RETURN

PROC CalcHistogram(INT count)
  INT i,index

  ClearHistogram()
  FOR i=0 TO count-1
  DO
    index=data(i)*10/256
    hist(index)==+1
  OD
RETURN

PROC PrintHistogram()
  BYTE i,j,n
  INT max
  REAL tmp1,tmp2,rmax,rlen

  max=0
  FOR i=0 TO HIST_SIZE-1
  DO
    IF hist(i)>max THEN
      max=hist(i)
    FI
  OD
  IntToReal(max,rmax)
  IntToReal(25,rlen)

  FOR i=0 TO HIST_SIZE-1
  DO
    PrintF("0.%Bx: ",i)
    IntToReal(hist(i),tmp1)
    RealMult(tmp1,rlen,tmp2)
    RealDiv(tmp2,rmax,tmp1)
    n=RealToInt(tmp1)
    FOR j=0 TO n
    DO
      Put('*)
    OD
    PrintF(" %U",hist(i))
    IF i<HIST_SIZE-1 THEN
      PutE()
    FI
  OD
RETURN

PROC Test(INT count)
  REAL mean,sdev

  PrintI(count)
  CalcMean(count,mean)
  Print(": m=") PrintR(mean)
  CalcStdDev(count,mean,sdev)
  Print(" sd=") PrintRE(sdev)
  CalcHistogram(count)
  PrintHistogram()
RETURN

PROC Main()
  Put(125) PutE() ;clear screen
  MathInit()
  Generate()
  Test(100)
  PutE() PutE()
  Test(10000)
RETURN