70 lines
1.6 KiB
Plaintext
70 lines
1.6 KiB
Plaintext
' FB 1.05.0 Win64
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Randomize
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Sub basicStats(sampleSize As Integer)
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If sampleSize < 1 Then Return
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Dim r(1 To sampleSize) As Double
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Dim h(0 To 9) As Integer '' all zero by default
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Dim sum As Double = 0.0
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Dim hSum As Integer = 0
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' Generate 'sampleSize' random numbers in the interval [0, 1)
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' calculate their sum
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' and in which box they will fall when drawing the histogram
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For i As Integer = 1 To sampleSize
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r(i) = Rnd
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sum += r(i)
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h(Int(r(i) * 10)) += 1
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Next
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For i As Integer = 0 To 9 : hSum += h(i) : Next
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' adjust one of the h() values if necessary to ensure hSum = sampleSize
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Dim adj As Integer = sampleSize - hSum
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If adj <> 0 Then
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For i As Integer = 0 To 9
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h(i) += adj
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If h(i) >= 0 Then Exit For
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h(i) -= adj
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Next
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End If
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Dim mean As Double = sum / sampleSize
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Dim sd As Double
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sum = 0.0
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' Now calculate their standard deviation
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For i As Integer = 1 To sampleSize
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sum += (r(i) - mean) ^ 2.0
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Next
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sd = Sqr(sum/sampleSize)
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' Draw a histogram of the data with interval 0.1
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Dim numStars As Integer
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' If sample size > 500 then normalize histogram to 500
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Dim scale As Double = 1.0
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If sampleSize > 500 Then scale = 500.0 / sampleSize
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Print "Sample size "; sampleSize
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Print
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Print Using " Mean #.######"; mean;
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Print Using " SD #.######"; sd
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Print
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For i As Integer = 0 To 9
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Print Using " #.## : "; i/10.0;
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Print Using "##### " ; h(i);
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numStars = Int(h(i) * scale + 0.5)
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Print String(numStars, "*")
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Next
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End Sub
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basicStats 100
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Print
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basicStats 1000
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Print
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basicStats 10000
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Print
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basicStats 100000
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Print
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Print "Press any key to quit"
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Sleep
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