Data commit

Task/Convert-decimal-number-to-rational/VBA/convert-decimal-number-to-rational.vba

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+Function Real2Rational(r As Double, bound As Long) As String
+
+If r = 0 Then
+    Real2Rational = "0/1"
+ElseIf r < 0 Then
+    Result = Real2Rational(-r, bound)
+    Real2Rational = "-" & Result
+Else
+    best = 1
+    bestError = 1E+99
+    For i = 1 To bound + 1
+        currentError = Abs(i * r - Round(i * r))
+        If currentError < bestError Then
+            best = i
+            bestError = currentError
+            If bestError < 1 / bound Then GoTo SkipLoop
+        End If
+    Next i
+SkipLoop:
+    Real2Rational = Round(best * r) & "/" & best
+End If
+End Function
+
+Sub TestReal2Rational()
+Debug.Print "0.75" & ":";
+For i = 0 To 5
+    Order = CDbl(10) ^ CDbl(i)
+    Debug.Print " " & Real2Rational(0.75, CLng(Order));
+Next i
+Debug.Print
+
+Debug.Print "0.518518" & ":";
+For i = 0 To 5
+    Order = CDbl(10) ^ CDbl(i)
+    Debug.Print " " & Real2Rational(0.518518, CLng(Order));
+Next i
+Debug.Print
+
+Debug.Print "0.9054054" & ":";
+For i = 0 To 5
+    Order = CDbl(10) ^ CDbl(i)
+    Debug.Print " " & Real2Rational(0.9054054, CLng(Order));
+Next i
+Debug.Print
+
+Debug.Print "0.142857143" & ":";
+For i = 0 To 5
+    Order = CDbl(10) ^ CDbl(i)
+    Debug.Print " " & Real2Rational(0.142857143, CLng(Order));
+Next i
+Debug.Print
+
+Debug.Print "3.141592654" & ":";
+For i = 0 To 5
+    Order = CDbl(10) ^ CDbl(i)
+    Debug.Print " " & Real2Rational(3.141592654, CLng(Order));
+Next i
+Debug.Print
+
+Debug.Print "2.718281828" & ":";
+For i = 0 To 5
+    Order = CDbl(10) ^ CDbl(i)
+    Debug.Print " " & Real2Rational(2.718281828, CLng(Order));
+Next i
+Debug.Print
+
+Debug.Print "-0.423310825" & ":";
+For i = 0 To 5
+    Order = CDbl(10) ^ CDbl(i)
+    Debug.Print " " & Real2Rational(-0.423310825, CLng(Order));
+Next i
+Debug.Print
+
+Debug.Print "31.415926536" & ":";
+For i = 0 To 5
+    Order = CDbl(10) ^ CDbl(i)
+    Debug.Print " " & Real2Rational(31.415926536, CLng(Order));
+Next i
+End Sub