September Morn Update

Task/Van-der-Corput-sequence/00META.yaml

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+--- {}

Task/Van-der-Corput-sequence/Factor/van-der-corput-sequence.factor

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+USING: formatting fry io kernel math math.functions math.parser
+math.ranges sequences ;
+IN: rosetta-code.van-der-corput
+
+: vdc ( n base -- x )
+    [ >base string>digits <reversed> ]
+    [ nip '[ 1 + neg _ swap ^ * ] ] 2bi map-index sum ;
+
+: vdc-demo ( -- )
+    2 5 [a,b] [
+        dup "Base %d: " printf 10 <iota>
+        [ swap vdc "%-5u " printf ] with each nl
+    ] each ;
+
+MAIN: vdc-demo

Task/Van-der-Corput-sequence/Swift/van-der-corput-sequence.swift

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+func vanDerCorput(n: Int, base: Int, num: inout Int, denom: inout Int) {
+  var n = n, p = 0, q = 1
+
+  while n != 0 {
+    p = p * base + (n % base)
+    q *= base
+    n /= base
+  }
+
+  num = p
+  denom = q
+
+  while p != 0 {
+    n = p
+    p = q % p
+    q = n
+  }
+
+  num /= q
+  denom /= q
+}
+
+var num = 0
+var denom = 0
+
+for base in 2...5 {
+  print("base \(base): 0 ", terminator: "")
+
+  for n in 1..<10 {
+    vanDerCorput(n: n, base: base, num: &num, denom: &denom)
+
+    print("\(num)/\(denom) ", terminator: "")
+  }
+
+  print()
+}

Task/Van-der-Corput-sequence/VBA/van-der-corput-sequence.vba

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+Private Function vdc(ByVal n As Integer, BASE As Variant) As Variant
+    Dim res As String
+    Dim digit As Integer, g As Integer, denom As Integer
+    denom = 1
+    Do While n
+        denom = denom * BASE
+        digit = n Mod BASE
+        n = n \ BASE
+        res = res & CStr(digit) '+ "0"
+    Loop
+    vdc = IIf(Len(res) = 0, "0", "0." & res)
+End Function
+
+Public Sub show_vdc()
+    Dim v As Variant, j As Integer
+    For i = 2 To 5
+        Debug.Print "Base "; i; ": ";
+        For j = 0 To 9
+            v = vdc(j, i)
+            Debug.Print v; " ";
+        Next j
+        Debug.Print
+    Next i
+End Sub

Task/Van-der-Corput-sequence/Visual-Basic-.NET/van-der-corput-sequence.visual

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+Module Module1
+
+    Function ToBase(n As Integer, b As Integer) As String
+        Dim result = ""
+        If b < 2 Or b > 16 Then
+            Throw New ArgumentException("The base is out of range")
+        End If
+
+        Do
+            Dim remainder = n Mod b
+            result = "0123456789ABCDEF"(remainder) + result
+            n = n \ b
+        Loop While n > 0
+
+        Return result
+    End Function
+
+    Sub Main()
+        For b = 2 To 5
+            Console.WriteLine("Base = {0}", b)
+            For i = 0 To 12
+                Dim s = "." + ToBase(i, b)
+                Console.Write("{0,6} ", s)
+            Next
+            Console.WriteLine()
+            Console.WriteLine()
+        Next
+    End Sub
+
+End Module