September 2017 Update

Task/Convert-decimal-number-to-rational/Kotlin/convert-decimal-number-to-rational.kotlin

@@ -0,0 +1,29 @@
+// version 1.1.2
+
+class Rational(val num: Long, val den: Long) {
+    override fun toString() = "$num/$den"
+}
+
+fun decimalToRational(d: Double): Rational {
+    val ds = d.toString().trimEnd('0').trimEnd('.')
+    val index = ds.indexOf('.')
+    if (index == -1) return Rational(ds.toLong(), 1L)
+    var num = ds.replace(".", "").toLong()
+    var den = 1L
+    for (n in 1..(ds.length - index - 1)) den *= 10L
+    while (num % 2L == 0L && den % 2L == 0L) {
+        num /= 2L
+        den /= 2L
+    }
+    while (num % 5L == 0L && den % 5L == 0L) {
+        num /= 5L
+        den /= 5L
+    }
+    return Rational(num, den)
+}
+
+fun main(args: Array<String>) {
+    val decimals = doubleArrayOf(0.9054054, 0.518518, 2.405308, .75, 0.0, -0.64, 123.0, -14.6)
+    for (decimal in decimals)
+        println("${decimal.toString().padEnd(9)} = ${decimalToRational(decimal)}")
+}

Task/Convert-decimal-number-to-rational/REXX/convert-decimal-number-to-rational-3.rexx

@@ -50,8 +50,7 @@ test:
   Else
     tag='should be' soll
   say zin '=' fract tag
-  -- Say left(zz/nn,60)
-  Return
+   Return
 
 GCD: procedure
 /**********************************************************************

Task/Convert-decimal-number-to-rational/Ruby/convert-decimal-number-to-rational-2.rb

@@ -1,5 +1,4 @@
-> [0.9054054, 0.518518, 0.75].each { |d| puts "%s %s" % [d, Rational(d).rationalize(0.0001)] }
-0.9054054 67/74
-0.518518 14/27
-0.75 3/4
-=> [0.9054054, 0.518518, 0.75]
+[0.9054054, 0.518518, 0.75].each { |f| puts "#{f} #{f.rationalize(0.0001)}" }
+# =>0.9054054 67/74
+# =>0.518518 14/27
+# =>0.75 3/4

Task/Convert-decimal-number-to-rational/Zkl/convert-decimal-number-to-rational-1.zkl

@@ -0,0 +1,14 @@
+fcn real2Rational(r,bound){
+   if (r == 0.0) return(0,1);
+   if (r < 0.0){
+      result := real2Rational(-r, bound);
+      return(-result[0],result[1]);
+   } else {
+      best,bestError := 1,(1.0).MAX;
+      foreach i in ([1 .. bound + 1]){
+         error := (r*i - (r*i).round()).abs();
+	 if (error < bestError) best,bestError = i,error;
+      }
+      return((r*best).round().toInt(),best);
+   }
+}

Task/Convert-decimal-number-to-rational/Zkl/convert-decimal-number-to-rational-2.zkl

@@ -0,0 +1,9 @@
+tests := T(0.750000000,  0.518518000, 0.905405400,
+	   0.142857143,  3.141592654, 2.718281828,
+	  -0.423310825, 31.415926536);
+foreach r in (tests) {
+   print("%8.9f  ".fmt(r));
+   foreach i in (6)
+      { print("  %d/%d".fmt(real2Rational(r,(10).pow(i)).xplode())) }
+   println();
+}