Add leap year utility functions

beutlich · Apr 11, 2020 · ff73f81 · ff73f81
1 parent 9153b94
commit ff73f81
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Showing 2 changed files with 84 additions and 1 deletion.
diff --git a/Modelica/Utilities/Time.mo b/Modelica/Utilities/Time.mo
@@ -27,6 +27,73 @@ now = getTime()   // = Modelica.Utilities.Types.TimeType(281, 30, 13, 10, 15, 2,
 <p>This function is impure!</p>
 </html>"));
   end getTime;
+
+  function isLeapYear "Check if a year is a leap year"
+    extends Modelica.Icons.Function;
+    input Integer year "Year";
+    output Boolean isLeap "= true, if year is a leap year";
+  algorithm
+    isLeap := (mod(year, 4) == 0 and mod(year, 100) <> 0) or mod(year, 400) == 0;
+    annotation (Documentation(info="<html>
+<h4>Syntax</h4>
+<blockquote><pre>
+isLeap = Time.<strong>isLeapYear</strong>(year);
+</pre></blockquote>
+<h4>Description</h4>
+<p>
+Checks if a given year is a leap year.
+</p>
+</html>"));
+  end isLeapYear;
+
+  function leapDays "Return the number of leap days in range"
+    extends Modelica.Icons.Function;
+    input Integer year1 "First year";
+    input Integer year2 "Second year";
+    output Integer days "Number of leap days in range [year1, year2 - 1]";
+  protected
+    Integer d "Length of range";
+    Integer y1;
+    Integer y2;
+  algorithm
+    d := year2 - year1;
+    if d == 0 then
+      days := 0;
+      return;
+    elseif d < 0 then
+      y1 := year2;
+      y2 := year1;
+      d := -d;
+    else
+      y1 := year1;
+      y2 := year2;
+    end if;
+    days := div(d - 1, 4) - div(d - 1, 100) + div(d - 1, 400);
+    if isLeapYear(y1) or isLeapYear(y2 - 1) then
+      days := days + 1;
+    end if;
+    if year1 > year2 then
+      days := -days;
+    end if;
+    annotation (Documentation(info="<html>
+<h4>Syntax</h4>
+<blockquote><pre>
+days = Time.<strong>leapDays</strong>(year1, year2);
+</pre></blockquote>
+<h4>Description</h4>
+<p>
+Returns the number of leap days in the range [<code>year1</code>, <code>year2</code> - 1].
+In case of <code>year1</code> &gt; <code>year2</code>, the result is the negative number of leap days in range [<code>year2</code>, <code>year1</code> - 1].
+</p>
+<h4>Example</h4>
+<blockquote><pre>
+days = leapDays(2000, 2020) // = 5 leap days in range [2000, 2019]
+                            // for the years 2000, 2004, 2008, 2012 and 2016
+                            // excluding the second year 2020
+</pre></blockquote>
+</html>"));
+  end leapDays;
+
     annotation (
 Documentation(info="<html>
 <p>

diff --git a/ModelicaTest/Utilities.mo b/ModelicaTest/Utilities.mo
@@ -374,7 +374,7 @@ extends Modelica.Icons.ExamplesPackage;
     Streams.print("... Test of Modelica.Utilities.System");
     Streams.print("... Test of Modelica.Utilities.System", logFile);
 
-    pid :=Modelica.Utilities.System.getPid();
+    pid := Modelica.Utilities.System.getPid();
     Streams.print("    pid  = " + String(pid));
 
     ok := true;
@@ -401,6 +401,20 @@ extends Modelica.Icons.ExamplesPackage;
     Streams.print("    mon  = " + String(now.mon));
     Streams.print("    year = " + String(now.year));
 
+    assert(not Modelica.Utilities.Time.isLeapYear(1900), "Time.isLeapYear failed");
+    assert(Modelica.Utilities.Time.isLeapYear(2000), "Time.isLeapYear failed");
+    assert(not Modelica.Utilities.Time.isLeapYear(2019), "Time.isLeapYear failed");
+    assert(Modelica.Utilities.Time.isLeapYear(2020), "Time.isLeapYear failed");
+
+    assert(0 == Modelica.Utilities.Time.leapDays(2000, 2000), "Time.leapDays failed");
+    assert(5 == Modelica.Utilities.Time.leapDays(2000, 2020), "Time.leapDays failed");
+    assert(-5 == Modelica.Utilities.Time.leapDays(2020, 2000), "Time.leapDays failed");
+    assert(5 == Modelica.Utilities.Time.leapDays(-2020, -2000), "Time.leapDays failed");
+    assert(98 == Modelica.Utilities.Time.leapDays(1600, 2001), "Time.leapDays failed");
+    assert(97 == Modelica.Utilities.Time.leapDays(1601, 2001), "Time.leapDays failed");
+    assert(97 == Modelica.Utilities.Time.leapDays(1600, 2000), "Time.leapDays failed");
+    assert(96 == Modelica.Utilities.Time.leapDays(1601, 2000), "Time.leapDays failed");
+
     ok := true;
   end Time;
 
@@ -507,6 +521,8 @@ extends Modelica.Icons.ExamplesPackage;
     result := ModelicaTest.Utilities.Streams(logFile);
     result := ModelicaTest.Utilities.Files(logFile);
     result := ModelicaTest.Utilities.Internal(logFile);
+    result := ModelicaTest.Utilities.System(logFile);
+    result := ModelicaTest.Utilities.Time(logFile);
     ok := true;
   end testAll;