fdo#71436 add Excel 2010 functions for F-distribution

Added F.DIST.RT, F.INV.RT, F.TEST, which are renamed
FDIST, FINV and FTEST and handle the right tail F-distribution.
Added F.DIST and F.INV, which are new functions and handle
the left tail F-distribution.

Change-Id: Ia7fa26a25f3188249f280733d6111951e2600704
Reviewed-on: https://gerrit.libreoffice.org/6701
Reviewed-by: Eike Rathke <erack@redhat.com>
Tested-by: Eike Rathke <erack@redhat.com>

1 files changed, 48 insertions, 0 deletions

diff --git a/sc/source/core/tool/interpr3.cxx b/sc/source/core/tool/interpr3.cxx
index 6272792be0a5..2f534f618249 100644
--- a/sc/source/core/tool/interpr3.cxx
+++ b/sc/source/core/tool/interpr3.cxx
@@ -1597,6 +1597,33 @@ void ScInterpreter::ScFDist()
     PushDouble(GetFDist(fF, fF1, fF2));
 }
 
+void ScInterpreter::ScFDist_LT()
+{
+    if ( !MustHaveParamCount( GetByte(), 4 ) )
+        return;
+    bool   bCum = GetBool();
+    double fF2 = ::rtl::math::approxFloor( GetDouble() );
+    double fF1 = ::rtl::math::approxFloor( GetDouble() );
+    double fF  = GetDouble();
+    if ( fF < 0.0 || fF1 < 1.0 || fF2 < 1.0 || fF1 >= 1.0E10 || fF2 >= 1.0E10 )
+    {
+        PushIllegalArgument();
+        return;
+    }
+    if ( bCum )
+    {
+        // left tail cumulative distribution
+        PushDouble( 1.0 - GetFDist( fF, fF1, fF2 ) );
+    }
+    else
+    {
+        // probability density function
+        PushDouble( pow( fF1 / fF2, fF1 / 2 ) * pow( fF, ( fF1 / 2 ) - 1 ) /
+                    ( pow( ( 1 + ( fF * fF1 / fF2 ) ), ( fF1 + fF2 ) / 2 ) *
+                      GetBeta( fF1 / 2, fF2 / 2 ) ) );
+    }
+}
+
 void ScInterpreter::ScChiDist()
 {
     double fResult;
@@ -2168,6 +2195,27 @@ void ScInterpreter::ScFInv()
     PushDouble(fVal);
 }
 
+void ScInterpreter::ScFInv_LT()
+{
+    if ( !MustHaveParamCount( GetByte(), 3 ) )
+        return;
+    double fF2 = ::rtl::math::approxFloor(GetDouble());
+    double fF1 = ::rtl::math::approxFloor(GetDouble());
+    double fP  = GetDouble();
+    if (fP <= 0.0 || fF1 < 1.0 || fF2 < 1.0 || fF1 >= 1.0E10 || fF2 >= 1.0E10 || fP > 1.0)
+    {
+        PushIllegalArgument();
+        return;
+    }
+
+    bool bConvError;
+    ScFDistFunction aFunc( *this, ( 1.0 - fP ), fF1, fF2 );
+    double fVal = lcl_IterateInverse( aFunc, fF1*0.5, fF1, bConvError );
+    if (bConvError)
+        SetError(errNoConvergence);
+    PushDouble(fVal);
+}
+
 class ScChiDistFunction : public ScDistFunc
 {
     ScInterpreter&  rInt;