excel-d v0.0.1 - D API to write functions callable from Excel

[Laeeth Isharc via Digitalmars-d-announce]

C++ example for XLW:

  LPXLFOPER EXCEL_EXPORT xlStats(LPXLFOPER inTargetRange) {
         EXCEL_BEGIN;
         XlfOper xlTargetRange(inTargetRange);

         // Temporary variables.
         double averageTmp = 0.0;
         double varianceTmp = 0.0;

         // Iterate over the cells in the incoming matrix.
         for (RW i = 0; i < xlTargetRange.rows(); ++i)
         {
             for (RW j = 0; j < xlTargetRange.columns(); ++j)
             {
                 // sums the values.
                 double value(xlTargetRange(i,j).AsDouble());
                 averageTmp += value;
                 // sums the squared values.
                 varianceTmp += value * value;
             }
         }
         size_t popSize = xlTargetRange.rows() * 
xlTargetRange.columns();

         // avoid divide by zero
         if(popSize == 0)
         {
             THROW_XLW("Can't calculate stats on empty range");
         }

         // Initialization of the results Array oper.
         XlfOper result(1, 2);
         // compute average.
         double average = averageTmp / popSize;
         result(0, 0) = average;
         // compute variance
         result(0, 1) = varianceTmp / popSize - average * average;
         return result;
         EXCEL_END;
     }

D example (didn't get time to test, but something like this) is a 
little bit more concise! :
     import std.algorithm:map,sum;
     import std.range:front;

     @Register(ArgumentText("input range to calculate statistics 
for"),
         HelpTopic("excel-d"),
         FunctionHelp("calculates mean and variance for input 
array"),
         ArgumentHelp(["input range to calculate statistics for"]))
     auto xlStats(double[][] inTargetRange)
     {
         auto numCells = (inTargetRange.length > 0) ?
                                      inTargetRange.length * 
inTargetRange.front.length : 0;
         auto means = inTargetRange.map!(row => row.sum).sum / 
numCells;
         auto sumSquares = inTargetRange.map!( row => 
row.map!(cell => cell*cell).sum).sum;
         return [means, sumSquares / numCells - means];
     }