private static IEnumerable <double> ExampleAveragePricesMerge()
{
var stockPrices = new[]
{
// IBM APL TIX NNTP
new[] { 10.0, 11.0, 15.0, 9.0 }, // day 1
new[] { 4.0, 3.8, 4.1, 3.1 }, // day 2
new[] { 9.0, 8.0, 18.3, 22.3 } // day 3
};
// sum the columns
var res = ZipEnumerable.Return(0.0); // provides an initial field to begin summing the
// columns against; merging against the
// rows in stockPrices will produce rows
// with the same length.
foreach (var day in stockPrices)
{
res = from pair in res.Merge(day)
select pair.Item1 + pair.Item2;
}
// result is the average of each column in a new row
var averagePrices = from sum in res
select(sum / stockPrices.Count());
return(averagePrices);
}
private static IEnumerable <double> ExampleAveragePricesLINQ()
{
var stockPrices = new[]
{
// IBM APL TIX NNTP
new[] { 10.0, 11.0, 15.0, 9.0 }, // day 1
new[] { 4.0, 3.8, 4.1, 3.1 }, // day 2
new[] { 9.0, 8.0, 18.3, 22.3 } // day 3
};
// sum the columns
var res = ZipEnumerable.Return(0.0); // provides an initial field to begin summing the
// columns against; merging against the
// rows in stockPrices will produce rows
// with the same length.
foreach (var day in stockPrices)
{
res = from
runningSum in res
join price in day
on 1 equals 1
// hacking join this way is the same as Merge(),
// meaning we will get runningSum at position x
// coupled with price at position x in the day
select runningSum + price;
}
// result is the average of each column in a new row
var averagePrices = from sum in res
select(sum / stockPrices.Count());
return(averagePrices);
}
