问题
I'm following a tutorial:
http://dkowalski.com/blog/archive/2014/01/11/f-deedle-and-computational-investing.aspx
and when I try to apply normalization to all the columns of "stocks" Frame, using Frame.mapColValues, I obtain the following error message:System.InvalidOperationException: OptionalValue.Value: Value is not available
in Deedle.OptionalValue``1.get_Value() in c:\Tomas\Public\Deedle\src\Deedle\Common\Common.fs:riga 35
in FSI_0046.normalized@52-8.Invoke(ObjectSeries``1 os) in C:\Users\Bruno-Astarita\Documents\Visual Studio 2013\Projects\TestDeedle02\TestDeedle02\TestTutorial01.fsx:riga 52
in <StartupCode$Deedle>.$Series.f@257-13[K,V,R](Func``3 f, Int32 i, K key, V v) in c:\Tomas\Public\Deedle\src\Deedle\Series.fs:riga 358
in <StartupCode$Deedle>.$Series.newVector@354-1.Invoke(Int32 i, Tuple``2 tupledArg) in c:\Tomas\Public\Deedle\src\Deedle\Series.fs:riga 355
in Microsoft.FSharp.Collections.IEnumerator.mapi@129.DoMoveNext(b& )
in Microsoft.FSharp.Collections.IEnumerator.MapEnumerator``1.System-Collections-IEnumerator-MoveNext()
in Microsoft.FSharp.Collections.SeqModule.ToArray[T](IEnumerable``1 source)
in Microsoft.FSharp.Collections.ArrayModule.OfSeq[T](IEnumerable``1 source)
in Deedle.Series``2.Select[R](Func``3 f) in c:\Tomas\Public\Deedle\src\Deedle\Series.fs:riga 352
in Deedle.Series``2.Select[R](Func``2 f) in c:\Tomas\Public\Deedle\src\Deedle\Series.fs:riga 365
in Deedle.SeriesModule.MapValues[T,R,K](FSharpFunc``2 f, Series``2 series) in c:\Tomas\Public\Deedle\src\Deedle\SeriesModule.fs:riga 451
in <StartupCode$FSI_0046>.$FSI_0046.main@() in C:\Users\Bruno-Astarita\Documents\Visual Studio 2013\Projects\TestDeedle02\TestDeedle02\TestTutorial01.fsx:riga 49
Stopped due to error
I tried to find the problem making a step-by-step procedure based on source code in FrameModule.fs, and the error raises at the instruction Series.mapValues f.
Where I'm wrong?
Many thanks.
Update
After many tests, the problem seems be arised by the row let firstItem = osAsFloat.GetAt(0) from the tutorial. If I try to substitute it with let firstItem = 2.0 everything is ok. Still is not clear for me this behaviour.
回答1:
Finally I found the reason of problem. In some Series in the Frame, there are missing values in correspondence to the first element. If I do not use those Series, everything is ok.
来源：https://stackoverflow.com/questions/26116602/deedle-errors-using-frame-mapcolvalues