cfman

I think you will have to write a function to integrate the pdf
yourself.

Within a spreadsheet you can use the FREQUENCY() function on very
small partitions/bins to create the data via which you chart the pdf,
then doing a cumulative sum of the results will give a good
approximation of the cdf...works best on a large data set.

Within VBA I use the following functions to create a 2-d array of
breaks and frequencies...you could add a 3rd dimension to keep a
running total of the frequencies and chart that for the cdf.

Function Hist2(Breaks As Long, arr() As Double, Optional
FreqAsPercentage As Boolean = False)

'calculates bins and frequencies for an array
'       where Breaks = no. of breaks
'have to use the GetMax and GetMin functions as arr is likely to have
more than 65,535 elements

   Dim i As Long, j As Long, ArrSize As Double
   Dim length As Double
   Dim MaxValue As Double
   Dim MinValue As Double
   ReDim breaksNfreq(1 To Breaks, 1 To 2) As Double 'first column is
breaks, second is freq

   'Assign initial value for the frequency array
   For i = 1 To Breaks
       breaksNfreq(i, 2) = 0
   Next i

   MaxValue = GetMax(arr)
   MinValue = GetMin(arr)

   'Linear interpolation
   length = (MaxValue - MinValue) / Breaks
   For i = 1 To Breaks
       breaksNfreq(i, 1) = MinValue + length * i
   Next i

   'Counting the number of occurrences for each of the bins
   For i = LBound(arr) To UBound(arr)
       If (arr(i) <= breaksNfreq(1, 1)) Then breaksNfreq(1, 2) =
breaksNfreq(1, 2) + 1
       If (arr(i) >= breaksNfreq(Breaks - 1, 1)) Then
breaksNfreq(Breaks, 2) = breaksNfreq(Breaks, 2) + 1
       For j = 2 To Breaks - 1
           If (arr(i) > breaksNfreq(j - 1, 1) And arr(i) <=
breaksNfreq(j, 1)) Then
           breaksNfreq(j, 2) = breaksNfreq(j, 2) + 1
           Exit For
           End If
       Next j
   Next i

If FreqAsPercentage = True Then
   ArrSize = (UBound(arr) - LBound(arr) + 1)
       For i = 1 To UBound(breaksNfreq)
       breaksNfreq(i, 2) = breaksNfreq(i, 2) / ArrSize
       Next i
End If
   Hist2 = breaksNfreq()
End Function

Function GetMax(arr() As Double) As Double
Dim i As Long
Dim j As Long
Dim z As Long

i = LBound(arr)
j = UBound(arr)

GetMax = arr(i)
For z = i + 1 To j
   If arr(z) > GetMax Then GetMax = arr(z)
Next z
End Function

Function GetMin(arr() As Double) As Double
Dim i As Long
Dim j As Long
Dim z As Long

i = LBound(arr)
j = UBound(arr)

GetMin = arr(i)
For z = i + 1 To j
   If arr(z) < GetMin Then GetMin = arr(z)
Next z

Hope that helps
Lloyd

cfman  -

The Histogram in Excel's Analysis ToolPak has a checkbox for "Cumulative
Percentage."

You find it at Tools | Data Analysis | Histogram.

(For an alternative, see my free Better Histogram add-in at
www.treeplan.com.)

In general, a histogram is usually a column chart of a frequency
distribution, where the frequency distribution is summarizing real data.

For me, "CDF" usually means "Cumulative Distribution Function."

-  Mike
http://www.mikemiddleton.com

see:

http://groups.google.com/group/microsoft.public.excel.worksheet.functions/browse
_thread/thread/91ad10a71d2c7c23/57be32b7dc60cde8?lnk=st&q=Cumulative+Probability
+Density++group%3A*excel&rnum=7#57be32b7dc60cde8