Question

I have data stored in some column (Say, Column A). The length of Column A is not fixed (depends on previous steps in the code).

I need a histogram for the values in Column A, and have it in the same sheet. I need to take the values in column A, and automatically compute M Bins, then give the plot.

I looked online for a “simple” code, but all codes are really fancy, with tons of details that I don’t need, to the extent that I am not even able to use it. (I am a VBA beginner.)

I found the following code that seems to do the job, but I am having trouble even calling the function. Besides, it only does computations but does not make the plot.

Sub Hist(M As Long, arr() As Single)
Dim i As Long, j As Long
Dim Length As Single
ReDim breaks(M) As Single
ReDim freq(M) As Single

For i = 1 To M
    freq(i) = 0
Next i

Length = (arr(UBound(arr)) - arr(1)) / M

For i = 1 To M
    breaks(i) = arr(1) + Length * i
Next i

For i = 1 To UBound(arr)
    If (arr(i) <= breaks(1)) Then freq(1) = freq(1) + 1
    If (arr(i) >= breaks(M - 1)) Then freq(M) = freq(M) + 1
    For j = 2 To M - 1
        If (arr(i) > breaks(j - 1) And arr(i) <= breaks(j)) Then freq(j) = freq(j) + 1
    Next j
Next i

For i = 1 To M
    Cells(i, 1) = breaks(i)
    Cells(i, 2) = freq(i)
Next i
End Sub

And then I try to call it simply by:

Sub TestTrial()
Dim arr() As Variant
Dim M As Double
Dim N As Range

arr = Range("A1:A10").Value
M = 10

Hist(M, arr)    ' This does not work.  Gives me Error (= Expected)
End Sub

Answer 1

Not 100% sure as to the efficacy of that approach but;

• Remove the parens as your calling a sub; Hist M, arr
• M is declared as double but received by the function as a long; this won’t work so declare it in the calling routine as long
• You will need to recieve arr() As Variant
• Range -> Array produces a 2 dimensional array so the elements are arr(1, 1) .. arr(n, 1)