Identifying Missing Numbers in a Consecutive Series

Hello, nice array formula.Somehow is limited by the missing range ? I try it on a list with 22 numbers ( a range of 13 to 74, with gaps between 14 and 25 25 to 29 / 29 to 32..an so on).Formula show missing number till 34...and than empty for the other missing number..between 37 and 53 etc..
(see Figure 1 below)

@rr1024
Addendum to my previous comment - In case the number needs to be rounded, try this:
=IF(INT(B2+1.5)=INT(B3+0.5),"True","False")
or simply this:
=(INT(B2+1.5)=INT(B3+0.5))
By the way, Microsoft does work consistently, but not always as you expected.

@rr1024
You are assuming that the "1 minute counts" have no seconds. If they are derived from date serial numbers like NOW(), then they probably do. Try this:
=IF(INT(B2+1)=INT(B3),"True","False")

@rr1024
as your data I get TRUE, FALSE, FALSE which is correct. You have indicated that B4 = 3 which is the same as B3.

So B3 +1 will not = B4 so will be FALSE

You don't need the =sum element in your formula, =IF(B2+1=B3,"True","False") will work perfectly.

HTH

I have been trying to get this to work all day long and nothing works in excel for any of the IFs I create.
I have a simple list of numbers that represent 1 minute counts, so column B starts with B2=2, B3=3, B4=3 and in column A I have, starting in A3, =IF(SUM(B2+1)=B3,"True","FALSE")
=IF(SUM(B3+1)=B4,"True","FALSE")
=IF(SUM(B4+1)=B5,"True","FALSE")
I have FALSE, FALSE, FALSE column A and I should have True, True, False
Fundamentally this is probably way so many people hate Microsoft because it just does not work consistently.
The whole column is formated for whole numbers except the top header

Damian

The easiest way is to convert the data to a table by selecting a cell in the data and pressing Ctl + t. Table are dynamic and expand as data is added below. To convert it back to a range choose convert to range in the Tools section of the Table menu.

There is also an older method, it is not fully dynamic and it uses a couple of formulas.

=OFFSET(Sheet5!$A$2,0,0,COUNTA(Sheet5!$A$2:A500000),1)

A2 starts the range, they should alway have a Header. The two zeros refer to rows and columns to be offset, we do not want that. COunta counts the Rows with data and the range is limited to half a million to save Excel having to work too hard. The final 1 limits the range to just one column.

It is ages since I last used this method.

Peter

I am having trouble getting the missing numbers once I expand the range. My sequence begins with the number 97680 and ends with 198698. The min number is 97680 (A1) and the max number is 198698 (A99062). So when I revise the range to read A1:A99062 it does not work. Any ideas?

(see Figure 1 below) does anyone know how to identify the missing numbers if the data is listed in one column separated by a ","?

Lona
The formulas for the helper cells are:
=MIN (right(rng)+0) and
=Max(Right(range)+0)

Both are entered as Ctrl + Shift + Enter (CSE) and Excel wraps the formulas in curly brackets. In the code these are cells F3 and F4 and are the values for the variables M and N.

The last post was supposed to include a picture to make this clear, I'll try again.

(see Figure 1 below)

Lona,
The following needs two helper cells to get the min & max of the numbers; these are both array formulas. The code works up to numbers 999 and will need to be modified for numbers 1000 - 9999, 10000 - 99999 and so on.

Function AllThere(MyRange As Range)
Dim m As Integer, n As Integer
Dim There As Variant, i As Long, cell As Range
m = [f3]: n = [f4]

ReDim There(m To n)

On Error Resume Next
For Each cell In MyRange
There(Right(cell.Value, 3)) = 1
Next
On Error GoTo 0

AllThere = "Missing: "
For i = m To n
If Not There(i) = 1 Then
AllThere = AllThere & i & ", "
End If
Next i

If Len(AllThere) = 9 Then
AllThere = "All There"
Else
AllThere = Left(AllThere, Len(AllThere) - 2)
End If
End Function

{[fig}]

What if my numbers start with two letters, RC_100, RC_101

Further to my previous comment, the array formula may fail to identify some gaps.
If, for example, A1 contains 100 and the sorted list is from A1 to A135, the formula will not reveal any gaps greater than 235.
In other words, all gaps greater than (MIN(A1:A135) + 135) will be missed.

Mark
The UDF (User Defined Function) that I noted does not care about consecutive numbers. Works with any list of numbers.

Here is a handy little Macro from Mr Excel/ExcelisFun Dueling Excel. It even lists what number(s) is missing. Just set the amount of numbers in the list. In this case it is 1 to 99

Function AllThere(MyRange As Range)
Dim There(1 To 99) As Integer
On Error Resume Next
For Each cell In MyRange
There(cell.Value) = 1
Next
On Error GoTo 0

AllThere = "Missing: "
For i = 1 To 99
If Not There(i) = 1 Then
AllThere = AllThere & i & ", "
End If
Next i

If Len(AllThere) = 9 Then
AllThere = "All There"
Else
AllThere = Left(AllThere, Len(AllThere) - 2)
End If
End Function

Is there a way to check for missing numbers, if the list to search from is not in consecutive order?

I don't know what I'm doing wrong but if, for example, I create a list with 10 gaps, the copied formula is only finding the first 9. The last one always seems to be missing.

Jair

You can,, as stated in the last paragraph, copy the formula down to get the next value(s), When this is done, the Cell reference in the last part of the formula changes from Row(A1) to Row(A2) and the small value hence uses the fist then the second value.

{=IFERROR(SMALL(IF(COUNTIF($A$1:$A$135, MIN($A$1:$A$135)+ROW($1:$135)-1)=0, MIN($A$1:$A$135)+ROW($1:$135)-1),ROW(A1)),"")}
{=IFERROR(SMALL(IF(COUNTIF($A$1:$A$135, MIN($A$1:$A$135)+ROW($1:$135)-1)=0, MIN($A$1:$A$135)+ROW($1:$135)-1),ROW(A2)),"")}

How to display all missing numbers in one column?

If i paste this formula

=IFERROR(SMALL(IF(COUNTIF($A$1:$A$135,
MIN($A$1:$A$135)+ROW($1:$135)-1)=0,
MIN($A$1:$A$135)+ROW($1:$135)-1),ROW(A1)),"")

it will apears only the first missing number how about the next missing gap?

This is perfect! You have saved me a ton of time.

1st solution:
Put in B2 =IF($A2-$A1>column()-1,$A1+column()-1,"") and replicate.
Result:
row col.A col.B col.C col.D
1 -5
2 -1 -4 -3 -2
3 0
4 2 1
5 3

2nd solution:
Put in B2 =IF(A2-A1>1,A1+1&"-"&A2-1,"") and replicate.
Result:
row col.A col.B
1 -5
2 -1 -4--2
3 0
4 2 1-1
5 3