The trouble is, you can't always guarantee that the users PC has an internet connection. So, what's the best approach to the problem? Well, check the internet connection using the handy bit if VBA code below!

Private Declare Function InternetGetConnectedStateEx Lib "wininet.dll" (ByRef lpdwFlags As Long, ByVal lpszConnectionName As String, ByVal dwNameLen As Integer, ByVal dwReserved As Long) As Long
 
'Testing for internet connection
Public Function IsInternetConnected() As Boolean
 
Dim strConnType As String
Dim lngReturnStatus As Long
 
    IsInternetConnected = False
    lngReturnStatus = InternetGetConnectedStateEx(lngReturnStatus, strConnType, 254, 0)
    If lngReturnStatus = 1 Then IsInternetConnected = True
 
End Function

This tip was sparked by a colleague's question the other day, and since I'd recently used the technique in a risk register tool, I thought there might be many others out there wondering how best to lookup matrix values.

The premise is that you have a two dimensional matrix of values and you want to retrieve a value from the matrix, given that you know the input values for the two dimesions of the matrix.

So, here's your matrix.. 

The matrix of values

 and here's what your after in your results table..

Matrix lookup results

 The method uses a combination of the INDEX and MATCH functions to give:

=INDEX(MatrixRange,MATCH(RowValueLookup,RowCategories,0),MATCH(ColumnValueLookup,ColumnCategories,0))

You also might have the situation where you have a numerical scale that you classify with banded categories (instead of fixed categories). In this situation your matrix might look like this..

Matrix with banded categories

For the solution to the second problem check out the attached file below. Looking at how both types of matrix lookup are implemented will explain it far better than me rabbiting on about it... i.e. I'm being lazy.

Here we have some data I made earlier... a table of order data and a list of orders.

Sample data

What we’re aiming to do is create a magical Scrolling Dynamic Lookup window to add to our equally awesome report, like so:

Scrolling Dynamic Lookup

In order to make our life that little bit easier – and to help you understand the formulas – I first created some Named Ranges, just like the ones below.

Creating Named Ranges

The next step is to create the structure for our scrolling ‘window’. This repeats the column headings from the order data table and adds an additional Item column, which the dynamic lookup formulas will reference.

Scrolling Dynamic Lookup structure

In D2 we need to create a Data Validation rule that provides the drop down filter to select the particular order that will be displayed. As you can see below, this references one of the Named Ranges we already setup:

Data validation for filtering

In case you’re wondering where the vertical scroll bar came from, this is a Form control that was added using the developer tab.

Adding the vertical scrollbar

NB: If you can’t see the developer tab, you need to turn it on by opening the Excel Options form (Office Button > Excel Options). In the Popular tab you need to check Show Developer tab in the Ribbon.

In order to complete the setup of the vertical scrollbar, right click on the scrollbar object and select Format Control; you should now see the following form:

Setup the scrollbar

The key parameter is the Cell link, which needs to refer to B4. You can also modify other parameters that will affect how the scrollbar operates. For example, I set a Maximum value of 50, but if I had any orders that had more than 54 products (50 plus the 4 rows below the first row), they wouldn’t all be displayed. To make this truly automated, the next step would be to add some VBA code to update the Maximum value based on the maximum order size, but that’s for another time.

Now we have the scrolling window created, all we have to do is throw in the magical Array formula in C4 and copy to all remaining cells (remembering to hold CTRL + SHIFT while we hit ENTER!):

={IFERROR(INDEX(DataTable,SMALL(IF(DataTable=$D$2,ROW(DataTable)),$B4),MATCH(C$3,DataTableHeaders,0)),"")}

Some explanation...

The MATCH function returns the column number in the order data table
MATCH(C$3,DataTableHeaders,0)

The SMALL function returns the column number in the order data table. This utilises the Order ID filter that we created in D2 and helps to make the formula dynamic. This is the Array part of the formula requiring CTRL+SHIFT+ENTER.
SMALL(IF(DataTable=$D$2,ROW(DataTable)),$B4)

The index function returns the value from the order data table using the column and row number that the SMALL and MATCH functions have returned.
 INDEX(DataTable,SMALL(...),MATCH(...))

Finally surrounding our INDEX function with the IFERROR function, allows us to show nothing if the INDEX function returns an error when no value exists.
IFERROR(INDEX(...),"")

Depending on how you need to implement this in a report, there are a number of tweaks you can perform from simple formatting, to removing unnecessary columns or increasing the number of rows in the Dynamic Scrolling Lookup.

Now, download and get learning!

Scrolling Dynamic Lookup
Scrolling Dynamic Lookup.xlsx
Version: Excel 2007

Excel 2007 example of a Scrolling Dynamic Lookup.

Author:	Chris Read
Category:	Post Files
License:	GNU General Public License
Date:	July 22, 2011

12.9 KiB
74 Downloads
Details...

The key technique employed utilises Array formulas, which I won’t go into detail about, mainly because plenty before me have (see links below). The quick 'how-to' is that you need to hold down the CTRL & SHIFT keys when pressing ENTER to commit the formula, instead of just hitting ENTER. Their other common name is a ‘CSE formula’ (Control, Shift, Enter). When committed, the formula is surrounded by curly {brackets}.

There are plenty of useful guides out there for Array formulas, including:

• http://www.cpearson.com/excel/ArrayFormulas.aspx
• http://www.mrexcel.com/articles/CSE-array-formulas-excel.php
• http://www.ozgrid.com/Excel/arrays.htm

So, here’s the sample data to show you the technique (not necessarily sorted by Supplier, as is the case below)...

Sample data

And here’s what we want to end up with in our complex transpose result...

Complex Transpose result

In order to obtain this result we need to throw the following functions into the mixing bowl...

• IFERROR – for cleaning up when we run out of product IDs.
• INDEX – for returning the Product ID from a specified row.
• SMALL – for returning the k-th smallest number in an array.
• ROW – for returning the row number of each Supplier.
• COLUMN – for calculating the column number in the output table.

Throwing them into cell E2 - beating with a whisk while adding water - gives the following scary combination...

={IFERROR(INDEX($B$2:$B$11,SMALL(IF($A$2:$A$11=$D2,ROW($A$2:$A$11)-1),COLUMN()-COLUMN($D2))),"")}

Time to dissect and see what we have!

This part gets the row number we're after in the Supplier Range
SMALL(IF(SupplierRange=SupplierName,ROW(SupplierRange)-1),COLUMN()-COLUMN(SupplierName))

The row number is then used to get the Product ID for that row
INDEX(ProductRange, SMALL(...))

We then trap any errors when a Product ID doesn't exist for the given column of the results
IFERROR(INDEX(...),"")

NB: The IF function is the array formula part, which requires CSE.

Simple right? Well, probably not at first glance. I find the best way to learn is to get your hands dirty, so download the sample file below and get learning!

I’ve included versions for Excel 2003 and 2007, because the IFERROR function didn’t exist in Excel 2003. Therefore the 2003 version utilises the IF(ISERROR()) workaround. See my last post about replacing these if you’re interested.

Complex Transpose
Complex Transpose.xlsx
Version: Excel 2007

Excel 2003 example file showing a complex transpose formula.

Languages:	English
Author:	Chris Read
Category:	Post Files
License:	GNU General Public License
Date:	July 13, 2011

10.2 KiB
66 Downloads
Details...

Complex Transpose
Complex Transpose.xls
Version: Excel 2003

Excel 2003 example file showing a complex transpose formula.

Languages:	English
Author:	Chris Read
Category:	Post Files
License:	GNU General Public License
Date:	July 13, 2011

23.5 KiB
34 Downloads
Details...

In Excel 2007, trapping and handling errors in a formula was made easier with the introduction of the IFERROR function, which removed the need to specify your formula twice, e.g. =IFERROR(MyFormula,ReturnSomethingElse).

With organisations upgrading to Office (Excel) 2007 at different times, compatibility can become an issue. Although installing the Microsoft Office Compatibility Pack will enable users of previous versions of Excel to open an Excel 2007 file, you can't rely on this being installed. Also, you may want to convert an Excel 2007 file to a previous version for people to use / modify; In Excel 2007, simply 'saving as' an older version (e.g. saving an 'xlsx' as an 'xls' file) will often bring up a load of compatibility warning messages, which aren't fixed automatically.

Through my need to develop in all versions of Excel, I developed a handy procedure (ReplaceIFERRORCellFormulas) that will convert a range of selected cells that contain IFERROR formulas to instead use a combination of the IF and ISERROR functions. There's also a procedure to check all Named Ranges (ReplaceIFERRORNamedRangeFormulas), in case you use them to store formulas.

modReplaceIFERROR.bas
modReplaceIFERROR.bas
Version: 1.0

Module containing a handy procedure (ReplaceIFERRORCellFormulas) that will convert a range of selected cells that contain IFERROR formulas to instead use a combination of the IF and ISERROR functions. There's also a procedure to check all Named Ranges (ReplaceIFERRORNamedRangeFormulas), in case you use them to store formulas.

Languages:	English
Author:	Chris Read
Category:	VBA Modules
License:	GNU General Public License
Date:	January 28, 2010

7.5 KiB
214 Downloads
Details...

Excel 2002 VBA: Programmers Reference
This was the first book I bought on Excel VBA and it has served me well. It covers a broad subject base for both beginner and expert Excel programmer, and for a reference book, has a detailed index for subject lookup.

Professional Excel Development: The Definitive Guide to Developing Applications Using Microsoft Excel and VBA
This book is more for the expert developer and looks at creating professional applications in Excel. The book shows Excel as more than just a spreadsheet tool, its a development platform. I would say it's a must for the serious Excel developer.

Professional Excel Development (2nd Edition): The Definitive Guide to Developing Applications Using Microsoft Excel and VBA
An updated version of the best book on the market for Excel developers. Extremely useful for the latest versions (2007 onwards) of Excel.