Category Archives: Formulas

All about formulas and functions

Extracting Integers and Fractions in Microsoft Excel

Sometimes you need to extract the integer portion of a number. Sometimes the fractional part. Sometimes both. Excel makes it easy to get the integer and somewhat harder to get the fraction. If you just want the answer, skip to the technical details.

The Integer Part: Excel INT Function

What could be easier than the Excel INT function? I mean INT almost screams INTEGER. So the name is intuitive. You almost “know” what it’s going to do, even if you haven’t used it before.

With only one argument, it’s execution is even simpler. Just feed it a number and out pops the integer portion.

Below you can see I have the number 14.125 in cell D1 and the formula =INT(D1) returns the integer 14 in cell E1.
Excel INT Function

Date/Time Tip: A practical application for the INT function is to extract the date value from a date/time number. An example is a date/time value like 2/14/2013 9:04 AM in cell A2 and you only want the date. Using the formula =INT(A2) will strip out the time and leave the date 2/14/2013.

The Fractional Part

Here is where I would like some simplification. I mean, if we have the INT function for extracting an integer, you would think that there would be a FRAC function, or a simple name like that, to extract the fractional part.

If there was a FRAC function, you could also imagine that it would have only one argument. Just feed it a number and out pops the fraction. Simple. Elegant. Intuitive. No thought required. But, I digress.

To extract the fractional part of a number we can use the MOD function, which has not one, but two arguments. The reason it has two arguments is because it does more than extracting the fractional part. Forget about that.

Here is what you need to know about the MOD function and how to extract the fractional part of a number. The second argument of the MOD function is 1. Remember that. To reiterate, 1 is the second argument.

The first argument of the MOD function is the number. Shown below, you can see the number 14.125 in cell D1. The formula =MOD(D1,1) returns the fractional part 0.125 in cell E1.
MOD Function

Date/Time Tip: A handy way to extract a time value from a date/time number is to use the MOD function. Per our previous example, the date/time number 2/14/2013 9:04 AM in cell A2, the formula =MOD(A2,1) will return 9:04 AM.

Technical Details

Assume you have a number in cell A1.

To extract the integer value, use the formula:
=INT(A1)

To extract the fractional value, use the formula:
=MOD(A1,1)

MOD Function Time Extract

Extract Time with the MOD Function in Excel

I had a reader comment on my last post about how to extract time from a date-time number using the MOD function. Simple really.

The syntax is MOD(number,divisor). The MOD function returns the remainder after number is divided by divisor. A simple example is MOD(5,2), which equals one (1). It works like this: five (5) divided by two (2) equals two (2), with one (1) left over.

All numbers are evenly divisible by one (1) so the MOD function returns any fractional part when the second argument is one (1).

In the screen shot below, cell C2 has the Date-Time number: 10/8/12 6:28 PM. It has an underlying serial number: 41990.7698, which you can see in cell C3 with General formatting.

MOD Function Time Extract

Using the formula =MOD(C2,1) you can see the result in cells D2 and D3, with different cell formatting. Extracting the Time value from a Date-Time value is simple with the MOD function.

Break Even Calculation International Phone

Break Even Calculation with an Unlocked iPhone and International Rates

iPhone 4 PhotoI just upgraded my wife to a new iPhone 4S and since she’s finished with her contract, AT&T will now unlock her old iPhone 4.

Having an unlocked phone is advantageous when traveling overseas because you can pick up a Sim card with a phone plan and save some money. The question I want to answer here is, “Is it worth it?”

Phone Plans

I’ve spent time in the UK and the best place to get a Sim card or even buy an inexpensive mobile phone is with O2. Great coverage, products, service, and you can find them practically everywhere. Just what you need when “on Holiday” and are looking for a mobile phone plan.

With and unlocked iPhone you can pick up a Sim at O2 for £13.50 that gives you 100 minutes of talk, unlimited text, and 100MB of data. My phone plan with AT&T includes international roaming, which is free, but the international roaming rate in the UK is $1.39 per minute. Ouch!

The Conversion

The problem is that I need to convert British Pounds to American Dollars so I can make the comparison. You can find this information online with a search engine (Google, Bing, Yahoo). It would be nice if Microsoft would include currency conversion in the CONVERT function, but I digress.

The Calculation

Break Even Calculation International PhoneGiven a Sim only plan of £13.50, and a conversion rate of 1.6123 dollars per pound, my cost is $21.77 USD. That works out to $0.22 per minute, verses the $1.39 that AT&T will charge me while in the UK.

If I divide my cost in dollars, by the AT&T international rate in the UK, I can talk roughly 15 minutes on my AT&T plan before it becomes cost effective to purchase a Sim card.

The Smart Move

With a smart phone, data is king. So while it’s nice to consider the break even point for talk time on an international plan, the bottom line is that with 100MB of data in the aforementioned Sim plan on O2, there is no comparison.

When going on Holiday or spending time in the UK, pick up a Sim card and stick it in your unlocked iPhone. It’ll be the best spent money on the trip.

Horizontal Dynamic Dependent Drop Down List Example

A Dynamic Dependent Drop Down List with a Horizontal Table Reference

I received a comment asking if a dynamic dependent drop-down list in Excel could have a list where the “table headers were actually rows and not columns?” Since I’ve already detailed how this is done in the article mentioned above, I’ll keep this short. The screen shot below is what I’ll be referencing. At the end of the post I’ll give a link to the file I used.

Conditional Drop Down List (Excel)

Horizontal Dynamic Dependent Drop Down List Example

There are two named ranges,

    1. 1)

myCategoryH

    1. that refers to the range E1:E3 and

 

    1. 2)

myTableH

    that refers to range F1:G3.

A defined name, myItemListH, is created with the following formula =INDEX(myTableH,MATCH(Sheet1!A2,myCategoryH,0),0) that will return a row that is matched by the contents of cell A2.

In cell A2, add a Data Validation list with the source being =myCategoryH. In cell B2, add a Data Validation list with the source being =myItemListH in the conditional drop down list from Excel.

Now you’re done.

Cell A2 will give you a drop-down list of Fruit, Vegetables, or Other Stuff. And cell B2 will read the value in cell A2, match and return the proper row number, and return an array of values for that row.

Two Ways to Use the INDEX Function to Return an Array

This is a simple case of using the INDEX function in a slightly different way. Normally, to return column 2 of a named range, you would use the following formula =INDEX(myTable,0,2). The zero means: return all rows (of column 2).

If you want to return row 2 of the named range you would use =INDEX(myTable,2,0). Here the zero means: return all columns (of row 2).

This comes from the Help section of the INDEX function where in Excel 2011 it reads:

If you set row_num or column_num to 0 (zero), INDEX returns the array of values for the entire column or row, respectively. To use values returned as an array, enter the INDEX function as an array formula in a horizontal range of cells for a row, and in a vertical range of cells for a column. To enter an array formula, press ⌘+RETURN.

Practical Considerations

Adding to each category list across columns is problematic. For one thing adding more data to the table will require inserting a column within the table range to avoid renaming the range. Obviously a standard Excel “Table” won’t work with this type of list. And if you have a very large spreadsheet the number of columns will become limiting long before the number of rows would.

Download the File

Horizontal-Dynamic-Dependent-Drop-Down-List.xlsx

vlookup shark

The VLOOKUP Function – Inside Out

vlookup sharkAs part of Shark Week I’ve committed to write something for VLOOKUP week. (It’s what I get for using twitter.) So without further ado.

I love the VLOOKUP Function in Excel. As the name implies, it’s a vertical lookup. Meaning the function will lookup data in columns.

The VLOOKUP Function Arguments

The VLOOKUP function has four arguments and in my opinion the fourth argument always gets overlooked, yet it’s the first thing you need to know. So, like reverse polish notation, we’ll start from the inside and work out to explain each argument.

VLOOKUP(lookup_value,table_array,col_index_num,range_lookup)

range_lookup

The range lookup argument it either TRUE or FALSE. I use FALSE 98% of the time, because using FALSE means the VLOOKUP function will find an exact match. If no match is found then it returns the #N/A error value. Note: And by exact, they mean EXACT. An extra space character, which is not visible to the naked eye, will cause and error.

The strange thing is that you don’t even need the fourth argument, but if it’s missing the default value is TRUE. Bad choice by my estimation, but that because I rarely use TRUE. If the range lookup value is TRUE then the VLOOKP function will produce an approximate match.

This can be quite handy if you want to return something like grades, you know: A, B, C, D, F, when given a numerical value between 0 and 100. Teachers must love TRUE. The only catch here is that the first column of the lookup table has to be sorted in ascending order. You can find out more here.

col_index_num

This argument is just the column number from the table you are looking up. However, this column will contain the data you want the VLOOKUP function to return. For example, I have a table with Names in the first column and Cites in the second column. I want the VLOOKUP function to return the City value so the index number is 2, for the second column in the table.

table_array

The table is where VLOOKUP gets its information. This is where the data is looked up. The reference to the table may take several forms. You normally use an absolute range reference, like $A$1:$B$5. In Excel 2003 I like to use a defined Range Name. In newer versions of Excel I use a TABLE to store the information, and hence the Table Name is what I use for the second argument.

lookup_value

We finally come to the lookup_value. This is a single reference the VLOOKUP function uses to find a match in the first row of the Table. For example, if I want to lookup a Name and find the corresponding City, the lookup_value should reference a name and the first column of the table should be a column of names.

VLOOKUP Function in Action

In the screen shot below you can see the VLOOKUP function shown in the formula bar, which is for cell B2.

=VLOOKUP(A2,myTable,2,FALSE)

I’m using FALSE in the fourth argument for an exact match. For the third argument, I want to return data from column 2 of the Table, which is for the City. For the second argument, the reference is the Table name myTable, which is the range D1:E5. Finally, the the first argument, A2 is a reference to a name.

VLOOKUP Function Inside Out

So the VLOOKUP function in cell B2, looks in cell A2 and finds a name (Ted), then goes to the table, myTable, and locates an exact match in the first column (row 3), then goes over to the second column and returns that value (Bryan) to cell B2.

Note: The myTable reference refers to the range D2:E5, and doesn’t include the header row.

How to Update a List or Range without OFFSET

I avoid the use of Volatile Functions, especially OFFSET, which is commonly used to update a list or range. They can slow down the operation of your workbook. For very large workbooks with lots of data, it can be significant and irksome.

Worksheet cells that use Data Validation for a drop-down list can simplify the input process, or be used to limit the available choices. But the list needs be expandable. Here are two primary ways to keep your data validation list automatically updated, without having to resort to using the OFFSET function.

Update Your List Range with VBA

Put your data validation drop-down cell on one worksheet and the reference list range on another worksheet. Example: Sheet1 contains a cell with data validation. Sheet2 contains a data range (the list) that is given a defined name of myList. Add some VBA code in the Sheet2 Deactivate routine to update the named range.


Private Sub Worksheet_Deactivate()
Dim rng As Range
Set rng = Sheet2.Range("myList").CurrentRegion
Set rng = rng.Offset(1, 0).Resize(rng.Rows.Count - 1, rng.Columns.Count)
rng.Name = "myList"
End Sub

This is an event-based programming technique, which I commonly use with Excel 2003.

Data Validation List Lookup 1 Sheet

Use Some Table INDEX Magic

This is a variation of the same thing, but no VBA programming is warranted. Instead, use a Table for your reference list data. Then create a defined name with the INDEX Function, and use that name for the data validation list.

Tables automatically update their ranges when expanded and the INDEX function will too. Example: Create the defined name myListFormula and use =INDEX(Table1,0,1) as the formula. Then when setting the data validation list, use =myListFormula as the list reference.

Data Validation List Lookup 2 Sheet

Example Worksheet

I’ve put together a workbook with the two examples listed above. The first technique, with VBA, uses two worksheets: Lookup 1 and Data 1. The Data 1 worksheet has the VBA code, which updates the named range when deactivated. You can add or subtract to this list and the data validation list on the Lookup 1 sheet will automatically be updated.

Both Lookup sheets have data validation in cell A2, which is a list of names. I’ve added another column for the city that uses a formula to get the right value from the list.

Lookup 1 Sheet

Lookup 1 Sheet

Data 2 with VBA Code

Data 2 Sheet with VBA Code

The second example uses Lookup 2 and Data 2 worksheets. The Table is on the Data 2 worksheet. When you add or subtract data from this Table and the defined name myListFormula will automatically update the data validation list on the Lookup 2 worksheet. Be sure to look at the Define Name dialog box (on the Mac) or the Name Manager (Windows) to see the INDEX formula.

Define Name Dialog Box

Download the file: Data_Validation_List_Update.xlsm

Since there is no OFFSET function, updating at random intervals, in either of these examples, I can rest easy. That’s one less thing to slow down your worksheet.

Fill Down a Formula with VBA

I commented on a post that brought to light, the fact that, using the cell fill-handle to “shoot” a formula down a column doesn’t always work when the adjacent column(s) have blank cells. So I decided to share some Excel VBA code that’s used to copy a formula down to the bottom of a column of data.

The situation is depicted below. Cell C2 is active, and has the formula =B2+A2. I want to copy it down to the rest of the column in this data range. However, cells B6 and B11 are empty, along with countless others below the visible table range. (Pretend this data table is huge.)

Test Formula Fill Down BEFORE

Here is some VBA code that will Fill Down the formula.


Sub FillDownFormula()
'''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''
' Filldown a formula for in column of data.
' Assumes a data table with headings in the first row,
' the formula in the second row and is the active cell.
'''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''
Dim rng As Range
Dim rngData As Range
Dim rngFormula As Range
Dim rowData As Long
Dim colData As Long

' Set the ranges
Set rng = ActiveCell
Set rngData = rng.CurrentRegion

' Set the row and column variables
rowData = rngData.CurrentRegion.Rows.Count
colData = rng.Column

' Set the formula range and fill down the formula
Set rngFormula = rngData.Offset(1, colData - 1).Resize(rowData - 1, 1)
rngFormula.FillDown
End Sub

The key is setting the formula range (rngFormula). I take the entire region of data (rngData) and offset by 1 row because I don’t want the header row, then I resize the rows in the range by subtracting 1 from the total number of rows because I now need one less row in the range.

Next I offset the entire range by the row number of the active cell, but have to subtract one column because I offset from column 1, not column 0. And finally I resize the data range to 1 column, which gives me the single-column range I want with the formula in the top row.

The routine does no error checking and is restricted to using the active cell that has a formula. But it does the trick given those limitations.

International Short Date Formatting for the TEXT Function

I have an Excel workbook that is used in two different regions where the date format is entirely different, the US and the UK. At the top of a report worksheet I use a TEXT function to inform the user of the date range.

Here’s what a US user sees:

    From: 6/6/2011 to 6/10/2011

Here is the formula:

    =”From: ” & TEXT(MIN(ExtractData!A:A),”m/d/yyyy”) & ” to ” & TEXT(MAX(ExtractData!A:A),”m/d/yyyy”)

The Min and Max dates are in column A on a worksheet named ExtractData.

The problem is trying to automatically change the date format in the second argument of the TEXT Function – “m/d/yyyy” – which is a string argument. We can use VBA to accomplish this, but first a refresher on the TEXT function syntax.

TEXT Function Syntax and Argument

The Solution

The Application.International Property solves this problem with the xlMDY argument, which is TRUE if the date order is month-day-year, and FALSE if the date order is day-month-year. This property is put into the Workbook_Open event and modifies a defined name constant that’s used for the second argument of the TEXT function.

Here’s how it’s done.

Create a Defined Name Constant for the Date Format

I created a Defined Name Constant to store a Short Date format, and gave it the name sd_format.

In Excel 2007 and 2010, choose Formulas > Define Name to bring up the New Name dialog box where you type in sd_format in the Name box, and type =”m/d/yyyy” in the Refers to box. Remember the equals sign.

New Name dialog box

In Excel 2003, 2008, and 2011 choose Insert > Name > Define to bring up the Define Name dialog box. Type sd_format in the Names in workbook box, then type =”m/d/yyyy” in the Refers to box. Be sure to use the equals sign.

Substitute the Named Constant in the TEXT Function

The sd_format defined name can now be substituted for “m/d/yyy” in the second argument of the TEXT function. Here’s the new formula:

    =”From: ” & TEXT(MIN(ExtractData!A:A),sd_format) & ” to ” & TEXT(MAX(ExtractData!A:A),sd_format)

Since sd_format is already a text string, enclosed quotes are not needed.

Create a Workbook Open Routine

In the VBA Editor, I created a Workbook_Open subroutine, which looks at the computers international setting for the US, and if TRUE changes the sd_format value to “m/d/yyy”, and otherwise changes it to “d/m/yyyy” for the UK short date format.

Private Sub Workbook_Open()
''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''
' This routing updates the regional date setting format for the
' defined name sd_format.
'''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''
If Application.International(xlMDY) = True Then
ThisWorkbook.Names("sd_format").Value = "m/d/yyyy"
Else
ThisWorkbook.Names("sd_format").Value = "d/m/yyyy"
End If
End Sub

How it All Works

Each time the workbook is opened the Workbook_Open routine executes the IF-THEN-ELSE statement, which simply looks to see if the computers region setting is month-day-year, then sets the defined name sd_format to “m/d/yyyy” which is a US format. If the computer’s region setting for the long date format is NOT month-day-year (and presumably day-month-year) then sd_format is set to “d/m/yyyy” for the UK.

Every TEXT function using sd_format for the second argument will then have the proper short date format for that computer.

Note: Obviously if the region settings are changed on the computer while the file is open the file will have to be closed and reopened, but this would most likely be a rare occurrence.

A Dynamic Dependent Drop Down List

A Dynamic Dependent Drop Down List in Excel

A Dynamic Dependent Drop Down ListThe other day I was reading a post over at the Contextures blog about Dynamic Dependent Excel Drop Downs and realized that using an Excel Table would provide an alternative method that is both simple and flexible. Tables are available in Excel versions 2007, 2010, and 2011.

In this post I’ll create a Table to hold the Category’s and Items, create three defined names using dynamic formulas, then use Data Validation to create two drop-down lists, the second being dependent upon the first.

Create at Reference Table

Here’s a Table with Category names in the header row and Items in the columns. I just typed in the information then converted to a Table.

Category and Item Table

Create a Dynamic Defined Name for Category List

Create a defined name for the Table1 Header row range by using the formula =Table1[#Headers]. Please note that Table1 is the name of the Table created in the step above.

This defined name is dynamic, meaning it will expand when more columns are added and shrink if any columns are deleted. It will return the header row of the Table, which we’ll use in the next step. I used myCategory for this defined name.

Create Category Defined Name

To create a defined name in Windows choose Formulas > Name Manager then click New…. On a Mac choose Insert > Name > Define…. This will bring up the New Name dialog box that looks like the Edit Name screen-shot shown above.

Create a Category Drop Down List with Data Validation

Type Category in cell A1 for the column heading. Next select cell A2, then choose Data > Data Validation > Data Validation… and in the Data Validation dialog box (shown below) select List from the Allow box, then type in =MyCategory in the Source box, and click OK.

My Category Data Validation

Now cell A2 has a drop down button that shows the Header row of the Table. (Don’t worry about extending this Data Validation down to more rows, we’ll take care of that later.)

Category Drop Down List

Column B will hold a drop-down list for the Item, which is dependent upon the Category. This takes two defined names to work properly.

Create the First Defined Name for Items

[Update: Select cell B2 before you follow this next step.]
Create a defined name with the following formula:

=INDEX(Table1,0,MATCH(Sheet1!A2,Table1[#Headers],0))

that I’ll name myItemList.

My Item List Defined Name

This formula will return a reference to the Table column that matches the Category selection in cell A2 on Sheet1.

If I use Data Validation to create a drop-down list with the myItemList defined name I’ll get eight items returned because Table1 has eight data rows. As you can see in the picture below, the Vegetables item list has two blank lines, and the Other Stuff item list has one blank line.  Not an elegant solution.

Table Column Full List

However, if you have a table that always has equal items (rows) in each column then this defined name formula will will work well for a Data Validation list.

Create a Second Defined Name for Items

We can create a second defined name that will give us a dynamic list with the exact count. The following OFFSET formula will do the trick.

=OFFSET(myItemList,0,0,COUNTA(myItemList),1)

This formula uses the first defined name (myItemList) but alters the height by counting the items. I named this defined name myItem, as you can see below in the Name Manager screen shot.

Name Manager for myList

Create an Item Drop Down List with Data Validation

Type Item in cell B1. Select cell B2 and open the Data Validation dialog box. Choose List and enter the following formula =myItem, then click OK.

Data Validation Item List

The result is a dynamic drop-down list in the Item column that’s dependent on the Category selection in column A, and returns the exact list.

Dynamic Dependent Drop Down List

Convert to a Table

Now it’s time to covert this to a Table, and by doing so the Data Validation will be preserved and automatically expand with the addition of more rows.

Select cell A2, then in Windows (Excel 2007, 2010) choose Insert > Table, verify the information in the Create Table dialog box, and click OK.

Create Table in Windows

On a Mac (Excel 2011), select cell A2 then choose Tables > New > Insert Table with Headers.

At this point I normally turn off the Data Filter because it’s rather annoying.

As your Table expands, with more rows or columns, this dynamic drop-down list will work just fine. To create a new row in the Table with Data Validation press the Tab key while the active cell is the last column of the last row.

Potential Problem with OFFSET

As you might have guessed the OFFSET formula depends on having items at the top of the list. Should your data have blank rows in the middle of the column, the drop-down won’t have all the items listed yet show blank cells in the list.

Blank Cells and Missing Data

In this case it’s best to use the first defined name (myItemList) in creating a dependent, drop-down list for Item. At least you’ll get all the data, even if it does have some blanks in the list.

Blank Cells and No Missing Data

Reference Table Location

For illustration purposes I’ve shown the reference Table on the same worksheet as the Category and Item Table. Normally I would place the reference Table on a different worksheet. In this instance none of the formulas would change.

[UPDATE]

I’ve had numerous questions about the details of this post so I’m putting a link here to download the file.

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