We all know VLOOKUP (or INDEX+MATCH) as an indispensable tool in our Excel toolbox. But what if you want the lookups to be a little gentler, nicer and relaxed?
Let’s say you want to lookup the amount $330.50 against a list of payments. There is no exact match, but if we look 50 cents in either direction, then we can find a match. Here is a demo of what I mean.
Unfortunately, you can’t convince VLOOKUP to act nice.
Hey VLOOKUP, I know you are awesome and all, but can you cut me some slack here?
VLOOKUP is tough, reliable and has a cold heart. Or is it?
In this post, let’s learn how to do lenient lookups.
Data for the problem
Let’s say you have a simple 2 column table like this. Our table is uninspiringly named data.
Lenient lookup – setting up the formula
Our input amount is in cell C3.
Let’s say when looking up for the amount, we want to follow this logic.
- If an exact match is found, return that
- Else, see if we can find anything with in 50 cents either side (you can change 50 to whatever you want)
- If nothing can be found, we want to return “Not found” or similar message
Formulas to use:
1: we can use good old INDEX+MATCH
2: we can use array based INDEX+MATCH
3: we can use IFERROR.
Let’s put everything together.
Our lenient lookup formula (array):
=IFERROR( INDEX(data[Client], IFERROR(MATCH($C$3,data[Amount],0), MATCH(1, (data[Amount]>($C$3-0.5))*(data[Amount]<($C$3+0.5)),0) ))
,"Not found")
How does it work?
Let’s go inside out.
MATCH($C$3,data[Amount],0): this formula simply looks for C3 in data[Amount] column and returns the position.
MATCH(1, (data[Amount]>($C$3-0.5))*(data[Amount]<($C$3+0.5)),0): This array formula checks for 1 (TRUE) by looking at data[Amount] between C3-0.5 and C3+0.5
The formula has two Boolean arrays multiplied and it returns a bunch of 1s & 0s.
MATCH then picks up the first such amount.
Inner IFERROR(MATCH(…), MATCH(…)): This acts like a fail-safe switch. If there is no exact match (first one), then lenient match (second one) will be used.
Outer IFERROR(): If no matches are found (exact or lenient) then “Not found” will be printed.
As this is an array formula, you need to press CTRL+Shift+Enter to get the result.
Related material – read these if you have questions about the formula techniques used above:
Other lenient / almost lookup problems
There are few more variations to this technique. Let’s review them.
Note: all of these are array formulas, so press CTRL+Shift+Enter.
Ignore decimal portion
We lookup just the whole number portion of the value to find match.
Formula: =INDEX(data[Client], MATCH(G7, INT(data[Amount]),0))
Notes on how it works:
- INT() turns data[Amount] column to whole numbers.
- We then lookup the amount (G7) and return the match
Amount is at least something, client name begins with S
Formula: =INDEX(data[Client], MATCH(1, (data[Amount]>=G8)*(LEFT(data[Client],1)=”S”),0))
- We use a different Boolean structure with >= and LEFT() formulas. The output will be a bunch of 1s & 0s.
- INDEX+MATCH for find the first such value (G8)
Closest Amount to input
This is interesting. We use MIN & ABS to find closest amount to input value (G10) and return the client’s name.
Formula: =INDEX(data[Client], MATCH(MIN(ABS(data[Amount]-G10)), ABS(data[Amount]-G10),0))
- ABS(data[Amount]-G10) gives a bunch of absolute (positive) values. The smallest of these will closest to G10.
- MIN() finds the smallest value
- MATCH looks up the minimum value from ABS(data[Amount]-G10)
- INDEX gives corresponding client’s name
Download lenient lookup example workbook
Click here to download the example workbook. The file contains sample data, several examples of these techniques and additional resources to learn. Give it a go.
More ways to lookup
Lookups are an essential part of any data analysis work you do in Excel. Pick up some nifty tricks from these links.
- Basics:
- Advanced:
Got a lookup tip to share?
Have some lookup stories to tell? I am listening. Please post them in comments.
12 Responses to “Speeding up & Optimizing Excel – Tips for Charting & Formatting [Speedy Spreadsheet Week]”
Usually when I dump data into my files to update values, the formatting sometimes go to all rows or columns. So what I typically will do is go to the last row and then the last column and use Ctrl + Shift + end and then delete the cells highlighted. this will remove all unknown formats in the worksheet. Also, after you have done this, you won't see the benefit until you save the document. Sometimes I even have to close and reopen. The direct sign that this has improved is the size of the scroll bar and range.
I have some comments on a couple of the points.
1. Camera objects
Tip: I use defined names in conjunction with camera tool objects.
Each camera object gets a name like so:
CameraItem01
Referring to: =IF(PicsOn=1,Sheet1!$C$2:$S$5,"")
By setting the PicsOn name to 1, the camera objects become "live", by setting the PicsOn name to 0, they become static. That improves performance enormously.
4: Conditional formatting
Lots of CF rules can slow down your workbook a lot. And it does not show the calc progress a "normal" recalc does on slow workbooks.
5. Format whole columns/rows
as far as I know, there is no problem with formatting entire columns/rows performance-wise, on the contrary, Excel is more efficient when you format an entire column than when you format a couple of 100 rows of a column.
6. Styles.
Here I wholeheartedly disagree. I say: Use styles. And use them religously.
I mean: if you have applied a (custom) style and you need to change a small piece of formatting to make that one cell look right, force yourself to create a new style just for that cell. It forces you to really think about your spreadsheet design and try and streamline it. It also makes it much, much easier to change your sheet's appearance later on. See http://www.jkp-ads.com/articles/styles00.asp
Very good insights Jan..
Camera objects: I often use similar technique to turn off images in my dashboards.
Formats: Thanks for clearing this. Do you think formatting larger ranges has any impact on macro speeds or it does not matter?
Styles: Thanks for telling us about this. As I mentioned, I am not sure about the styles, but I am under the impressions that excessive use of styles can bloat the file size.
@Chandoo:
If you stick to formatting entire rows/columns I don't expect macro speed is affected. Better: try it!
If you use styles properly AND as a replacement of ad-hoc cell formatting, I expect you'll see that the file actually is smaller in size.
This is because the cells now only have a reference to a single style instead of a reference to a custom cell formatting style.
Many cell formatting combinations get created if you format your cells in an ad-hoc manner, which was responsible for the dreaded "Too many different cell formats" error in Excel 2003 and older. Excel 2007 and 2010 have a higher limit there, but it does slow down your file with many of them.
Style bloat in my point of view is what you get by copying and pasting a lot from various other files and thus get Normal 1, Normal 1 1, Normal 1 1 1, ... I have seen workbooks with as many as 6000 styles, all caused by copying and pasting from various differently formatted workbooks.
Excel 2007 and 2010 have fixed a number of issues regarding copying of styles, but for workbooks with a long editing history, the trouble is already in the workbooks.
Cant emphasise the importance of reducing the amount of formatting in a workbook - this has a suprising impact on workbook size. I've always kept to one font, and no more than three colours - this has worked well for me. Keeping things clean and simple should be the motto when designing any type of report/dashboard that is going to be distributed around the organisation.
You can also save a few MB's by saving as an xlsb file.
Has anyone else mentioned that only the first item in the "more ..." section is hyperlinked.
Prem, have you confirmed by trial that XLSB file size is smaller than same XLSX file? Sorry, I just tried it with a small, simple XLSM file. I was surprised to see you are correct. File went from 40kb to 37kb. I thought that the compression of the new file would make the new file smaller.
@Ron
All Excel files have a minimum overhead that they have to include which is around 8KB, just to store a simple number or letter.
So with a small file of 40KB you will not see a huge improvement in file size
With files greater than 10MB you will see large improvements in size.
The compression gained also depends on what the contents of the file include. That is straight numbers, text and formulas can be greatly compressed whereas files that contain a lot of objects especially pictures gain very little from using *.xlsb files.
@Ron.. the other articles are yet to be published. All the links will be updated by Tuesday (27th March).
Hi,
I have a need for x,y scatter chart to have arround 30 data series.
like this:
http://i65.tinypic.com/jra8lc.jpg
Also I have multiple of such charts in one excel file.
Is there any way to make excel faster, because it is irritatingly slow?
(though my PC config. is quite on the level)
Thanks in advance!!!
@Mil
30 series won't be the issue
It is the number of points in the series
Also remove all fancy modifications, like shadows, fancy fills etc
I'd suggest asking the question in the Chandoo.org Forums http://forum.chandoo.org/
Attach a sample file with an example of what you are after
@Hui
I've already removed all fancy mod. The problem is there are also a lot of data points in one series.
Thanks for the advice!
@Mil
Do you really need every data point ?
Where is the chart being presented Screen or Report
On a screen you are unlikely to use more than 800 pixels for the chart area
So using any more than about 250 points is not adding values
On an A4 chart in landscape lets say the chart area is 6" long and at 300dpi that is 2000 pixels
Once again using more than 800-1000 points will not add any value
I have seen charts with 30,000+ points and when this is explained and a work around shown people appreciate the speed up
For a work around try setting up an area where you select say every x'th point using an Offset or Index Function
Then plot that data
I'd suggest asking the question in the Chandoo.org Forums http://forum.chandoo.org/
Attach a sample file with an example of what you are after