4

I don't know how to properly describe what I need to do, so I will give an example. A colleague has a data set in Excel like so:

Col A    Col B    Col C
aaaaa    aaaaa    bbbbb
bbbbb    ccccc    ccccc
ccccc    ddddd    eeeee

The end result should be something like this:

Col A    Col B    Col C
aaaaa    aaaaa
bbbbb             bbbbb
ccccc    ccccc    ccccc
         ddddd
                  eeeee

Or even:

      Col A    Col B    Col C
aaaaa Yes      Yes      No
bbbbb Yes      No       Yes

etc.

(if it helps, the columns are protein extraction methods and the letters are protein IDs - we need to determine which proteins are extracted by which methods)

My colleague is doing this by hand, but there is enough data that it would be really helpful to automate it.

Is there a formula in Excel to do this automatically?

  • Can we assume, that each input column is sorted (sorting doesn't need to be alphabetical, but must be the same for all columns)? – Adam Ryczkowski Sep 26 '12 at 7:54
  • Is number of columns (=3) fixed? – Adam Ryczkowski Sep 26 '12 at 7:55
  • @AdamRyczkowski I believe the input column is sorted alphanumerically. The number of columns is not fixed (the file my colleague showed me has 5). – Lenna Sep 26 '12 at 18:06
  • It is possible to do it entirely with formulas. It will not be that easy as Scott's method. Because it will be done in formulas, the result will be 100% automated so there will be no need for any mouse clicks - only change input data. If you are interested let me know and I'll post it. – Adam Ryczkowski Sep 26 '12 at 20:36
  • @AdamRyczkowski: I have found formulas to get unique values from multiple columns, but I think copy and pasting will work well enough. – Lenna Sep 28 '12 at 18:06
3

This is not a “turn-key” solution, but if you have thousands of rows, this may save you some effort.  (Do this in a scratch copy of your file, just in case something blows up or melts down, because “Undo” doesn’t always work.)  Note: this procedure was developed for Excel 2007 (but I have re-verified it in Excel 2013).

First, copy all your data into a scratch column; let’s call it V.  Note that you must copy the heading from Column A, or else put some dummy value in cell V1.

Illustration of copying data

Now go to the “Data” tab, “Sort & Filter” group, and click on “Advanced”:

                        “Sort & Filter” group, with “Advanced” highlighted

This will bring up the “Advanced Filter” dialog box:

                  “Advanced Filter” dialog box

Verify that “List range” shows your data in Column V.  Select “Copy to another location” and “Unique records only”.  Type “W1” in the “Copy to” field — or click in the field, and then click in W1 (there are several techniques that will get the same result).  Click on “OK”.  You should get something like this:

                              Data from V copied into W with duplicates removed

i.e., a list of your unique data values.  You may need to sort Column W.

Now enter =NOT(ISNA(VLOOKUP($W2,A$2:A$4,1,FALSE))) in X2 (replace the 4 with the number of the last row that contains data), and drag/fill down to match Column W (i.e., one row for each unique value in your original data) and to the right to Column Z (i.e., the number of columns in your data).

                              table showing TRUE/FALSE for whether each value is in each column

This gives you a truth table corresponding to the second form of the desired result in the question (but with “TRUE” and “FALSE” instead of “Yes” and “No”).  For example,

  • X2 is TRUE because Column A contains “aaaaa”,
  • X3 is TRUE because Column A contains “bbbbb”,
  • Y2 is TRUE because Column B contains “aaaaa”,
  • Y3 is FALSE because Column B does not contain “bbbbb”, etc.

Delete column V, and fix the headings (in Row 1) at your leisure.  If you don’t want to keep Columns A-C in the spreadsheet, then copy Columns W-Z and paste values.


Some explanation on the formula: The formula I have presented above is for use in Column X, which corresponds to Column A.  Since I used $W2, this is an absolute reference to Column W and it will refer to cell Wn when the formula is dragged/filled to row n of any column.  By contrast, A$2:A$4 is an absolute reference to Rows 2 through 4, but a relative reference to Column A.  When the formula is dragged to Column Y, this reference will automatically change to B$2:B$4.  When the formula is dragged to Column Z, this reference will automatically change to C$2:C$4.

  • This looks great, I think we will try it. – Lenna Sep 26 '12 at 18:06

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