Remove duplicate rows in table (2024)

T = 11x4 table

Test col2 col3 col4 _____ _______ ________ ____ {'A'} 0.81472 0.14189 0 {'A'} 0.90579 0.42176 0.25 {'A'} 0.91338 0.79221 0.5 {'B'} 0.09754 0.65574 0 {'B'} 0.2785 0.035712 0.33 {'B'} 0.54688 0.84913 0.25 {'B'} 0.95751 0.93399 0.5 {'C'} 0.15761 0.75774 0 {'C'} 0.97059 0.74313 0.25 {'C'} 0.48538 0.65548 0.33 {'C'} 0.80028 0.17119 0.5

Hi Adam,

Thank you. I adapted this to my dataset and it seems to erase any row with 0.25 or 0.5. Looking through values listed in rowNum1 and 2, both rows in T that match the values 0.25 and 0.5 seem to be identified and are listed.

@DavidL88 My original solution removed the first row that contains .25 or .50 in col4 for each test even if there were not duplicates!

I've updated the answer fix that.

Now the solution only removes the rows if the .25 or .50 is a duplicate within each test.

Hi Adam

The effect as you demonstrate is what I'm looking for. I'm not sure why I got a different result. There is a duplicate of all 0.25 and 0.5s. I copy a sample of the table below before running this code. The 0.25 values for this section are in rows 39 and 40 of the table T.

This is the same section after running the code. In rowNum1 I can see both 39 and 40 listed.

This the exact code I ran on my table T. T3 is the last column and T4 is the first column.

First, please see my previous comment which I may have added while you were typing your response (I updated my solution).

Second, those trailing 0s are suspicious. Are you sure they are duplicates? For example,

If floating point representation is causing problems like this, you'll need to modify these two lines of my solution

Thanks. I ran that second script (adapted below). It didn't make any change to the table. The duplicate rows remained after running it this time. For rowNum1 and 2 the same vales are there (both are listed as 648x1 cell same as before with first script (with 39 and 40, the first set of duplicates, listed there too).

It shouldn't be a floating point as those numbers represent exact time-stamps. I double-checked and confirmed this on one duplicate.

> For rowNum1 and 2 the same vales are there

Impossible. rowNum1 values are based on T.T3==.25; rowNum2 values are based on T.T3==.50; It would therefore be impossible to have the same values in both variables unless the result is an empty array (no matches). Or maybe you meant that they have the same values as the previous version which would only happen if all tests had duplicates for .25 and .50.

> both are listed as 648x1 cell

It's expected that they are cell arrays with the same size.

> It shouldn't be a floating point as those numbers represent exact time-stamps

They aren't integers so it's not debatable whether they are represented by floating point or not. The question is whether their floating point representation is causing a problem with the equality tests. It doesn't matter that T.T3(39) equals T.T3(40). What matters is if those values equal 0.25 or 0.50, exactly.

Example:

I wonder if you're using long format which would also explain the trailing 0s.

Could you attach a mat file containing the table?

Just tried

Given that rowNum1 and 2 extracted these cells they should be equal to .25 and .5 exactly?

I sorted rowNum1 and got back this. Should it not be 39, 246, 453, etc?

rmRows is coming back as []

Can I email you the table rather than uploading it here?

The mathwork contact button does not support uploads.

You could upload it and remove it after I confirm that I received it.

Or you could upload it to a cloud service (e.g. Dropbox), send the link, and then remove it from the cloud service.

Or you could create a very similar table with dummy-data and make sure that it has the same problem as your table.

Hi Adam,

I figured it out. Sorry my mistake. If you look at the first example you'll see that in the first column of the duplicate rows the names are slight different (where the ms times are). I split this column after the second ms and re-ran your code, using the second new column as the test idenifier, so that the two rows are now identified as the same test. It worked perfectly and removed all the duplicate rows. Thanks for your help!

Ahh.... dpb actually pointed that out in a comment 19 hrs ago :)

Hi Adam,

Is there a way to adapt this code to remove any unique test that does not have a value <0.05 in col3? So if none of the cells below in col3 for the 'A' test have a value that is <0.05 then remove all rows for 'A'?

Yep, change "T.col4==0.25" to T.col4<0.05 and then test for empty cells using cellfun('isempty,___). It will return a logical column vector indicating which test groups do not contain any col4 values less than 0.05.

Thank you. I tried this.

I assume this is the right structure. rowNum3 finds those Tests with a value < 0.05 in T2. rowNums4 identifies those that came back negative and I can use this vector to remove those rows.

I'm getting the below message. I thought this might be due to the dimensions being different in that the previous code expected two matches/duplicates but this code is open to a variable number of matches? I tried removing ", 2" after <0.05 in the first line but same response.

You were close...

idx below returns a logical vector the same size as testNames indicating which test-names are flagged. Then you have to identify which rows of the table have those test names.

This worked thanks!