Empower 2 Custom Field ?

ChrisY

<p>I am having an issue with custom fields.  I want to get the average of another custom field that I created.</p><p>I have several samples labelled (U01, U02, U03....U20).  I want the average of a custom field for the those 20 samples (I'll use CUSTOM_X as the field name).</p><p>The sample set is set to don't process for everything and there are Quantitate and Summarize Custom Fields rows at the end that are set to normal.</p><p>I need to see this average value (I'll call it AVG_CUSTOM_X) for each sample as I need to use this value in another custom field.</p><p></p><p>Right now I can't get the average to diplay for each sample only for the last one.  I'll show an example of what is happening below.</p><p>(Example values for CUSTOM_X would be 10, 20, 30, 40, 50).</p><p></p><p>For sample 1 AVG_CUSTOM_X is showing as 10</p><p>For sample 2 AVG_CUSTOM_X is showing as 15 (average of 1 and 2)</p><p>For sample 3 AVG_CUSTOM_X is showing as 20 (average of 1, 2, and 3)</p><p>For sample 4 AVG_CUSTOM_X is sohwing as 25 (average of 1, 2, 3, and 4)</p><p></p><p>It keeps doing this until the last sample which shows correctly.  In the example above it would show AVG_CUSTOM_X = 30.</p><p></p><p>I don't understand why it is iterating through the average rather than showing me the overall average for each sample.  I have a ticket open with Waters and they are looking at this as well but they haven't figured it</p><p>out in the last couple of days so I am posting here in case someone has seen this before. </p><p></p><p>Thanks!</p>

Jonathan

Hi Chris -

What can you share about CUSTOM_X?  Is it an intersample field, or possibly a result field?  If the formula works for something like Area it should work for other calcs - it looks as if all of the CUSTOM_X results haven't generated at the time the summary function tries to execute.

ShaunWat78

Empower is using an iterative average because that is the way in which Empower works depending upon how you have your custom field setup.

Speaking of which... how do you have it setup?

My suggestion: for your 20 samples, use the same label for all 20 samples, say SMP20. You then use: SAME.%.%.AVE(Area)

Edit:

The suggestions of U%.%.%.AVE(Area) do not work because you can not fully wildcard a sample label in this manner. Alternatives would be U??.%.%.AVE(Area), but this binds you to having to use two characters for all sample labels. Additionally, if you test over 20 samples (say you want averages of two lots run at once), then the suggested mechanism falls apart because there is no way to distinguish the difference between lots. However, with SAME.%.%.AVE(Area), you are able to run as many lots as you wish and split the n=average into as many samples as you wish.

ChrisY

Thanks for your reply but you aren't understanding the problem.  U%.%.%.AVE(Area) works fine.  I can get that to work every time so I know Empower can do this.

The issue only occurs when you try to do an average of a field that isn't built-in (i.e. another custom field).  I think I am close to figuring this out with Waters so I don't need any other replies.

Thanks for everyone that tried to help.

ShaunWat78

My response applies to averages of other custom fields as well.

I hope Waters is able to get this sorted for you.

EParker

Hello. I believe this has to do with whether your injections are on one line on the sample set, or if they are on three separate lines. For example, you may encounter this problem if U1, U2, and U3 are on separate lines of the sample set, each with their unique label starting with U. However, if you have all 3 injections on one line, so they are all labeled the same (U1) then I do not believe you will have this problem.

If this doesn't fix the problem, then you can use filtering and display settings in the report method to ensure you are only showing the final average value. Hope this helps!

ChrisY

I had some complicated custom fields that had nested calculations in them.  One example was using an average of the samples to calculate another value.  So I had one custom field embeded in another.

If you remove the embedding it will work.

Example:

Custom field 1 (AVG_WEIGHT): U%.%.SAME.AVE(WEIGHT)

Custom field 2: (WEIGHT/AVG_WEIGHT)*X_VALUE

Custom field 3: Previously it was U%.%.SAME.AVE(Custom field 2).  This wasn't working.  I changed this to U%.%.SAME.AVE(WEIGHT/U.%.%.SAME.AVE(WEIGHT)*X_VALUE).  This works.

You basially have to break up the nesting and specifically list out the values.  This usually only applies to nested averages and % RSDs.

I am closing this question and marking it as answered as I don't need any other replies.

Thanks,

Chris