# Boolean Custom Field

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edited October 2019
I want to create a boolean custom field which gives me a 1 when the EP s/n is equal or higher than 3. Also I would like to have a 1 in the custom field when the field "EP s/n" is empty (for example with group peaks).

This is the CF I've tried, but it does not give a 1 when the EP s/n field is empty:
GTE([EP s/n],3)IEQI([EP s/n],0)

Is the value for a blank field = 0?
Do I need to check the "all or nothing" option for this?

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Did you try ticking the Missing Peak and re processing?

A blank field will not return 0 unless you ask Empower to do this. Im not sure you need the square brackets around the EP s/n field, this is only used when you want to specify a certain peak, eg Caffeine[EP s/n] or CCompRef2[Ep s/n] etc.

So change the formula to GTE(ROUND(EP s/n,0),3)|EQ(REPLACE(EP s/n,0),0) tick the missing peak box and in the Use as Position (or Value) table for the position 1 put in the number 1 and in the position 0 (ie any values outside these conditions) put in whatever value or text you like.
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Thank you for your help, but I still don't get a value for the Total impurities (which is a group peak).

Ticking the missing peak box does not change the outcome.

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I'm confused, you didn't mention total impurities in your first post, what exactly are you looking for again with regards to the formula and what peaks/samples do you need it calculated for?
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I want all the peaks with S/N >= 3 to be used for calculation of impurities. I put in the GTE formula, which returns a 1 if it's bigger. Then I multiply this boolean value with the area to give the impurity response. I want this response to be used for the impurity calculations.

I get the right calculation for each individual impurity, but the total impurities are not calculated, since no S/N is assigned because it's a group peak...

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Can you use the report for this. ie make a table of all the values with S/N GTE 3 and add a SUM function at the end to get total? Are you using the Impurity tab in the processing method or do you just want a total area count for peaks with the S/N GTE 3?
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I used the SUM function as a result CF and that does what I want. Thanks!
Can I use another type of CF to make the sum visible during review?

What happens if I use the SUM as a result CF and make a report with "summary by all"? Does it make the sum of the three samples?
I would like to calculate the sum of the data for every sample and then make the average.

Thank you!
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Result CFs only give one answer per chromatogram so if you have 3 injections of unknown samples then each injection will give a different one for the Total Impurities using your Result CF. Summary by All is not linked to this, Summary by all simply reports all selected data together in contrast to an individual report which generates an individual report for each channel, result etc. If you want to include the Result CF in a peak table, you should use an All Peaks table and include SampleName as an identifier to track the sample. You can add a SUM to the end of this table to display the total impurities values over x number of samples run.

If you want to see a Result CF when reviewing raw data, open up the channels, apply your processing method/method set to the data and select the "Results" icon in review window (Its the Equals symbol) then halfway down this screen all the results connected to this injection are displayed so Result ID, Detector Noise etc, Result CFs are usually populated at the end of this table, and can be dragged to the front and preferences saved as required. But please note im not 100% sure if a result cf with a SUM incorporated into it will actually display in review mode- it may need to be processed using Summarize Custom Fields to generate the results in the result set. That's something you need to  check.