Empower Custom Fields Help

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Hello!

So my team recently imported some cIEF data using a PA800 plus system. There are three pI markers in each injection that we would like to use to generate a slope and Y-intercept from the pI markers. I attempted to make a long, nasty custom field for this and there's one portion that I can't get to work.

We named the peaks PI_1, PI_2, and PI_3 in the processing method to designate the pI marker peaks. Here's the part of my custom field that I can't get to work:

(PI_1[Migration Time]-PI_Avg_MT)+(PI_2[Migration Time]-PI_Avg_MT)+(PI_3[Migration Time]-PI_Avg)MT)

The custom field for PI_Avg_MT is (PI_1[Migration Time]+PI_2[Migration Time]+PI_3[Migration Time])/3 and this CF works as intended.

Currently, we have custom fields working to utilize two of the three pI markers (following how Maurice cIEF data is used in Empower to utilize the pI markers via Waters Support). We were just trying to find a way to use all three pIs without success.

Let me know if I can provide any more information!
Hi, I recreated this custom field and got it to work on some test data. The issue is the naming of the custom fields and the order they calculate. Instead of calling the first CF PI_Avr_MT, I would delete that CF, create it again and call it Avr_PI_MT. Custom fields are calculated in alphabetical order and its possible that your second CF was named with a lower letter than P (PI_Avr_MT), and since this CF references the PI_Avr_MT, there would have been no value for that yet and so your second CF crashed out and gave no result. Custom fields with names beginning with A are calculated before B, B is calculated before C...etc. This is the case when you make a formula depending on a CF already having a value.

I would do two things to your second CF. Firstly, add an ABS around the brackets in case you get a minus value, and secondly, name it with a letter higher than A, for example, Final_PI. So your formula becomes:

ABS(PI_1[Migration Time]-Avr_PI_MT)+ABS(PI_2[Migration Time]-Avr_PI_MT)+ABS(PI_3[Migration Time]-Avr_PI_MT)

This will give you the correct result when you open a channel of data and process.
Hi there, we're also trying something similar with 5 standards using cIEF data. Did the advice help solve your problems? Would you be able to share the formulas you used please?
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