Custom field Empower 2 to Calculate a %diff

[kagliostro]

Hi to everyone,
I am new to this forum and I would like to ask a question about a custom field calculation in Empower 2.
All I wanna do is to calculate a percertange between ten averaged amount values and the single values which contributes the averaged value. Matematically I mean:

a1 = 2.222
a2 = 2.225
a3 = 2.224
a4 = 2.226
a5 = 2.221
Average=2.2236

%1= a1/Averaged_Amount *100
%2= a2/Averaged_Amount *100

How can I setup a custom field in Empower 2 to do this operation? What formula shall I write in the custom field to obtain the percentage result for each injected sample?

Thanks a lot in advance for your help

[DR]

Empower does this automatically for standards, I think it's called Deviation. See if you can find that field and apply it to same labeled samples...

[kagliostro]

Thanks a lot for your answer, today I did several trials and it looks like that the %Difference is only for the standards.
The empower help says that to do my calculation I have to introduce an intersample custom field. However I do not know how to write the formula. I am struggling to find infos to how to build the formula string in Empower, if you could pass that it would be a real benefit for me.
In any case thanks a lot for your help

[shaun78]

Use sample labels from within Empower.

Give all samples a label that will be made the same with a single wild card. For example, SMPX will allow for 0-9 samples using X as a single wild card. You want to use the partial (re: single character) wildcard here (?) for the sample label. You would use SMP1, SMP2, SMP3 ... SMP9, as the labels in your actual sample set method.

Two custom fields:

SMP_Average: SMP?.%.%.AVE(Area)

SMP_Difference: (SAME.%.%.(Area)/SMP_Average)*100

Because of the use of summary functions in custom fields, you will need to have "summarize custom fields" as the last line in your sample set method.

[shaun78]

If that does not work, then try to use the same sample label for all the samples (SMP1, for example).

The custom fields then become:

SMP_Average: SMP1.%.%.AVE(Area)

SMP_Difference: (%.%.%.(Area)/SMP_Average)*100

[kagliostro]

If that does not work, then try to use the same sample label for all the samples (SMP1, for example).

The custom fields then become:

SMP_Average: SMP1.%.%.AVE(Area)

SMP_Difference: (%.%.%.(Area)/SMP_Average)*100

Thanks a lot I solved my problem with this. You were very kind guys to help me in this.