Shared Backgrounds Display

[Heather Lowers]

Question about the shared backgrounds...

For several of my elements, either the peak position or peak position and high or low background are out of the chart area.  I click the zoon multipoint button which may bring the peak position in to the chart view but not a single high or low background point. I understand there may be no shared points on that side but I'd like to see at least one point on the opposite side of the peak.

[Probeman]

Question about the shared backgrounds...

For several of my elements, either the peak position or peak position and high or low background are out of the chart area.  I click the zoon multipoint button which may bring the peak position in to the chart view but not a single high or low background point. I understand there may be no shared points on that side but I'd like to see at least one point on the opposite side of the peak.

Hi Heather,
The Display MPB window displays all plotted MPB backgrounds.  If there aren't any MPB points on one side of your peak, it won't display them.  It is a feature that one doesn't have to have any MPB points on either side of the peak as requested by Julien Allaz (just as it the case for normal off-peaks when they are "same side" off-peaks). 

If one element doesn't have any "shared" bgds on one side of the peak, you can turn of the shared bgds feature in the Elements/Cations dialog for that element.  Did I miss your point?
john

[Heather Lowers]

I think I get your point but it would be nice to see the one point on "the other side" of the peak that may not be a shared or multipoint position so I can see how the background fits under the peak and on to the other side.

[Probeman]

I think I get your point but it would be nice to see the one point on "the other side" of the peak that may not be a shared or multipoint position so I can see how the background fits under the peak and on to the other side.

What you see is what it found for "bgd sharing". 

But I noticed in your MDB file that you had a bunch of elements disabled for quant/acquisition. The bgd sharing feature will skip those elements that are marked "disabled".  If some of them were acquired but just disabled for quant, then you could enable them and they will then also get plotted.

Also, the normal off-peak bgds for the emitted element (the one you are seeing plotted), should always (at least) have a background on each side of the on-peak position, unless you specified both off-peaks to be on the same side of the emission line.
john

[Heather Lowers]

I guess that is what I am saying...for elements that have been acquired and have normal off-peaks on each side of the on-peak position, I want to see that background position plotted whether it is shared or not.  Is that possible?

As an example, I attached the plots for Si and Al.  There are no points plotted on the low side of the Si peak so I'm a little uncertain of the slope of the background under the peak.  However, when I look at the Al plot, the low background position for Si is plotted.  I want to be able to see that low background position for Si in the Si window as well.

Ain't this forum thing fun

[Probeman]

I guess that is what I am saying...for elements that have been acquired and have normal off-peaks on each side of the on-peak position, I want to see that background position plotted whether it is shared or not.  Is that possible?

As an example, I attached the plots for Si and Al.  There are no points plotted on the low side of the Si peak so I'm a little uncertain of the slope of the background under the peak.  However, when I look at the Al plot, the low background position for Si is plotted.  I want to be able to see that low background position for Si in the Si window as well.

Hi Heather,
I see.  You have iterate lo set to zero for Si.  Change that to one or higher to see backgrounds on that side (if they are present and can be shared). 

Also make sure you don't have the Check For Same PHA Settings checked as seen here:

Ain't this forum thing fun

Glad you like it!

[Heather Lowers]

I do not have iterate lo set to zero, the software does.  There are no options but zero from the pull down list.  Also, Check for Same PHA is unchecked.

[Probeman]

I do not have iterate lo set to zero, the software does.  There are no options but zero from the pull down list.  Also, Check for Same PHA is unchecked.

Hi Heather,
OK, then it means that it could not find another MPB on that side of the peak.  As I said, it should find whatever is available.  I will look to see if there is anything I missed code-wise but is that the only anomaly you see in this run?
john

[Heather Lowers]

Don't know what you mean by only but in addition to Si this happens for Ca, Y, Pr, U, As, Ho, Yb, Lu, and La.  Nothing stands out to me as to why these elements and not others.

[John Donovan]

Don't know what you mean by only but in addition to Si this happens for Ca, Y, Pr, U, As, Ho, Yb, Lu, and La.  Nothing stands out to me as to why these elements and not others.

Good catch!   The "shared" bgd code was missing some multi-point backgrounds in its search!



The code is now fixed and will be ready to download in the morning.
john

Edit by John: I'm curious though- I haven't played too much with "shared" bgds and so I wonder if the above exponential fit gives you a negative or positive net intensity result (assuming no Si present).  I ask because although we assume that an exponential fit is sufficient for most background fit situations, over a very wide spectrometer range, as we see here, a "hyper-exponential" fit may be necessary.

[Heather Lowers]

Is it possible to add multiple samples to the shared background selection?  Right now each unknown is done separately.  I'd like to select multiple unknown samples from a run to do a batch shared backgrounds selection for elements. 

[Probeman]

Is it possible to add multiple samples to the shared background selection?  Right now each unknown is done separately.  I'd like to select multiple unknown samples from a run to do a batch shared backgrounds selection for elements.

If you select multiple sample it should find or remove "shared bgds" for all selected samples. Am I missing something?
john

[Heather Lowers]

Once in the Display MultiPointBackgroundIntensityData window, I'd like to select mulitple unknown samples that are listed. 

How do I turn off the connecting lines when I check the box for "Plot All Data Lines In Sample For The Currently Selected Element" or uncheck the "Display Fit Parameters" box?  Way distracting!

[John Donovan]

Once in the Display MultiPointBackgroundIntensityData window, I'd like to select mulitple unknown samples that are listed. 

How do I turn off the connecting lines when I check the box for "Plot All Data Lines In Sample For The Currently Selected Element" or uncheck the "Display Fit Parameters" box?  Way distracting!

Easy peasy!





john

[Heather Lowers]

Lemon squeezy!  Thanks