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Automatic Integration and Automatic Scale Fragmentation of 1-D Spectra

Choose View > Integrate now. On the Mac this command appears when you hold down the alt key. It performs automatic integration (any pre-existing integral region remains unaffected) by applying a chain of filters. Each filter can reduce the number of integrals. The very first filters are hard-coded into the program and you can't do anything about them. The last three filters are user-adjustable.
Choose View > Auto-Integrate (without the alt key). Now the three filters are exposed and you can verify, in real time, what happens when you modulate them. The filters are applied in succession and should be touched in the same order, from top to bottom. You can use the usual navigation keys to control what happens in different parts of the spectrum. On Windows, you need to click on the word “interact” to enable navigation.

what each filter does:

Step 1

minimal width (points)

If an integral region contains less points than this value, it is filtered out. When the value is 1 point, this filter has no effect.

Step 2

merging distance (ppm)

iNMR adds more space on both sides of each integral. If two integrals are very near to each other, they will be fused. When the value of this filter is 0 ppm, it has no effect.

Step 3

maximum allowed ratio

This value corresponds to the normalized intensity of the highest integral. All integrals whose normalized intensity is less than one are eliminated. The highest the value, the more integrals are created. When you set this value = 5, for example, the weak integrals (less than 20% of the tallest one) are eliminated. You can set values higher than 200 when you run this command from the console, yet you will normally prefer smaller values. Negative integrals are never created by the automatic routine.

The same regions, instead of being integrated, can be the target of a multiple expansions (what you normally achieve with the cutter tool). You have a switch at the bottom of the dialog to choose between integration and cutting.

Related Topics

Tabulating the Integrals of a Series


Web Tutorial

Automatic Integration