This dialog is activated by selecting the Subtract -> Baseline command from the Analysis menu. With its help it is possible to create and subtract a baseline from your data curves.
By pressing the Create Baseline button the number of baseline anchor points specified using the Points box are generated automatically or manually and then connected with an interpolation curve or with a custom function. The automatically generated anchor points equally spaced.
There are three methods available for the creation of the anchor points of the baseline curve:
Curve data points are interpolated using one of the three available methods (Linear, Cubic and Non-rounded Akima).
The anchor points are calculated using a custom analystical function Y = f(x).
Finally if you already have the coordinates of the baseline anchor points you can use them by indicating the table column where the dataset is stored.
After the creation of the baseline you can modify the position of the anchor points by pressing the Modify button. You can set the new positions by simple drag-and-drop using the mouse pointer. Precise positioning of the anchor points can be achieved using the arrow keys (Left and Right arrows change the point to modify Up and Down arrow keys move vertically the point). It is also possible to use the numeric keypad which define a sort of compass rose:
Finally by pressing the Subtract button the baseline data is subtracted from your spectrum. This operation can be undone using the Undo Subtraction button.