- Menu Command: Analysis: Peaks and Baseline: Peak Analyzer: Open Dialog
- Window Types: Workbook, Graph
This page is added to the wizard when Baseline Mode is set to Asymmetric Least Squares smoothing (ALS).
| Dialog Theme | See Peak Analyzer Themes. |
|---|
Specify parameters for Asymmetric Least Squares Smoothing (ALS) method.
| Asymmetric Factor [0-1] | Specify weight of points above the baseline in each iteration. For positive peaks it should be close to 0, and close to 1 for negative peaks. The asymmetric factor must be between 0 and 1. The smaller the asymmetric factor is, the less effect points above the baseline have on baseline in next iteration. The asymmetric factor should be chosen close to 0 for positive peaks, eg., 0.001, and close to 1 for positive peaks, eg.,0.99 |
|---|---|
| Threshold (%) | Specify the threshold to determine points above the baseline (for positive peaks) or below the baseline (for negative peaks). The threshold is defined by the ratio of a critical distance of point to baseline to that of peak to baseline. A point whose distance to baseline is greater than the threshold will be considered above the baseline (for positive peaks). And the threshold must be between 0 and 1 (not equal to 1).
The smaller the threshold is, the more points above the baseline (for positive peaks) will be excluded to determine the baseline in next iteration. |
| Smoothing Factor | Specify the smoothness of the baseline. The smoothing factor must be greater than 0, and the typical value is 2 and 9. The larger the smoothing factor is, the smoother the baseline will be. |
| Number of Iterations | Specify number of iterations. The typical value is 10. In each iteration, it will find a baseline, and determine which points will be considered as points above the baseline for next iteration. |