Figure 1
From: Baseline Correction for NMR Spectroscopic Metabolomics Data Analysis
LOWESS smoothing for variances estimation. Variances versus mean intensities sampled bins of 1D NMR metabolomics spectra. The bin size was set to 32 data points, corresponding to 0.012 ppm in chemical shift. The fitted LOWESS regression curve was plotted in red, and the flat region of the LOWESS curve represents the estimated noise variance.