Fig. 1

This figure illustrates the weight function and smoothing corresponding to finite difference diffusion, with the trend smoothness parameter set to 80. Time is on the horizontal axis (in seconds) and the fluorescence intensity of the Fluo-4 emission is on the vertical axis (arbitrary units). For the original Ca²⁺ recording (in black), the smoothing is given by the dotted red curve. To visualize the smoothing calculation, at the dashed blue line, the smoothed value is computed by weighting the values of the original profile proportionally with the weight function shaded in light blue. Notice that this weight function is approximately Gaussian