Replacement for Figure 1 in Clancy EA and Hogan N.  "Probability Density of the Surface Electromyogram and Its Relation to Amplitude Detectors," IEEE Transactions on Biomedical Engineering, Vol. 46, No. 6, pp. 730–739, 1999.

Fig. 1.  Normalized composite probability density estimates for Experiment One.  Experimental density (dark solid line) is the average of 660 recordings.  Error bars indicate one standard deviation above and below the average.  Data were recorded from biceps and triceps muscles during constant-force, constant-angle, nonfatiguing contractions.  Line marked with "+" indicates the Laplacian density and line marked with "o" indicates the Gaussian density.