BSL PRO Software Guide - Biopac

106 Part CCalculation Preset: FunctionThe Function calculation can be used to perform a variety of mathematical functions using two waveforms or awaveform and a constant. Function calculation channels compute new waveforms in a manner similar to the Mathcalculation, but provide access to higher order functions. Like Math calculations, Function calculations can bechained together to produce complex functions (such as taking the absolute value of a waveform on one channel andcalculating the square root of the transformed waveform on another channel).Function OperationAbsReturns the absolute value of each data pointATanComputes the arc tangent of each data pointExpTakes the e x power of each data pointLimitLimits or “clips” data values that fall outside specified boundariesLnComputes the base e logarithm for each data pointLogReturns the base 10 logarithm of each valueNoiseCreates a channel of random noise with a range of ± 1 VoltSinCalculates the sine (in radians) of each data pointSqrtTakes the square root of each data point.Threshold Converts above an upper threshold to +1 while converting data below a lowerthreshold to -1. If the initial data lies between the upper threshold (UT) and thelower threshold (LT), the output is undefined.Note: Off-line Threshold values are +1 and 0 (see page 6207).Top: Signal + NoiseMiddle: P-P Noise > UT-LTBottom: P-P Noise < UT-LTSee also…For post-acquisition operations, these functions are available under the Transform menu (page 6199). Functioncalculations can be chained together to produce complex calculations, but it is more efficient to program complexfunctions using the Expression calculation; many of these functions are also found in the online Expressioncalculation (see page 6109).Visit the online support center at www.biopac.com