BSL PRO Software Guide - Biopac

Acquisition Functions 105Calculation Preset: MathThe Math Calculation performs standard arithmetic calculations using two waveforms or one waveform and aconstant.SourceTo use a summed waveform as an input for another Math Calculation channel, select thecalculation channel as a Source. The calculation channel used as a Source must have alower channel number than the Math calculation channel.OperandK (constant)ScalingUse the pull-down operand menu to select a math function.Operand Result+ Addition- Subtraction* Multiplication/ Division^ PowerEnter a value to be used as the constant for the calculation.As an alternative to creating an additional Calculation channel for dividing the summedwaveform, you can use the Scaling function to perform the same task. To do this, clickScaling… button and then set the Scale values for the summed waveform equal to +5 and-5 (to correspond to Input Volts values of +10 and -10 respectively). This will effectivelyplot the sum of channels A1 and A2 as the arithmetic mean of the two waveforms.See also…For additional libraries of online calculation options, consult the sections on Function Calculation and the onlineExpression Calculation. These types of calculation channels can be used to perform more complex operations onwaveforms. Although calculation channels can be “chained” together to form complex calculations (wherein theoutput from one serves as the input for another), a separate channel must be used for each function. Additionally,chaining more than three or four channels together can require considerable system resources.For complex calculations (such as squaring a waveform then adding it to the average of two other waveforms) theExpression calculation is a more efficient solution (see page 6109). Also, all of the features available online in theMath Calculation channels can be computed after an acquisition using the Waveform Math option (see page 6220),which will eliminate the problem of system overload.