Mathematica can be used to calculate variables for the fitter "on the fly" by entering Mathematica expressions into the appropriate fields in the Fit Setup screen. Here we give a brief overview of some of the more common Mathematica expressions. We assume that the dataset has two variables named voltage and temp.
Name | Symbol | Example |
---|---|---|
Plus | + | voltage + temp |
Minus | - | voltage - temp |
Times | * | voltage * temp |
Divide | / | voltage / temp |
Power | ^, Power | voltage^2 or Power[voltage,2] |
Square root | Sqrt | Sqrt[temp] or temp^0.5 |
In the power and square root examples above, we see an example of three general principles of Mathematica:
What | Examples |
---|---|
exponential function, etemp | Exp[temp] |
natural logarithm, ln(temp) | Log[temp] |
logarithm to base b, logb(temp) | Log[b, temp] |
trigonometric functions (arguments in radians) | Sin[temp], Cos[temp], Tan[temp], Csc[temp], Sec[temp], Cot[temp] |
sine of "theta" when theta is in degrees | Sin[theta Degree] |
inverse trigonometric function, returning results in radians | ArcSin[temp], ArcCos[temp], ArcTan[temp], ArcCsc[temp], ArcSec[temp], ArcCot[temp] |
inverse sine of temp in degrees | ArcSin[temp] / Degree |
argument of temp + i*voltage where i is the square root of -1. | ArcTan[temp, voltage] |
hyperbolic functions | Sinh[temp], Cosh[temp], Tanh[temp], Csch[temp], Sech[temp], Coth[temp] |
inverse hyperbolic functions | ArcSinh[temp], ArcCosh[temp], ArcTanh[temp], ArcCsch[temp], ArcSech[temp], ArcCoth[temp] |
What | Example |
---|---|
A pseudo-random number between 0 and 1. | Random[] |
The square root of temp squared plus voltage squared. (This is not a Mathematica built-in, but is part of the Experimental Data Analyst package which is the "engine room" for the fitter.) | Quadrature[temp, voltage] |
This document was written by David Harrison, October 1999.