3.18 FAQ-243 Why my fit did not converge when I have exponential functions?

Last Update: 2/4/2015

For an exponential function exp(x), Origin will return missing value when the independent variable x is greater than 665.

In order to get the fit converge, you need to redefine the equations to avoid the x variable value of the exp(x) function from greater than 665.

For example:

1) You can take natural logarithm for both sides of equation.

2) If your function has expression in the form of exp(x1)*exp(-x2), you can transform it as exp(x1-x2)

Keywords:curve fitting, fitting error, exponential function