One-Dimensional

  • Line
  • Polynomial
  • Gaussian peak
  • Lorentzian peak
  • Exponential with X offset constant
  • Double Exponential with X offset constant
  • Exponential
  • Double Exponential
  • Sin
  • Hill Equation
  • Sigmoid
  • Power
  • Lognormal

Two-Dimensional

  • Gaussian
  • Polynomial

All built-in nonlinear fit functions feature automatic initial guess generation.

Override automatic initial guesses with your own.

Hold any fit coefficient. For instance, hold constant term in line fit to fit a line through the origin or any other y-intercept.

Built-in Fit Function Illustrations

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Igor Pro 8

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Igor XOP Toolkit

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Igor NIDAQ Tools MX

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