Exponential Fit Coefficients (Not in Base Package)

Finds the set of exponential coefficients amplitude and damping, which describe the exponential curve that best represents the input data set. This VI is a subVI of the Exponential Fit VI. Details

Y Values must have the same sign and must contain at least two points. That is, >0 for i=0, 1,...n – 1 or <0 for i=0, 1,...n – 1, n 2, where Y represents the input sequence Y Values and n is the number of data points. If the signs are inconsistent or there are less than two sample points, the VI sets Best Exponential Fit to an empty array, sets amplitude, damping, and mse to NaN, and returns an error via the Exponential Fit Coefficients VI. Refer to Exponential Fit Coefficients for more information about this VI.
X Values must contain at least two points. n is greater than or equal to 2, where n is the number of data points.
amplitude is the amplitude of Best Exponential Fit.
damping is the damping constant of Best Exponential Fit.
error returns any error or warning condition from the VI.

Exponential Fit Coefficients Details

The general form of the exponential fit is given by

where F is the sequence representing the best fitted values, X represents the input sequence X Values, a is the amplitude, and is the damping constant.

Note  This VI performs an exponential fit even when the elements of Y Values are negative. The VI performs the fit under the assumption that the amplitude coefficient is also negative and returns a negative amplitude. Y Values cannot be a mixture of positive and negative elements.