Rainbow (tm) allows you to find the best Spectral Estimation Method for your data's Power Spectral Density (PSD) plot. A menu of 10+ spectral estimators from Steve Kay's textbook, Modern Spectral Estimation, 1988, is available to choose from. The results differ dramatically from one estimator to another. Plus, varying input parameter and/or number of points may provide discrepancies. See how zero padding effects your results.

Estimation methods in Rainbow include Autocorrelation, Covariance, Prony, Akaike, Burg, Recursive Maximum Likelihood Estimation, Modified Yule-Walker Equations and others.

This picture/plot shows a PSD plot for one of the thirteen methods available to choose from. The methods can vary dramatically in their results. Try several before choosing which estimation is best to represent your PSD.

Manufacturing companies take note! Some estimators can detect signals 50 to 100 dB from main signal. See documented example! The unwritten rule of '30 dB is okay' (i.e. hidden) is no longer true.

See how zero padding effects ones results. Ability to change array sizes on the fly and thus show zero padding effect is/was main reason for writing this software.

Have sinusoidal data? Find your data's math model.

Do you have some data that needs a sinusoidal math model? Solution for a sine series to fit your data can be a hard problem for a solver. Try finding your data's main frequencies and enter them into our CurvFit program as initial starting values. Rainbow combined with CurvFit may provide an excellent math model for sinusoidal data.

Before you buy!

Try Rainbow -before- buying it. Rainbow may be freely downloaded by clicking here . Install Rainbow and be sure it works okay for you before buying. Rainbow program is around 2 mbytes in size, and requires a Windows 95 or newer OS. Rainbow is shareware. Thus, you can share it with your friends.

Other math software (e.g. CurvFit, ODEcalc, etc.) are available here at digitalCalculus.com