Keywords - Function groups - @ A B C D E F G H I J K L M N O P Q R S T U V W X Y Z

Library: wavelet

fwttin Generates the translation invariant estimate of x with automatic hardthresholding. It is well-known that nonlinear wavelet estimators are not translation-invariant: if we shift the underlying data set by a small amount, apply nonlinear thresholding and shift the estimator back, then we usually obtain an estimator different from the estimator without the shifting and backshifting operation. To get rid of this, we average over several estimators obtained by shifting, nonlinear thresholding and backshifting.
stein Stein computes the optimal threshold for a vector of data plus noise so that the mean squared error is minimized. Stein uses Stein's unbiased risk estimator for the risk. The macro sure uses stein to threshold the father and mother wavelet coefficients.
sure Sure denoises wavelet coefficients so that the the mean squared error is minimized. MSE is estimated by Stein's unbiased risk estimator based on the variance of the coefficients. Sure computes the optimal threshold for the father wavelets and each level of mother wavelets. The input arrays can be obtained by the function 'fwt'.
sure2d Sure denoises wavelet coefficients. If the stein procedure is chosen, the mean squared error is minimized. MSE is estimated by Stein's unbiased risk estimator based on the variance of the coefficients. Sure computes then the optimal threshold for the father wavelets and each level of mother wavelets. If soft or hard thresholding is chosen, only the mother wavelet coefficients will be denoised.
waveletmain Generates global objects which contain the wavelet coefficients
wavelettest tests all noninteractive macros of wavelet.lib
wavesmo Generates smoothed mother wavelet coeffients and the resulting estimate. x contains the vector of data and l gives the number of father wavelet coefficient (power of 2). h is the vector of wavelet basis coeffients (automatically generated by calling he library wavelet. s contains the threshold values, either one for all mother wavelet coefficients or for each level. Set tt=0 for hard thresholding and tt=1 for soft thresholding.

Keywords - Function groups - @ A B C D E F G H I J K L M N O P Q R S T U V W X Y Z

(C) MD*TECH Method and Data Technologies, 28.6.1999