Note: This page has been translated by MathWorks. Please click here

To view all translated materials including this page, select Japan from the country navigator on the bottom of this page.

To view all translated materials including this page, select Japan from the country navigator on the bottom of this page.

Wavelet synchrosqueezed transform

`sst = wsst(x)`

```
[sst,f]
= wsst(x)
```

`[___] = wsst(x,fs)`

`[___] = wsst(x,ts)`

`[___] = wsst(___,wav)`

`wsst(___)`

`[___] = wsst(___,Name,Value)`

returns
the wavelet synchrosqueezed transform, `sst`

= wsst(`x`

)`sst`

, which
you use to examine data in the time-frequency plane. The synchrosqueezed
transform has reduced energy smearing when compared to the continuous
wavelet transform. The input, `x`

, must be a 1-D
real-valued signal with at least four samples. `wsst`

computes
the synchrosqueezed transform using the analytic Morlet wavelet.

`[___] = wsst(`

uses
a `x`

,`ts`

)`duration`

`ts`

with
a positive, scalar input, as the sampling interval. The duration can
be in years, days, hours, minutes, or seconds. If you specify `ts`

and
the `f`

output, `wsst`

returns
the frequencies in `f`

in cycles per unit time,
where the time unit is derived from specified duration.

`[___] = wsst(___,`

uses
the analytic wavelet specified by `wav`

)`wav`

to compute
the synchrosqueezed transform. Valid values are `'amor'`

and `'bump'`

,
which specify the analytic Morlet and bump wavelet, respectively.

`wsst(___)`

with no output arguments
plots the synchrosqueezed transform as a function of time and frequency.
If you do not specify a sampling frequency, `fs`

,
or interval, `ts`

, the synchrosqueezed transform
is plotted in cycles per sample. If you specify a sampling frequency,
the synchrosqueezed transform is plotted in Hz. If you specify a sampling
interval using a duration , the plot is in cycles per unit time. The
time units are derived from the duration.

`[___] = wsst(___,`

returns
the synchrosqueezed transform with additional options specified by
one or more `Name,Value`

)`Name,Value`

pair arguments.

[1] I. Daubechies, I., J. Lu, and H. T. Wu. "Synchrosqueezed
Wavelet Transforms: an Empricial Mode Decomposition-like Tool", *Applied
and Computational Harmonic Analysis*. Vol. 30(2), pp.
243–261.

[2] Thakur, G., E. Brevdo, N. S. Fučkar, and H. T.
Wu. "The Synchrosqueezing algorithm for time-varying spectral analysis:
robustness properties and new paleoclimate applications." *Signal
Processing*. Vol. 93, pp. 1079–1094.

Was this topic helpful?