wavelet

问题 I am trying to implement a wavelet transform in C and I have never done it before. I have read some about Wavelets, and understand the 'growing subspaces' idea, and how Mallat's one sided filter bank is essentially the same idea. However, I am stuck on how to actually implement Mallat's fast wavelet transform. This is what I understand so far: The high pass filter, h(t), gives you the detail coefficients. For a given scale j, it is a reflected, dilated, and normed version of the mother

问题 I am trying to implement a wavelet transform in C and I have never done it before. I have read some about Wavelets, and understand the 'growing subspaces' idea, and how Mallat's one sided filter bank is essentially the same idea. However, I am stuck on how to actually implement Mallat's fast wavelet transform. This is what I understand so far: The high pass filter, h(t), gives you the detail coefficients. For a given scale j, it is a reflected, dilated, and normed version of the mother

问题 I am trying to implement a wavelet transform in C and I have never done it before. I have read some about Wavelets, and understand the 'growing subspaces' idea, and how Mallat's one sided filter bank is essentially the same idea. However, I am stuck on how to actually implement Mallat's fast wavelet transform. This is what I understand so far: The high pass filter, h(t), gives you the detail coefficients. For a given scale j, it is a reflected, dilated, and normed version of the mother

问题 I have a code that I am working on for hourly dataset and want to display a proper wavelet plot but I am having trouble adjusting it to my liking. I want to change the x-, y- axis and put up a color bar. I have successfully changed the x-axis, however, that is only when color bar is not activated. If it is, then I cannot change the x-axis. In addition, I haven't found a successful way to change the y-axis to have more values in between then what is automatically generated. Thank you in

问题 I have a code that I am working on for hourly dataset and want to display a proper wavelet plot but I am having trouble adjusting it to my liking. I want to change the x-, y- axis and put up a color bar. I have successfully changed the x-axis, however, that is only when color bar is not activated. If it is, then I cannot change the x-axis. In addition, I haven't found a successful way to change the y-axis to have more values in between then what is automatically generated. Thank you in

问题 I have a code that I am working on for hourly dataset and want to display a proper wavelet plot but I am having trouble adjusting it to my liking. I want to change the x-, y- axis and put up a color bar. I have successfully changed the x-axis, however, that is only when color bar is not activated. If it is, then I cannot change the x-axis. In addition, I haven't found a successful way to change the y-axis to have more values in between then what is automatically generated. Thank you in

问题 I would like to use rollapply or rollapplyr to apply the modwt function to my time series data. I'm familiar with how rollapply/r works but I need some help setting up the output so that I can correctly store my results when using rollapply. The modwt function in the waveslim package takes a time series and decomposes it into J levels, for my particular problem J = 4 which means I will have 4 sets of coefficients from my single time series stored in a list of 5. Of this list I am only

问题 Closed. This question is off-topic. It is not currently accepting answers. Want to improve this question? Update the question so it's on-topic for Stack Overflow. Closed 4 years ago . Does anyone know of a good C/C++ wavelet library for signal processing? The signal is float or double valued, not int valued. 回答1: Without more information or clarification of what you mean by good (Good for what ?), it is difficult to make any recommendation. Some C/C++ Wavelet libraries are listed below.

问题 I have 3 time series which I can apply the wavelet transform to using a rolling window. The rolling window takes a single time series of length 200 and applies the waveslim::modwt function to it over the first 30 samples. This outputs 5 lists of which I am only interested in (d1,d2,d3,d4) and these each have a length of 30. A simple example can be found here: library(waveslim) J <- 4 #no. of levels in decomposition data(ar1) ar1.modwt <- modwt(ar1, "la8", J) @G. Grothendieck has kindly

问题 I am new to matlab and signal processing. I have wrote the below posted code. what i could not understand is, the time soecification section at the beginning of the code. I do not why do we need sampling when specifying an interval or time duration, i think it suffice to specify something like the following : t = (0: 0.2: 1.0) for an example, why do i need some thing like sampling to plot such as stationary signal. another question is, this code gives me an error saying paranthesis imbalance