# Questions tagged [smoothing]

Smoothing methods in data analysis, like splines or kernel smoothers, also regression smoothers like lowess.

291 questions
Filter by
Sorted by
Tagged with
61 views

### Forcing smoothness of regression coefficients

I'm building regression models on spectral datasets: the predictors are the intensites of signal at the different frequencies. In this case the intensities at close frequency values are highly ...
32 views

### Smoothing time series with non-constant variance

I have a discrete time series $x(t)$ $t = \{0,\Delta t,2\Delta t\dots\}$ in which every point comes with a confidence value $c(t)$ arising from the measurements. You may think of is as the variance ...
68 views

86 views

### Should I do detrending or smoothing first?

Does it matter which one I perform first? If yes, why? Might be a simple question, yet I could not find an answer anywhere else.
63 views

### How does the penalized form of RSS (residual sum of squares) work?

In another word, how to reverse engineering the equation (5.9) by explain all the assumption and reasoning after the plus sign of (5.9) in Elements of Statistical Learning. Note: I had used the ...
18 views

### how to parameter the gamess function?

i want to run gampackage to calculate threshold and semi parametric model, especialy partialy linear model like : Y = V1 + V2 + V3 + f(V4) where: Y is factor and dichotomic varible; V1 is continuous ...
21 views

### What does alpha in smoothing stand for

I want to apply Gaussian smoothing to a dataset and came across the smth.gaussian function in R. That besides the numerical input data requires two parameters: ...
35 views

### How to generate mean curve of non-function?

I am currently working on curves generated in tensile tests of polymer specimens. Here, I try to generate a mean curve of five data sets generated at the same composition of the samples. Unfortunately,...
324 views

### Is there a name for a moving average when it is done not across time but some other variable?

The moving average is defined as A method of smoothing a time series to reduce the effects of random variation and reveal any underlying trend or seasonality. (Oxford Dictionary of Statistics, ed. ...
17 views

### Smoothing detected vehicle positions from camera given my own vehicle's location, velocity and acceleration

I have a dashcam which detects the position and estimated depth of other vehicles on the road relative to my own. Given my own vehicle's global co-ordinates, I can convert the detected vehicle's ...
89 views

### Detecting trend in panel data, smoothing techniques and outlier detection

I'm conducting an analysis on a Landsat scene to detect trends for change detection phenomena (forest disturbances) over a time series of 20 years. I identified on the image the pixels that are ...
37 views

92 views

### Retrieving time series from a smoothed periodogram

If I were to smooth a periodogram and then filter out low level frequencies, how can I derive the filtered time series? For example, in the case of a non-smoothed periodogram: https://folk.uib.no/...
224 views

### Natural spline term in GAM

Is it advisable to use natural regression spline basis? I learned that in R the supported smoothers in gam are the lo, ...
18 views

73 views

397 views

### Functional Data Analysis and Splines Regression

I'm new to Functional Data Analysis so my question will'be very simple for an expert in this topic. Operatively, when I fit a model like this, in R : model<- lm( y ~ bs( x, df = k, degree = l ) )...