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Questions tagged [loess]

Local regression - a form of non-parametric regression.

Local regression - a form of non-parametric regression. Useful for scatter plot smoothing. See https://en.wikipedia.org/wiki/Local_regression

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Confidence interval for LOWESS in Python

How would I calculate the confidence intervals for a LOWESS regression in Python? I would like to add these as a shaded region to the LOESS plot created with the following code (other packages than statsmodels are fine as well). import numpy as…
pir
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Fit a line with LOESS in R

I have a data set with some points in it and want to fit a line on it. I tried it with the loess function. Unfortunately I get very strange results. See the plot bellow. I expect a line that goes more through the points and over the whole plot. How…
leo
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Fill region between two loess-smoothed lines in R with ggplot

I'd like to know how to fill the area between to loess-smoothed lines in ggplot. The following data frame is used for the pictures: x y ymin ymax grp ydiff 1 1 3.285614 3.285614 10.14177 min 6.8561586 2 1 10.141773 …
Daniel
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How to use loess method in GGally::ggpairs using wrap function

I am trying to replicate this simple example given in the Coursera R Regression Models course: require(datasets) data(swiss) require(GGally) require(ggplot2) ggpairs(swiss, lower = list(continuous = "smooth", params = c(method = "loess"))) I expect…
meenaparam
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Can't reproduce stat_smooth using `loess` when x-axis is Date

I am using ggplot2 to get a smoothed estimation of my data ggplot(yy)+geom_smooth(aes(x=Date,y=value),method='loess') It works fine. Now, when try to reproduce this using loess function directly, I get an error: loess(value~Date,yy) Error in…
agstudy
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What does the span argument control in geom_smooth?

I am using geom_smooth from the ggplot2 package to create a smoothed line on a time series scatter plot (one point for each day of the year, so I have 365 points). One of the arguments is called span, and going into the help file (?geom_smooth) the…
amccnnll
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loess predict with new x values

I am attempting to understand how the predict.loess function is able to compute new predicted values (y_hat) at points x that do not exist in the original data. For example (this is a simple example and I realize loess is obviously not needed for…
Alex
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R - loess prediction returns NA

I am struggling with "out-of-sample" prediction using loess. I get NA values for new x that are outside the original sample. Can I get these predictions? x <- c(24,36,48,60,84,120,180) y <- c(3.94,4.03,4.29,4.30,4.63,4.86,5.02) lo <-…
Pepacz
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Loess Fit and Resulting Equation

I'm a developer up in Portland, OR. I'm wondering if anyone can assist: I'm working on Loess fit models using R, once I have the fit accomplished, I'm looking to back-out the equation of the fitted non-linear curve, wondering if there is a way…
christian miner
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Difference between R.loess and org.apache.commons.math LoessInterpolator

I'm trying to compute the convert a R script to java using the apache.commons.math library. Can I use org.apache.commons.math.analysis.interpolation.LoessInterpolator in place of R loess ? I cannot get the same result. EDIT. here is a java program…
Pierre
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coplot in R - how to tell which plot is which

I am using coplot in R to plot some conditioning plots: coplot(var1 ~ var2 | var3, data=dtb, number=5, overlap=.1, panel=function(x,y, col, pch) {idx = order(x); lines(x[idx], predict(loess(y ~ x))[idx], pch = pch, col = col)}) How can one tell…
Alex
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How to mark slope changes in LOESS curve using ggplot2?

I have some time-series data that I'm fitting a loess curve in ggplot2, as seen attached. The data takes the shape of an "S" curve. What I really need to find out is the date where the data starts to level off, which looks to be right around time…
user1062293
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loess regression on each group with dplyr::group_by()

Alright, I'm waving my white flag. I'm trying to compute a loess regression on my dataset. I want loess to compute a different set of points that plots as a smooth line for each group. The problem is that the loess calculation is escaping the…
Alex Nesta
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Difficulty plotting data with ggplot2 geom_smooth method=loess?

I'm very new at this and I don't actually understand the differences between the plotting methods, but loess seems to be giving me the most informative graphs, considering I have a small-ish data set (n=~300). I'm trying to split my data by gender…
geedlet
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Setting an upper bound of 0 on a 3d loess smoothing with negative values in R

I have a bit of a bizarre question, but hoping someone can help me. I am attempting to create a surface plot of the bottom of a lake and then add some points showing plant frequency for a visual of where aquatic plants are occurring throughout the…
logicForPresident
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