Linked Questions

10
votes
2answers
10k views

Equation of a fitted smooth spline and its analytical derivative [duplicate]

I need to fit a spline function to a data set. I tried with bs, ns and smooth.spline. In my ...
0
votes
0answers
2k views

restricted cubic spline interpretation [duplicate]

My question regards both the interpretation and use of restricted cubic spline coefficients when used in a linear regression. so in the example below how would i combine the coefficients to get the ...
0
votes
0answers
45 views

Piece Wise Linear Interpretation in R and plotting with ggplot [duplicate]

I've been able to fit a piece wise linear fit to my data set using Rs splines2 package. I'm hoping someone could help me with interpretation and vizualization. Here is the model code: ...
111
votes
5answers
19k views

What skills are required to perform large scale statistical analyses?

Many statistical jobs ask for experience with large scale data. What are the sorts of statistical and computational skills that would be need for working with large data sets. For example, how about ...
13
votes
1answer
5k views

How to translate the output from an lm() fit with a cubic spline into a regression equation

I have some code and output, and I would like to construct a model. I don't know how to construct a model using this output: ...
5
votes
1answer
7k views

Fitted model of linear spline regression in R

If the linear model is fitted as follows, what is the formula of the fitted model? I need to use the coefficients outside R. ...
8
votes
2answers
1k views

Splines - basis functions - clarification

I have been reading the very helpful introduction on splines on http://freakonometrics.hypotheses.org/9184 and on http://www.stats.uwo.ca/faculty/braun/ss3859/chapters/splines/splines.pdf, as well as ...
2
votes
2answers
355 views

Generalized Additive Model Form

I have a GAM and I want to make an Excel-based calculator to give the predicted value. I have done this for GLMs in the past as: $$ \Large \textrm{Predicted value} = e^{\left(\beta_0 + \beta_1 x_1 + \...
0
votes
1answer
327 views

splinefun build in function in R-programming

> t<-seq(0,1,len=5) > x<-matrix(c(1.3,2.3,21,2.4,3.8,9,4.5,11.3,4.2,7.8),2) > s1 <- splinefun(t, colMeans(x), method = "monoH.FC") > plot(s1) ...
1
vote
0answers
364 views

Understanding the Math of Segmented and Splines2 packages.

I was trying to teach myself the math behind what produces the slope and intercept of a segmented variable in the segmented package using the plant data set. My ...
0
votes
2answers
101 views

How to find all models that meet the pre-specified restrictions

Let's say I have a large number of predictors (e.g. 2000) and I'm facing the problem of choosing the linear regression model under following assumptions: There are few predictors that have to be ...
2
votes
1answer
91 views

Data Transformation to achieve Linearity

One assumption of OLS regression is Linearity. To check whether the assumption holds, you can plot component + residual plots or partial residual plots. When a linear relationship is apparent, is's ...
2
votes
0answers
46 views

R - How can I fit the following data and get the equation describing them? [closed]

I have a following data-set: ...