windowedFit {afmToolkit} | R Documentation |

## Linear fit in a running window

### Description

This is an internal function used by the `afmContactPoint`

and `afmDetachPoint`

functions.
It computes the slopes of a linear fit to the data in a window of a given radius.
This function should not be used directly unless by experienced users.

### Usage

```
windowedFit(X, width)
```

### Arguments

`X` |
Least squares matrix on the form [1 z Force],
according to input parameters in function |

`width` |
Width of the window for the local regression (in vector position units) |

### Value

`OUT`

A vector of length `nrow(X)-2*width`

,
containing with the slopes of the fits.

### Examples

```
n <- 100
x <- seq(0,2*pi,length.out = n)
y = sin(x)+0.1*rnorm(n)
X <- matrix(c(rep(1,n),x,y),nrow = n,ncol = 3)
width <- 5
b <- windowedFit(X,width)
plot(x[(width+1):(n-width)],b,xlab = "x",ylab = "y",type = "l")
lines(x,y,col = "red")
legend("bottomleft",c("Slopes","Signal"),col = c(1,2),lty = 1)
```

[Package

*afmToolkit*version 0.0.1 Index]