afmZeroPointSlope {afmToolkit} | R Documentation |

## Zero Force Point and Slope

### Description

This function finds the point of zero force (real contact point) and the slope of the contact part of the Force-Distance curve.

### Usage

```
afmZeroPointSlope(afmdata, fstar = 0, segment = c("approach", "retract"))
```

### Arguments

`afmdata` |
An |

`fstar` |
Value such that fstar * sd is to be considered as zero Force, where sd is the standard deviation of Force at the basline. It takes fstar = 0 as default value, meaning that zero force is actually zero. |

`segment` |
The segment on which everything is calculated. |

### Value

An `afmdata`

class variable which will consist on the original input
`afmdata`

variable plus a new list named `Slopes`

with the following
fields: `Z0Point`

: Point of zero force. `Slope`

: Slope of the best fit line
in the contact part of the Force-Distance curve.

### Examples

```
data <- afmReadJPK("force-save-JPK-2h.txt.gz", path = path.package("afmToolkit"))
data <- afmContactPoint(data, width = 20, mul1 = 1, mul2 = 20)
data <- afmDetachPoint(data, width = 40, mul1 = 3, mul2 = 40)
data <- afmBaselineCorrection(data)
data <- afmZeroPointSlope(data, segment = "approach")
## Not run:
plot(data, segment = "approach") + geom_vline(xintercept = data$Slopes$Z0Point, lty = 2)
## End(Not run)
```

*afmToolkit*version 0.0.1 Index]