stiffnessSphereOnPlane: Extract Sample Stiffness From Force Curves
In nstone8/Rasylum: Rasylum: AFM Data Analysis in R

Perform a fit of force curves to a Hertzian contact model to estimate the Young's modulus of a sample.

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stiffnessSphereOnPlane(rBead, extZ, extForce, CPMaxF=.05,
percentToFit=0.2, roughness=.01, Q=.5, approachTrim=0.2, debug=FALSE)
parExtractStiffness(rBead, cases, zPos="zSensr", force="force", CPMaxF=.05, percentToFit=0.2, roughness=0.05,Q=.5, approachTrim=0.2, debug=FALSE, minRise=0, numCores=-1)

`rBead`	Radius of the spherical indenter used, in meters
`extZ`	Column vector containing z position data
`extForce`	Column containing force data
`CPMaxF`	The percentage of the maximum force beyond which this function will not search for the contact point. This is the default contact point if other methods fail.
`percentToFit`	Percentage of the extension curve that will be used to perform the fits
`roughness`	The percentage of the force range features must be larger than to not be considered noise
`Q`	The minimum ratio of height to width a trough on a residual vs. contact point plot has to have to be considered a local minima.
`approachTrim`	The percentage of the beginning of a curve to be trimmed off before performing fitting
`debug`	If TRUE, each fit will be displayed to the user, who should press 'enter' at the command prompt to cycle through the fits. This functionality is intended to be used for tuning of fit parameters
`cases`	An object of the type produced by `loadPreSorted` containing the force curves to be fit to the Hertzian Contact Model
`zPos`	The name of the columns containing the z position data
`force`	the name of the columns containing the force data
`minRise`	The percentage of the total force range that the fit curve must traverse to not be considered degenerate. Degenerate curves will be refit
`numCores`	Number of cores to use for the computation. If `numCores`==-1 all available cores will be used

An object containing the extracted stiffness values, fit residuals and the fit curves themselves. Fit curves can be saved using saveFits, other data can be formatted into a human-readable data.frame using collateFits.

nstone8/Rasylum documentation built on May 9, 2019, 8:18 a.m.