Reaching endpoint accuracy and precision

Computes constant, variable, absolute, and root-mean-square endpoint error. Variable error uses the population RMS distance about the endpoint centroid, preserving the identity RMSE^2 = constant_error^2 + variable_error^2.

Usage

endpointError(endpoints, target)

Arguments

endpoints

Numeric endpoint vector for a one-dimensional task, or an n by 2/3 numeric matrix with one endpoint per row.

target

Numeric target scalar or vector matching the endpoint dimension.

Value

A reaching_endpoint_error object with constant, variable, absolute, RMS, and Fitts effective-width errors.

References

Hancock GR, Butler MS, Fischman MG (1995). On the problem of two-dimensional error scores: measures and analyses of accuracy, bias, and consistency. Journal of Motor Behavior, 27:241-250.

Fitts PM (1954). The information capacity of the human motor system in controlling the amplitude of movement. Journal of Experimental Psychology, 47:381-391. doi:10.1037/h0055392

Examples

endpointError(c(11, 12, 13, 12), target = 10)
#> <reaching_endpoint_error> n=4, dimension=1
#>   constant: 2  variable: 0.7071  absolute: 2
#>   RMSE: 2.121  effective width: 2.922