nlmePredict_PS: Estimation of the print size value necessary to achieve a...
In mnreadR: MNREAD Parameters Estimation and Curve Plotting

Description Usage Arguments Value Notes See Also Examples

This function uses results from the NLME model created with nlmeModel to estimate the print size value required to achieve a specific reading speed.

1	nlmePredict_PS(nlme.model, reading.speed)

`nlme.model`	The object returned by `nlmeModel`
`reading.speed`	A specific value of reading speed in words/minute

The function returns a dataframe with a with two variables:

"reading_speed" -> the reading speed value passed to the function (in words/min)
"required_print_size" -> the print size required to achieve the reading speed value passed to the function (in logMAR)

The values of print size returned have been corrected for non-standard testing viewing distance.

For more details on the nlme fit, see:\ Cheung SH, Kallie CS, Legge GE, Cheong AM. Nonlinear mixed-effects modeling of MNREAD data. Invest Ophthalmol Vis Sci. 2008;49:828–835. doi: 10.1167/iovs.07-0555.

nlmeModel to fit MNREAD data using a nonlinear mixed-effect (NLME) modeling

nlmeParam to estimate Maximum Reading Speed (MRS) and Critical Print Size (CPS) from the NLME model

nlmeCurve to plot the individual MNREAD curves estimated from the NLME model

# inspect the structure of the dataframe
head(data_low_vision, 10)

#------

# restrict dataset to one MNREAD test per subject (regular polarity only)
data_regular <- data_low_vision %>%
    filter (polarity == "regular")

# run the NLME model for data grouped by subject
## Not run:  nlme_model <- nlmeModel(data_regular, ps, vd, rt, err, subject) 

#------

# extract the critical print size required 
# to achieve 40 words/min (ie. spot reading) according to the NLME fit 
## Not run:  nlmePredict_PS(nlme_model, 40) 

#------

# extract the critical print size required 
# to achieve 80 words/min (ie. fluent reading) according to the NLME fit 
## Not run:  nlmePredict_PS(nlme_model, 80)