Show the plots, NCA summaries and bottleneck tables of a NCA analysis.
nca_output(model, plots=TRUE, plotly=FALSE, bottlenecks=FALSE,
summaries=TRUE, test=FALSE, pdf=FALSE, path=NULL, selection = NULL)Displays output of the nca or nca_analysis command
If true (default) show the scatter plot(s), one for each independent variable.
In Rstudio the plots are shown the Plots window.
If true shows the interactive scatter plot(s), one for each independent variable.
In RStudio the plots are shown in the Viewer window. See Details.
If true displays the bottleneck table(s) in the Console window, one table for each ceiling line
If true shows the summaries for each independent variable in the Console window, see Details
If true shows the result of the statistical sigificance test (if present), see Details
If true exports the output to a pdf file, except for the plotly plot
Optional path for the output file(s)
Optionally selects the independent variables for inclusion in the output.
For example, only the plots for the selected independent variable are shown.
In the bottleneck table the required levels of only the selected independent variables for given levels of Y are shown.
Plotly
The plot highlights the points that construct the ceiling line ('peers').
The names and XY coordinates of all points pop up when moving the pointer over the plot.
The toolbar allows several actions such as zoom and selection of parts of the plot. Optionally subgroups of points can be labeled.
Summaries
The output starts with 6 lines of basic information ("global") about the dataset ("Number of observations", "Scope", "Xmin", "Xmax", "Ymin", and "Ymax").
"Scope" refers to the empirical area of possible x-y combinations, given the minimum and maximum observed x and y values.
The next 11 lines present the NCA parameters ("param", see below) for each of the selected ceiling techniques (the defaults techniques are ce_fdh and cr_fdh).
The 11 printed NCA parameters are:
- Ceiling zone, which is the size of the "empty" area in the upper-left corner
- Effect size, which is the ceiling zone divided by the scope
- # above, which is the number of observations that are above the ceiling line and hence in the "empty" ceiling zone
- c-accuracy, which is the number of observations on or below the ceiling line divided by the total number of observations and multiplied by 100 percent
- Fit, which relates to the "closeness" of the selected ceiling line to the ce_fdh ceiling line
- Slope and Intercept, which are the slope and the intercept of the straight ceiling line (no values are printed if the ceiling line is not a straight line, but a step function)
- Abs. ineff., which is the total xy-space where x does not constrain y, and y is not constrained by x
- Rel. ineff., which is the total xy-space where x does not constrain y, and y is not constrained by x as percentage of the scope
- Condition ineff., which is the condition inefficiency that indicates for which range of x (as a percentage of the total range) x does not constrain y (i.e., there is no ceiling line in that x-range)
- Outcome ineff., which is the outcome efficiency that indicates for which range of y (as a percentage of the total range of y) y is not constrained by x (i.e., there is no ceiling line in that y-range)
Test
NCA's statistical test is a randomness test to evaluate if the observed effect size may be a random result of unrelated X and Y variables