OrdVarCoordinates function

Coordinates of an ordinal variable on the biplot.

OrdVarCoordinates(tr, b = c(1, 1), inf = -12, sup = 12, step = 0.01,
                 plotresponse = FALSE, label = "Item", labx = "z", laby
                 = "Probability", catnames = NULL, Legend = TRUE,
                 LegendPos = 1)

Arguments

• tr: A vector containing the thresholds of the model, that is, the constatn for each category of the ordinal variable
• b: Vector containing the common slopes for all categories of the ordinal variable
• inf: The inferior limit of the values to be sampled on the biplot axis (it depends on the scale of the biplot).
• sup: The superior limit of the values to be sampled on the biplot axis (it depends on the scale of the biplot).
• step: Increment (step) of the squence
• plotresponse: Should the item be plotted
• label: Label of the item.
• labx: Label for the X axis in the summary of the item.
• laby: Label for the Y axis in the summary of the item.
• catnames: Names of the categories.
• Legend: Should a legend be plotted
• LegendPos: Position of the legend.

Details

The function calculates the coordinates of the points that define the separation among the categories of an ordinal variable projected onto an ordinal logistic biplot.

Returns

An object of class OrdVarCoord - z: Values of the cut points on the scale of the biplot axis (not used)

• points: The points for the marks to be represented on the biplot.

• labels: The labels for the points

• hidden: Are there any hidden categories? (Categories whose probability is never hier than the probabilities of the rest)

• cathidden: Number of the hidden cateories

References

Vicente-Villardon, J. L., & Sanchez, J. C. H. (2014). Logistic Biplots for Ordinal Data with an Application to Job Satisfaction of Doctorate Degree Holders in Spain. arXiv preprint arXiv:1405.0294.

Author(s)

Jose Luis Vicente Villardon

Examples

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