| angles {D3mirt} | R Documentation |
Standard Angles Data Frame
Description
A test unit data frame consisting of 42 rows and 6 columns with standard angles in Cartesian coordinates as item loadings (columns denoted a1, a2, and a3) oriented in both positive and negative directions in a three-dimensional space.
The distance from the origin is set by d = 0,5 (4th column) on all rows, which refers to the parameter related to difficulty in the compensatory model.
The last two columns contain the angles converted to spherical coordinates with Theta representing the polar angle and Phi representing the azimuthal angle.
Running the data frame in D3mirt() converts the angles into spherical coordinates and can be used to check functionality in the package.
Note, Nan, i.e., "not-a-number", appears in the D3mirt() output because the \arctan function (used when changing to spherical coordinates) is not defined when cosine equals zero.
Usage
angles
Format
An object of class data.frame with 42 rows and 6 columns.
Examples
data(angles)