PhiCoefficient {exametrika} | R Documentation |
Phi-Coefficient
Description
The phi coefficient is the Pearson's product moment correlation coefficient between two binary items. This function is applicable only to binary response data. The coefficient ranges from -1 to 1, where 1 indicates perfect positive correlation, -1 indicates perfect negative correlation, and 0 indicates no correlation.
Usage
PhiCoefficient(U, na = NULL, Z = NULL, w = NULL)
## Default S3 method:
PhiCoefficient(U, na = NULL, Z = NULL, w = NULL)
## S3 method for class 'binary'
PhiCoefficient(U, na = NULL, Z = NULL, w = NULL)
Arguments
U |
Either an object of class "exametrika" or raw data. When raw data is given,
it is converted to the exametrika class with the |
na |
Values to be treated as missing values. |
Z |
Missing indicator matrix of type matrix or data.frame. Values of 1 indicate observed responses, while 0 indicates missing data. |
w |
Item weight vector specifying the relative importance of each item. |
Value
A matrix of phi coefficients with exametrika class. Each element (i,j) represents the phi coefficient between items i and j. The matrix is symmetric with ones on the diagonal.
Note
This function is implemented using a binary data compatibility wrapper and will raise an error if used with polytomous data.
Examples
# example code
# Calculate Phi-Coefficient using sample dataset J15S500
PhiCoefficient(J15S500)