Objects can be created by calls of the form new("SGP", ...), but this is not encouraged. To instantiate a new instance of SGP class use the function prepareSGP instead.
is.SGP(x)
Data:A data.table including student-level data in a (long) format. For annual testing, each VALID_CASE, CONTENT_AREA, YEAR, ID combination represents a unique case in the data. For instances with multiple tests within a year, each VALID_CASE, CONTENT_AREA, YEAR, ID, WITHIN_YEAR combination represents a unique case in the data. See sgpData_LONG for an exemplar data set
Data_Supplementary:A list (possibly NULL) providing additional data.tables containing student level multiple-membership lookup tables. For example, sgpData_INSTRUCTOR_NUMBER provides student teacher linkages and can be embedded in this slot using a list that contains it.
Names:A data.frame with five columns: 'names.provided', 'names.sgp', 'names.type', 'names.info', 'names.output'. This data.frame is used as a lookup table to translate state specific variable names to SGP variable names as well as provide information for summarizeSGP on the types of summary tables to produce.
SGP:A list including the output from analyzeSGP
Summary:A list including the output from summarizeSGP
Version:A list of meta-data including the version of the SGP package used to construct the SGP object and the date the object was created.
combines class list and class NULL