# Plot Methods for Various Qval Objects Generate visualizations for objects created by the Qval package. The generic `plot` dispatches to appropriate methods based on object class: - **CDM**: Barplot of attribute-pattern distribution (frequency and proportion). - **sim.data**: Barplot of simulated attribute-pattern distribution (frequency and proportion). - **validation**: Hull plot marking the suggested point in red (method = "Hull"). ```r ## S3 method for class 'CDM' plot(x, ...) ## S3 method for class 'sim.data' plot(x, ...) ## S3 method for class 'validation' plot(x, i = 1, ...) ``` ## Arguments - `x`: An object of class `CDM`, `sim.data`, or `validation`. - `...`: Additional arguments (currently unused). - `i`: For `validation` objects, the index of the item for which to plot the Hull curve. ## Returns None. Functions are called for side effects (plotting). ## Methods (by class) * `plot(CDM)`: Plot method for `CDM` objects * `plot(sim.data)`: Plot method for `sim.data` objects * `plot(validation)`: Hull plot for `validation` objects ## Examples ```r set.seed(123) library(Qval) K <- 4 I <- 20 IQ <- list( P0 = runif(I, 0.2, 0.4), P1 = runif(I, 0.6, 0.8) ) ################################################################ # Example 1: sim.data object # ################################################################ Q <- sim.Q(K, I) data.obj <- sim.data(Q = Q, N = 500, IQ = IQ, model = "GDINA", distribute = "horder") plot(data.obj) ################################################################ # Example 2: CDM object # ################################################################ CDM.obj <- CDM(data.obj$dat, Q, model = "GDINA", method = "EM", maxitr = 2000, verbose = 1) plot(CDM.obj) ################################################################ # Example 3: validation object (Hull plot) # ################################################################ MQ <- sim.MQ(Q, 0.1) CDM.obj <- CDM(data.obj$dat, MQ) ############### ESA ############### Hull.obj <- validation(data.obj$dat, MQ, CDM.obj, method = "Hull", search.method = "ESA") ## plot Hull curve for item 20 plot(Hull.obj, 20) ############### PAA ############### Hull.obj <- validation(data.obj$dat, MQ, CDM.obj, method = "Hull", search.method = "PAA") ## plot Hull curve for item 20 plot(Hull.obj, 20) ```

plot function