Needs an 'interleaved' dataframe (see interleave function). Pre-test item should be followed by corresponding post-item item etc. Don't knows must be coded as NA. Function handles items without don't know responses. The function is used internally. It calls transmat.
multi_transmat(pre_test = NULL, pst_test = NULL, subgroup = NULL, force9 = FALSE, agg = FALSE)
| pre_test | Required. data.frame carrying responses to pre-test questions. |
|---|---|
| pst_test | Required. data.frame carrying responses to post-test questions. |
| subgroup | a Boolean vector identifying the subset. Default is NULL. |
| force9 | Optional. There are cases where DK data doesn't have DK. But we need the entire matrix. By default it is FALSE. |
| agg | Optional. Boolean. Whether or not to add a row of aggregate transitions at the end of the matrix. Default is FALSE. |
matrix with rows = total number of items + 1 (last row contains aggregate distribution across items) number of columns = 4 when no don't know, and 9 when there is a don't know option
multi_transmat: transition matrix of all the items
pre_test <- data.frame(pre_item1 = c(1,0,0,1,0), pre_item2 = c(1,NA,0,1,0)) pst_test <- data.frame(pst_item1 = pre_test[,1] + c(0,1,1,0,0), pst_item2 = pre_test[,2] + c(0,1,0,0,1)) multi_transmat(pre_test, pst_test)