check.expr.Rd
Test: Compare the expression check.expr evaluated in the student's environment with the solution correct.expr
check.expr( check.expr, correct.expr, failure.message = "{{check_expr}} has the wrong values!", success.message = "Great, {{check_expr}} seems correct.", part = NULL, ps = get.ps(), stud.env = ps$stud.env, verbose = FALSE, unsubst.check.expr = NULL, unsubst.correct.expr = NULL, str.check.expr = NULL, str.correct.expr = NULL, tol = .Machine$double.eps^0.5 )
check.expr | the expression to be checked |
---|---|
correct.expr | the correct expression |
vars | a variable name or vector of variable names |
exists | shall existence be checked (similar length, class, values) |
failure.exists | a message that is shown if the variable does not exists (similar the other failure.??? variables) |
failure.message.add | a text that will be added to all failure messages |