Synth 1.1-10

Bug fixes

• synth() and fn.V(): quadopt = "LowRankQP" no longer falls through to undefined-variable code. The deprecation message is now raised via stop() rather than cat(), which matches the user’s expectation that the function fails fast on an unsupported option.

• dataprep(): the missing-data warning loop in the X0 (control predictors) section now iterates over nrow(X0) instead of nrow(X1). Previously it covered only the first length(time.predictors.prior) rows, missing roughly (n_controls - 1) / n_controls of the cells.

• synth(): the error message for ncol(Z0) < 2 no longer mentions “specify only one treated unit” (it is checking for at least two control units).

• path.plot(): Ylim is now padded by a fraction of the data range, not by 0.3 * Y.min. The old formula gave 0.7 * Y.min for negative Y.min, which moved the lower bound toward zero and cropped the bottom of negative-valued series.

Quiet by default

• synth(): messages such as “X1, X0, Z1, Z0 all come directly from dataprep object”, “searching for synthetic control unit”, and the final summary block printing MSPE (LOSS V) and the solution vectors are now gated by verbose = TRUE. With the default verbose = FALSE, synth() runs silently. Set verbose = TRUE to restore the previous chatter.

Documentation / cleanup (no user-visible change)

• Removed dead commented-out collinearity check in synth.R.
• Removed an unreachable is.vector(X0.scaled) defensive branch in synth.R (ncol(X0) < 2 errors out earlier).
• Several typos fixed in error messages: "\ Please..." → "\n Please...", "specificy" → "specify", "on time period" → "one time period", "at least on predictor" → "at least one predictor", "variabale" → "variable", "mispecified" → "misspecified", "supoorted" → "supported", "synthtic" → "synthetic".
• synth() and fn.V(): cleaned up the unsupported-quadopt branch (also clarifies error messages).