names corrections in sarima_estimate

R/arima.R

@@ -323,11 +323,24 @@ sarima_estimate<-function(x, order=c(0,0,0), seasonal = list(order=c(0,0,0), per
   bytes<-.jcall("jdplus/toolkit/base/r/arima/SarimaModels", "[B", "toBuffer", jestim)
   p<-RProtoBuf::read(regarima.RegArimaModel$Estimation, bytes)
   res <- .p2r_regarima_estimation(p)
-  names_xreg <- colnames(xreg)
-  if (mean) {
-    names_xreg <- c("intercept", names_xreg)
+
+  if (length(res$b) > 0) {
+
+    names_xreg <- colnames(xreg)
+    if (is.null (names_xreg) & !is.null (xreg)){
+      if (is.matrix(xreg)) {
+        # unnamed matrix regressors
+        names_xreg <- sprintf("xreg_%i", seq_len(ncol(xreg)))
+      } else {
+        # vector external regressor
+        names_xreg <- "xreg_1"
+      }
+    }
+    if (mean) {
+      names_xreg <- c("intercept", names_xreg)
+    }
+    names(res$b) <- names_xreg
   }
-  names(res$b) <- names_xreg
   names(res$parameters$val) <- c(sprintf("phi(%i)", seq_len(order[1])),
                                  sprintf("bphi(%i)", seq_len(seasonal$order[1])),
                                  sprintf("theta(%i)", seq_len(order[3])),