Revise document about *_var, remove *_var if * is not values.

R/Start.R

@@ -174,13 +174,15 @@
 #'a list with two values can also be provided to take all the indices of the 
 #'values within the specified range.
 #'\cr\cr
-#'The \bold{name of the associated coordinate variable} must be a character 
-#'string with the name of an associated coordinate variable to be found in the 
-#'data files (in all* of them). For this to work, a 'file_var_reader' 
-#'function must be specified when calling Start() (see parameter 
-#''file_var_reader'). The coordinate variable must also be requested in the 
-#'parameter 'return_vars' (see its section for details). This feature only 
-#'works for inner dimensions.
+#'The \bold{name of the associated coordinate variable} '<dimname>_var' must be
+#'a character string with the name of an associated coordinate variable to be 
+#'found in the data files (in all* of them). For this to work, a 
+#''file_var_reader' function must be specified when calling Start() (see 
+#'parameter 'file_var_reader'). '<dimname>_var' is only needed when <dimname> 
+#'is assigned by 'values'. Start() automatically creates 
+#'\code{<dimname_var = '<dimname>'} if it is not specified. The coordinate 
+#'variable must also be requested in the parameter 'return_vars' (see its 
+#'section for details). This feature only works for inner dimensions.
 #'\cr\cr
 #'The \bold{tolerance value} is useful when indices for an inner dimension are 
 #'specified in the third format (values of whichever type). In that case, the 
@@ -1520,6 +1522,16 @@ Start <- function(..., # dim = indices/selectors,
           attr(dat_selectors[[dim_name]], 'values') <- !flag
           attr(dat_selectors[[dim_name]], 'indices') <- flag
         }
+
+        # If xxx_var exists but xxx is not values, remove xxx_var
+        if (dim_name %in% names(var_params) & !(attr(dat_selectors[[dim_name]], 'values'))) {
+          var_params[[dim_name]] <- NULL
+          if (length(var_params) < 1) var_params <- NULL
+          .warning(paste0("Dimension ", dim_name, " is not specified by values while ",
+                          dim_name, "_var is assigned. Remove ", dim_name, "_var from ",
+                          "the call."))
+        }
+
         ## The following code 'rewrites' var_params for all datasets. If providing different
         ## path pattern repositories with different file/inner dimensions, var_params might
         ## have to be handled for each dataset separately.

man/Start.Rd

@@ -512,13 +512,15 @@ indices of the closest values will be retrieved. When using the third format,
 a list with two values can also be provided to take all the indices of the 
 values within the specified range.
 \cr\cr
-The \bold{name of the associated coordinate variable} must be a character 
-string with the name of an associated coordinate variable to be found in the 
-data files (in all* of them). For this to work, a 'file_var_reader' 
-function must be specified when calling Start() (see parameter 
-'file_var_reader'). The coordinate variable must also be requested in the 
-parameter 'return_vars' (see its section for details). This feature only 
-works for inner dimensions.
+The \bold{name of the associated coordinate variable} '<dimname>_var' must be
+a character string with the name of an associated coordinate variable to be 
+found in the data files (in all* of them). For this to work, a 
+'file_var_reader' function must be specified when calling Start() (see 
+parameter 'file_var_reader'). '<dimname>_var' is only needed when <dimname> 
+is assigned by 'values'. Start() automatically creates 
+\code{<dimname_var = '<dimname>'} if it is not specified. The coordinate 
+variable must also be requested in the parameter 'return_vars' (see its 
+section for details). This feature only works for inner dimensions.
 \cr\cr
 The \bold{tolerance value} is useful when indices for an inner dimension are 
 specified in the third format (values of whichever type). In that case, the