Make 'subset' method for 'importer' object work with variable name st…

…rings

pkg/DESCRIPTION

@@ -1,8 +1,8 @@
 Package: memisc
 Type: Package
 Title: Management of Survey Data and Presentation of Analysis Results
-Version: 0.99.17
-Date: 2018-10-18
+Version: 0.99.16.1
+Date: 2018-10-20
 Author: Martin Elff (with contributions from Christopher N. Lawrence, Dave Atkins, Jason W. Morgan, Achim Zeileis)
 Maintainer: Martin Elff <memisc@elff.eu>
 Description: An infrastructure for the management of survey data including

pkg/R/importer-methods.R

@@ -149,8 +149,13 @@ setMethod("subset","importer",
         nl <- as.list(1:nvars)
         names(nl) <- names
         cols <- logical(nvars)
-        cols[eval(substitute(select), nl, parent.frame())] <- TRUE
-        select.vars <- sapply(substitute(select)[-1],as.character)
+        if (class(substitute(select)) == 'call') {
+            cols[eval(substitute(select), nl, parent.frame())] <- TRUE
+            select.vars <- sapply(substitute(select)[-1],as.character)
+        } else { # As suggested by Diogo Ferrari (https://dioferrari.com/)
+            select.vars <- select
+            cols[which(names(nl) %in% select.vars )] <- TRUE
+        }
 
     }
     if(nobs < cs) cs <- nobs

pkg/inst/ChangeLog

@@ -1,3 +1,7 @@
+2018-10-20:
+   - The 'subset' method for 'importer' objects now accepts the names of
+     variables to be selected also as a character vector.
+
 2018-10-15:
    - A 'setCodeplan' and 'codeplan<-' assignment function is created that
      can be used to copy the "item structure" or code plan from one object