Hi,
A frequently seen issue with importing SPSS data files, is that R does
not import the 'long variable names'.
I built a patch on the R-project's foreign module, in order to import
the 'long variable names' from SPSS (record 7, subtype 13).
To complete the job, I had to expand the "struct variable" definition
to have 64 +1 charachters. I'm not aware of side effects.
The sfm-read.c code works fine.
I didn't test a variety of platforms, as I don't have an idea of what is
regarded as sufficient testing. Anyway, I don't expect major troubles there
(no byteswapping problems, no 32<->64 bit issues) as it's mainly character
processing.
The patch is relative to the foreign directory. It was created
against the trunk of R-project yesterday.
We would appreciate that you import such patch into the main tree.
Kind regards,
Kurt Van Dijck (C programmer) & Ilse Laurijssen (R user)
Belgium
Index: src/sfm-read.c
===================================================================
--- src/sfm-read.c (revision 5168)
+++ src/sfm-read.c (working copy)
@@ -188,6 +188,8 @@
static int read_variables (struct file_handle * h, struct variable ***
var_by_index);
static int read_machine_int32_info (struct file_handle * h, int size, int
count, int *encoding);
static int read_machine_flt64_info (struct file_handle * h, int size, int
count);
+static int read_long_var_names (struct file_handle * h, struct dictionary *
+ , unsigned long size, unsigned int count);
static int read_documents (struct file_handle * h);
/* Displays the message X with corrupt_msg, then jumps to the lossage
@@ -418,11 +420,15 @@
break;
case 7: /* Multiple-response sets (later versions of SPSS). */
- case 13: /* long variable names. PSPP now has code for these
- that could be ported if someone is interested. */
skip = 1;
break;
+ case 13: /* long variable names. PSPP now has code for these
+ that could be ported if someone is interested. */
+ if (!read_long_var_names(h, ext->dict, data.size, data.count))
+ goto lossage;
+ break;
+
case 16: /* See
http://www.nabble.com/problem-loading-SPSS-15.0-save-files-t2726500.html */
skip = 1;
break;
@@ -584,14 +590,72 @@
return 0;
}
+/* Read record type 7, subtype 13.
+ * long variable names
+ */
static int
+read_long_var_names (struct file_handle * h, struct dictionary * dict
+ , unsigned long size, unsigned int count)
+{
+ char * data;
+ unsigned int j;
+ struct variable ** lp;
+ struct variable ** end;
+ char * p;
+ char * endp;
+ char * val;
+ if ((1 != size)||(0 == count)) {
+ warning("%s: strange record info seen, size=%u, count=%u"
+ ", ignoring long variable names"
+ , h->fn, size, count);
+ return 0;
+ }
+ size *= count;
+ data = Calloc (size +1, char);
+ bufread(h, data, size, 0);
+ /* parse */
+ end = &dict->var[dict->nvar];
+ p = data;
+ do {
+ if (0 != (endp = strchr(p, '\t')))
+ *endp = 0; /* put null terminator */
+ if (0 == (val = strchr(p, '='))) {
+ warning("%s: no long variable name for variable '%s'", h->fn, p);
+ } else {
+ *val = 0;
+ ++val;
+ /* now, p is key, val is long name */
+ for (lp = dict->var; lp < end; ++lp) {
+ if (!strcmp(lp[0]->name, p)) {
+ strncpy(lp[0]->name, val, sizeof(lp[0]->name));
+ break;
+ }
+ }
+ if (lp >= end) {
+ warning("%s: long variable name mapping '%s' to '%s'"
+ "for variable which does not exist"
+ , h->fn, p, val);
+ }
+ }
+ p = &endp[1]; /* put to next */
+ } while (endp);
+
+ free(data);
+ return 1;
+
+lossage:
+ free(data);
+ return 0;
+}
+
+static int
read_header (struct file_handle * h, struct sfm_read_info * inf)
{
struct sfm_fhuser_ext *ext = h->ext; /* File extension strcut. */
struct sysfile_header hdr; /* Disk buffer. */
struct dictionary *dict; /* File dictionary. */
char prod_name[sizeof hdr.prod_name + 1]; /* Buffer for product name. */
- int skip_amt = 0; /* Amount of product name to omit. */
+ int skip_amt = 0; /* Amount of product name to omit. */
int i;
/* Create the dictionary. */
@@ -1495,7 +1559,7 @@
/* Reads one case from system file H into the value array PERM
according to the instructions given in associated dictionary DICT,
which must have the get.* elements appropriately set. Returns
- nonzero only if successful. */
+ nonzero only if successful. */
int
sfm_read_case (struct file_handle * h, union value * perm, struct dictionary *
dict)
{
Index: src/var.h.in
===================================================================
--- src/var.h.in (revision 5168)
+++ src/var.h.in (working copy)
@@ -41,6 +41,10 @@
#error MAX_SHORT_STRING must be less than 8.
#endif
+/* VAR_NAME_LEN: the length of a variable.
+ * SPSS supports names of 64 long
+ */
+#define VAR_NAME_LEN 64
/* Special values. */
#define SYSMIS (-DBL_MAX)
#define LOWEST second_lowest_double_val()
@@ -228,7 +232,7 @@
/* MODIFY VARS private data. */
struct modify_vars_proc
{
- char new_name[9]; /* Variable's new name. */
+ char new_name[VAR_NAME_LEN +1]; /* Variable's new name. */
int drop_this_var; /* 0=keep this var, 1=drop this var. */
struct variable *next; /* Next in linked list. */
};
@@ -302,7 +306,7 @@
struct variable
{
/* Required by parse_variables() to be in this order. */
- char name[9]; /* As a string. */
+ char name[VAR_NAME_LEN +1]; /* As a string. */
int index; /* Index into its dictionary's var[]. */
int type; /* NUMERIC or ALPHA. */
int foo; /* Used for temporary storage. */
@@ -373,9 +377,9 @@
int weight_index; /* `value' index of $WEIGHT, or -1 if none.
Call update_weighting() before using! */
- char weight_var[9]; /* Name of WEIGHT variable. */
+ char weight_var[VAR_NAME_LEN];/* Name of WEIGHT variable. */
- char filter_var[9]; /* Name of FILTER variable. */
+ char filter_var[VAR_NAME_LEN];/* Name of FILTER variable. */
/* Do not make another field the last field! or see
temporary.c:restore_dictionary() before doing so! */
};
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