Added new statistics plugin

1998-10-02  Richard Hestilow <hestgray@ionet.net>

        * Added new statistics plugin

ChangeLog-1999-07-09

+1998-10-02  Richard Hestilow <hestgray@ionet.net>
+
+	* Added new statistics plugin
+	
 1998-10-02  Jakub Jelinek <jj@sunsite.ms.mff.cuni.cz>
 	
 	* src/dialog-cell-format.c (apply_coloring_format): fix,

ChangeLog-2000-02-23

+1998-10-02  Richard Hestilow <hestgray@ionet.net>
+
+	* Added new statistics plugin
+	
 1998-10-02  Jakub Jelinek <jj@sunsite.ms.mff.cuni.cz>
 	
 	* src/dialog-cell-format.c (apply_coloring_format): fix,

OChangeLog-1999-07-09

+1998-10-02  Richard Hestilow <hestgray@ionet.net>
+
+	* Added new statistics plugin
+	
 1998-10-02  Jakub Jelinek <jj@sunsite.ms.mff.cuni.cz>
 	
 	* src/dialog-cell-format.c (apply_coloring_format): fix,

OChangeLog-2000-02-23

+1998-10-02  Richard Hestilow <hestgray@ionet.net>
+
+	* Added new statistics plugin
+	
 1998-10-02  Jakub Jelinek <jj@sunsite.ms.mff.cuni.cz>
 	
 	* src/dialog-cell-format.c (apply_coloring_format): fix,

configure.in

@@ -91,6 +91,7 @@ plugins/Makefile
 plugins/sample/Makefile
 plugins/python/Makefile
 plugins/perl/Makefile
+plugins/stat/Makefile
 intl/Makefile
 po/Makefile.in
 macros/Makefile

plugins/Makefile.am

@@ -11,4 +11,4 @@ else
 PERL =
 endif
 
-SUBDIRS = sample $(PYTHON) $(PERL)
+SUBDIRS = sample $(PYTHON) $(PERL) stat

plugins/stat/Makefile.am

+#
+# Sample Makefile for a Gnumeric plugin.
+#
+# Where can we find the Gnumeric include files.
+#
+GNUMERIC_SRC_DIR = $(srcdir)/../../src
+
+#
+# Where to install the plugin
+#
+plugindir = $(libdir)/gnumeric/plugins
+
+CFLAGS += -g -Wall 	\
+	-Wshadow             -Wpointer-arith  	\
+	-Wmissing-prototypes -Wmissing-declarations 
+
+plugin_LTLIBRARIES = libstat.la
+
+libstat_la_SOURCES = stat.c stat.h
+
+INCLUDES = 						\
+	-I$(GNUMERIC_SRC_DIR)				\
+	-DGNOMELOCALEDIR=\""$(datadir)/locale"\" 	\
+	-I$(includedir)					\
+	$(GNOME_INCLUDEDIR)

plugins/stat/stat.c

+/* Statistics Plugin
+ *
+ * Richard Hestilow <hestgray@ionet.net>
+ */
+
+#include "stat.h"
+#include <math.h>
+
+static char *help_stat_stdev = { 
+	N_("@FUNCTION=STDEV\n"
+	"@SYNTAX = STDEV(value1, value2, ...)"
+	"@DESCRIPTION="
+	"Computes the standard deviation of all the values and cells"
+	" referenced in the argument list. This is equivalent to the square "
+	"root of the variance."
+	"\n"
+	"@SEEALSO=VARIANCE")
+};			
+				
+static char *help_stat_variance = {
+	N_("@FUNCTION=VARIANCE\n"
+	"@SYNTAX = VARIANCE(value1, value2, ...)"
+	"@DESCRIPTION="
+	"Computes the variation of all the values and cells referenced in the "
+	"argument list. This is	equivalent to the sum of (value - average)^2, "
+	"divided by the number of values minus 1."
+	"@SEEALSO=AVERAGE")
+};
+
+static FunctionDefinition plugin_functions[] = {
+	{"stdev", "", "", &help_stat_stdev, stat_stdev, NULL },
+	{"variance", "", "", &help_stat_variance, stat_variance, NULL },
+	{ NULL, NULL },};
+
+
+static int can_unload(PluginData *pd) {
+	Symbol *sym;
+	sym = symbol_lookup("stat_variance");
+	return sym->ref_count <= 1;
+}
+	
+int init_plugin (PluginData *pd) {
+	install_symbols(plugin_functions);
+	pd->can_unload = can_unload;
+	pd->cleanup_plugin = cleanup_plugin;
+	pd->title = g_strdup("Statistics Plugin");
+	return 0;
+}
+
+static void cleanup_plugin (PluginData *pd) {
+	Symbol *sym;
+	unsigned int i;
+	
+	g_free (pd->title);
+	
+	for(i=0;i<(((sizeof(plugin_functions))/(sizeof(FunctionDefinition)))-1);i++)  {
+	sym = symbol_lookup(plugin_functions[i].name);
+	if (sym) 
+			symbol_unref(sym);
+	}
+}
+
+static Value *stat_variance(void *sheet, GList *expr_node_list, int eval_col,
+				int eval_row, char **error_string) {
+	Value *result, *avg, *tmpval;
+	GPtrArray *values;
+	gpointer *pdata;	
+	float tmp;
+	unsigned int i;
+	
+	values = g_ptr_array_new();
+	result = g_new(Value, 1);
+	result->type = VALUE_FLOAT;
+	result->v.v_float = 0.0;
+	
+	
+	function_iterate_argument_values(sheet, callback_var, values,
+					expr_node_list, eval_col, eval_row,
+					error_string);
+	avg = function_call_with_values(sheet, "average", values->len, 
+			values->pdata, error_string);
+	
+	for(i=0;i<(values->len); i++) {
+		tmpval = g_ptr_array_index(values, i);
+		tmp = tmpval->v.v_float - value_get_as_double(avg);
+		tmp *= tmp;
+		result->v.v_float += tmp;
+	}
+	result->v.v_float /= values->len - 1;
+	
+	return result;
+}
+
+static Value *stat_stdev(void *sheet, GList *expr_node_list, int eval_col,                               int eval_row, char **error_string) {
+	Value *result, *var;
+	
+	result = g_new(Value, 1);
+	result->type = VALUE_FLOAT;
+	result->v.v_float = 0.0;
+
+	var = stat_variance(sheet, expr_node_list, eval_col, eval_row,
+				error_string);
+
+	result->v.v_float = sqrt(var->v.v_float);
+
+	return result;
+}
+	
+
+int callback_var ( Sheet *sheet, Value *value, char **error_string, 
+		void *closure) {
+	GPtrArray *values = (GPtrArray *) closure;
+
+	float tmp;
+	tmp =value_get_as_double(value);
+	value->v.v_float = tmp;
+	value->type = VALUE_FLOAT;
+	g_ptr_array_add(values, g_memdup(value, sizeof(*value)));
+	return TRUE;
+}
+
+
+			

plugins/stat/stat.h

+#ifndef GNUMERIC_STAT_H
+#define GNUMERIC_STAT_H
+
+#include <glib.h>
+#include <gnome.h>
+#include "../../src/gnumeric.h"
+#include "../../src/func.h"
+#include "../../src/plugin.h"
+
+static Value *stat_stdev (void *sheet, GList *expr_node_list, int eval_col,
+				int eval_row, char **error_string);
+
+static Value *stat_variance(void *sheet, GList *expr_node_list, int eval_col,
+				int eval_row, char **error_string);
+
+int callback_var(Sheet *sheet, Value *value, 
+		char **error_string, void *closure);
+static void cleanup_plugin(PluginData *pd);
+int init_plugin(PluginData *pd);
+
+#endif /* GNUMERIC_STAT_H */