New statistical functions and testing framework

New functions:

* percentile_cont
* percentile_disc
* stat_mode

Fixes:

* median now returns correct value for even number of rows

Tests for:

* corr
* median
* percentile_cont
* percentile_disc
* stat_mode

Makefile.am

@@ -1,5 +1,5 @@
 ACLOCAL_AMFLAGS = -I m4
-SUBDIRS = src
+SUBDIRS = src test
 EXTRA_DIST = load.sql unload.sql
 BUILT_SOURCES = load.sql unload.sql
 CLEANFILES = load.sql unload.sql
@@ -12,4 +12,13 @@ load.sql:
 unload.sql:
 	sh unload.sql.sh $(enable_functions) > unload.sql
 
-.PHONY: load.sql unload.sql
+load:
+	mysql $(MYSQL_OPTIONS) < load.sql
+
+unload:
+	mysql $(MYSQL_OPTIONS) < unload.sql
+
+test test_prepare test_clean: all
+	cd test && $(MAKE) $(AM_MAKEFLAGS) $@
+
+.PHONY: load.sql unload.sql load unload test test_preapre test_clean

Makefile.in

@@ -144,6 +144,10 @@ CCDEPMODE = @CCDEPMODE@
 CFLAGS = @CFLAGS@
 CPP = @CPP@
 CPPFLAGS = @CPPFLAGS@
+CXX = @CXX@
+CXXCPP = @CXXCPP@
+CXXDEPMODE = @CXXDEPMODE@
+CXXFLAGS = @CXXFLAGS@
 CYGPATH_W = @CYGPATH_W@
 DEFS = @DEFS@
 DEPDIR = @DEPDIR@
@@ -207,6 +211,7 @@ abs_top_builddir = @abs_top_builddir@
 abs_top_srcdir = @abs_top_srcdir@
 ac_ct_AR = @ac_ct_AR@
 ac_ct_CC = @ac_ct_CC@
+ac_ct_CXX = @ac_ct_CXX@
 ac_ct_DUMPBIN = @ac_ct_DUMPBIN@
 am__include = @am__include@
 am__leading_dot = @am__leading_dot@
@@ -255,7 +260,7 @@ top_build_prefix = @top_build_prefix@
 top_builddir = @top_builddir@
 top_srcdir = @top_srcdir@
 ACLOCAL_AMFLAGS = -I m4
-SUBDIRS = src
+SUBDIRS = src test
 EXTRA_DIST = load.sql unload.sql
 BUILT_SOURCES = load.sql unload.sql
 CLEANFILES = load.sql unload.sql
@@ -780,7 +785,16 @@ load.sql:
 unload.sql:
 	sh unload.sql.sh $(enable_functions) > unload.sql
 
-.PHONY: load.sql unload.sql
+load:
+	mysql $(MYSQL_OPTIONS) < load.sql
+
+unload:
+	mysql $(MYSQL_OPTIONS) < unload.sql
+
+test test_prepare test_clean: all
+	cd test && $(MAKE) $(AM_MAKEFLAGS) $@
+
+.PHONY: load.sql unload.sql load unload test test_preapre test_clean
 
 # Tell versions [3.59,3.63) of GNU make to not export all variables.
 # Otherwise a system limit (for SysV at least) may be exceeded.

README.md

@@ -33,7 +33,7 @@ option:
 ./configure --enable-functions="<list-of-functions>"
 ```
 
-where `<list-of-functions>` is a space-separated list of function names.
+where `<list-of-functions>` is a list of function names separated by space.
 
 ### Uninstall
 
@@ -109,6 +109,25 @@ int lessavg(double m);
 mysql> SELECT lessavg(double m) from t1;
 ```
 
+
+Calculate continuous percentile. Returns the value at a relative position
+specified by the fraction, interpolating between input values if needed.
+```
+double percentile_cont(double x, double fraction);
+
+mysql> SELECT percentile_cont(x, 0.5) from t1;
+```
+
+
+Calculate discrete percentile. Returns the first input value whose relative
+position is greater than or equal to the specified fraction.
+```
+double percentile_disc(double x, double fraction);
+
+mysql> SELECT percentile_disc(x, 0.5) from t1;
+```
+
+
 Calculates the 3th statistical moment of a data set: skewness
 See: http://geography.uoregon.edu/geogr/topics/moments.htm
 ```
@@ -117,6 +136,15 @@ double skewness(double m);
 mysql> SELECT skewness(double m) from t1;
 ```
 
+
+Find statistical mode, i.e. the most frequent input value.
+```
+double stat_mode(double x);
+
+mysql> SELECT stat_mode(double x) from t1;
+```
+
+
 Calculates the 4th statistical moment of a data set: kurtosis
 See: http://geography.uoregon.edu/geogr/topics/moments.htm
 ```
@@ -356,6 +384,53 @@ mysql> SELECT SETINT(4283942, 4, 8, 10);
 1 row in set (0.00 sec)
 ```
 
+Testing
+=======
+
+udf_infusion contains a set of unit tests to verify the correctness
+of the provided UDF functions. Running them after installation is optional.
+
+Prerequisites:
+
+* Python 2.7
+* [numpy](http://www.numpy.org/)
+* [scipy](http://scipy.org/)
+
+**Note**: The testing framework requires all UDF functions to be enabled
+during installation.
+
+First, it is recommended you set connection details (incl. password) in
+`~/.my.cnf`, e.g.:
+
+```
+[client]
+user=<user>
+password=<password>
+```
+
+Alternatively, you can set options to be passed to the MySQL client
+in the `MYSQL_OPTIONS` environment variable.
+
+To prepare the testing environment (requires administrator rights in MySQL):
+
+```
+make test_prepare
+```
+
+This may take a while as sample data are generated and imported.
+Database `udf_infusion_test` is created and populated with generated data.
+
+Run tests with:
+
+```
+make test
+```
+
+After completion, the temporary database can dropped with `test_clean`:
+
+```
+make test_clean
+```
 
 License
 ======

config.h

@@ -0,0 +1,78 @@
+/* config.h.  Generated from config.h.in by configure.  */
+/* config.h.in.  Generated from configure.ac by autoheader.  */
+
+/* Define to 1 if you have the <dlfcn.h> header file. */
+#define HAVE_DLFCN_H 1
+
+/* Define to 1 if you have the <inttypes.h> header file. */
+#define HAVE_INTTYPES_H 1
+
+/* Define to 1 if you have the <limits.h> header file. */
+#define HAVE_LIMITS_H 1
+
+/* Define to 1 if you have the <memory.h> header file. */
+#define HAVE_MEMORY_H 1
+
+/* Define to 1 if MySQL libraries are available */
+#define HAVE_MYSQL 1
+
+/* Define to 1 if you have the <stdint.h> header file. */
+#define HAVE_STDINT_H 1
+
+/* Define to 1 if you have the <stdlib.h> header file. */
+#define HAVE_STDLIB_H 1
+
+/* Define to 1 if you have the <strings.h> header file. */
+#define HAVE_STRINGS_H 1
+
+/* Define to 1 if you have the <string.h> header file. */
+#define HAVE_STRING_H 1
+
+/* Define to 1 if you have the <syslimits.h> header file. */
+/* #undef HAVE_SYSLIMITS_H */
+
+/* Define to 1 if you have the <sys/stat.h> header file. */
+#define HAVE_SYS_STAT_H 1
+
+/* Define to 1 if you have the <sys/types.h> header file. */
+#define HAVE_SYS_TYPES_H 1
+
+/* Define to 1 if you have the <unistd.h> header file. */
+#define HAVE_UNISTD_H 1
+
+/* Define to the sub-directory in which libtool stores uninstalled libraries.
+   */
+#define LT_OBJDIR ".libs/"
+
+/* Name of package */
+#define PACKAGE "lib_udf_infusion"
+
+/* Define to the address where bug reports for this package should be sent. */
+#define PACKAGE_BUGREPORT "robert@xarg.org"
+
+/* Define to the full name of this package. */
+#define PACKAGE_NAME "lib_udf_infusion"
+
+/* Define to the full name and version of this package. */
+#define PACKAGE_STRING "lib_udf_infusion 1.0"
+
+/* Define to the one symbol short name of this package. */
+#define PACKAGE_TARNAME "lib_udf_infusion"
+
+/* Define to the home page for this package. */
+#define PACKAGE_URL ""
+
+/* Define to the version of this package. */
+#define PACKAGE_VERSION "1.0"
+
+/* Define to 1 if you have the ANSI C header files. */
+#define STDC_HEADERS 1
+
+/* Version number of package */
+#define VERSION "1.0"
+
+/* Define to empty if `const' does not conform to ANSI C. */
+/* #undef const */
+
+/* Define to `unsigned int' if <sys/types.h> does not define. */
+/* #undef size_t */