math: quantile estimator using P-Squared algorithm.

* Makefile (psquare.o): New object file.

* arith.c (psq_ops): New static structure.
(quant_fun): New static function.
(quantile): New function.
(arith_init): Register quantile intrinsic.

* arith.h (quantile): Declared.

* psquare.c, psquare.h: New files.

* tests/016/arith.tl: New tests.

* txr.1: Documented.

* stdlib/doc-syms.tl: Updated.

1 files changed, 2 insertions, 0 deletions

diff --git a/arith.h b/arith.h
index 1651853a..21288519 100644
--- a/arith.h
+++ b/arith.h
@@ -61,6 +61,8 @@ val digits(val n, val base);
 val poly(val x, val seq);
 val rpoly(val x, val seq);
 
+val quantile(val pv, val chsize_in, val rate_in);
+
 NORETURN void do_mp_error(val self, mp_err code);
 void arith_init(void);
 void arith_compat_fixup(int compat_ver);