[gnumeric] qcauchy: move qcauchy to sf-dpq.c

[Morten Welinder <mortenw src gnome org>]

commit 5adb17f241eed006e156e03e5148c4b917f44789
Author: Morten Welinder <terra gnome org>
Date:   Fri Mar 20 15:10:28 2015 -0400

    qcauchy: move qcauchy to sf-dpq.c

 plugins/fn-r/extra.c |   27 ---------------------------
 src/sf-dpq.c         |   41 +++++++++++++++++++++++++++++++++++++++++
 src/sf-dpq.h         |    6 ++++++
 3 files changed, 47 insertions(+), 27 deletions(-)
---
diff --git a/plugins/fn-r/extra.c b/plugins/fn-r/extra.c
index 427cbcb..cd45058 100644
--- a/plugins/fn-r/extra.c
+++ b/plugins/fn-r/extra.c
@@ -6,33 +6,6 @@
 #include <sf-gamma.h>
 #include "extra.h"
 
-gnm_float
-qcauchy (gnm_float p, gnm_float location, gnm_float scale,
-        gboolean lower_tail, gboolean log_p)
-{
-       if (gnm_isnan(p) || gnm_isnan(location) || gnm_isnan(scale))
-               return p + location + scale;
-
-       if (log_p ? (p > 0) : (p < 0 || p > 1))
-               return gnm_nan;
-
-       if (scale < 0 || !gnm_finite(scale)) return gnm_nan;
-
-       if (log_p) {
-               if (p > -1)
-                       /* The "0" here is important for the p=0 case:  */
-                       lower_tail = !lower_tail, p = 0 - gnm_expm1 (p);
-               else
-                       p = gnm_exp (p);
-       }
-       if (p > 0.5) {
-               p = 1 - p;
-               lower_tail = !lower_tail;
-       }
-       if (lower_tail) scale = -scale;
-       return location + scale / gnm_tanpi (p);
-}
-
 /* ------------------------------------------------------------------------- */
 
 /* The skew-normal distribution.  */
diff --git a/src/sf-dpq.c b/src/sf-dpq.c
index c7374df..41366a3 100644
--- a/src/sf-dpq.c
+++ b/src/sf-dpq.c
@@ -476,3 +476,44 @@ qlnorm (gnm_float p, gnm_float logmean, gnm_float logsd, gboolean lower_tail, gb
 
        return gnm_exp (qnorm (p, logmean, logsd, lower_tail, log_p));
 }
+
+/* ------------------------------------------------------------------------ */
+
+/**
+ * qcauchy:
+ * @p: probability
+ * @location: center of distribution
+ * @scale: scale parameter of the distribution
+ * @lower_tail: if %TRUE, the lower tail of the distribution is considered.
+ * @log_p: if %TRUE, @p is given as log probability
+ *
+ * Returns: the observation with cumulative probability @p for the
+ * Cauchy distribution.
+ */
+
+gnm_float
+qcauchy (gnm_float p, gnm_float location, gnm_float scale,
+        gboolean lower_tail, gboolean log_p)
+{
+       if (gnm_isnan(p) || gnm_isnan(location) || gnm_isnan(scale))
+               return p + location + scale;
+
+       if (log_p ? (p > 0) : (p < 0 || p > 1))
+               return gnm_nan;
+
+       if (scale < 0 || !gnm_finite(scale)) return gnm_nan;
+
+       if (log_p) {
+               if (p > -1)
+                       /* The "0" here is important for the p=0 case:  */
+                       lower_tail = !lower_tail, p = 0 - gnm_expm1 (p);
+               else
+                       p = gnm_exp (p);
+       }
+       if (p > 0.5) {
+               p = 1 - p;
+               lower_tail = !lower_tail;
+       }
+       if (lower_tail) scale = -scale;
+       return location + scale / gnm_tanpi (p);
+}
diff --git a/src/sf-dpq.h b/src/sf-dpq.h
index 2c0348f..816e87b 100644
--- a/src/sf-dpq.h
+++ b/src/sf-dpq.h
@@ -31,5 +31,11 @@ gnm_float plnorm (gnm_float x, gnm_float logmean, gnm_float logsd, gboolean lowe
 gnm_float qlnorm (gnm_float p, gnm_float logmean, gnm_float logsd, gboolean lower_tail, gboolean log_p);
 
 /* ------------------------------------------------------------------------- */
+/* The Cauchy distribution */
+
+gnm_float qcauchy (gnm_float p, gnm_float location, gnm_float scale,
+                  gboolean lower_tail, gboolean log_p);
+
+/* ------------------------------------------------------------------------- */
 
 #endif