From: oetiker <oetiker@a5681a0c-68f1-0310-ab6d-d61299d08faa>
Date: Mon, 11 Jun 2007 19:45:42 +0000 (+0000)
Subject: added TRENDNAN function -- Timo Stripf
X-Git-Url: https://git.verplant.org/?a=commitdiff_plain;h=5b16d46cb37b99d50005603382c7b0fa11ff4347;p=rrdtool.git

added TRENDNAN function -- Timo Stripf


git-svn-id: svn://svn.oetiker.ch/rrdtool/trunk/program@1115 a5681a0c-68f1-0310-ab6d-d61299d08faa
---

diff --git a/doc/rrdgraph_rpn.pod b/doc/rrdgraph_rpn.pod
index b2a84dd..cf62c08 100644
--- a/doc/rrdgraph_rpn.pod
+++ b/doc/rrdgraph_rpn.pod
@@ -150,7 +150,7 @@ average, ignoring all UNKNOWN values in the process.
 
 Example: C<CDEF:x=a,b,c,d,4,AVG>
 
-B<TREND>
+B<TREND, TRENDNAN>
 
 Create a "sliding window" average of another data series.
 
@@ -174,6 +174,12 @@ average is essentially computed as shown here:
      Value at sample (t1) will be the average between (t1-delay) and (t1)
      Value at sample (t2) will be the average between (t2-delay) and (t2)
 
+TRENDNAN is - in contrast to TREND - NAN-safe. If you use TREND and one 
+source value is NAN the complete sliding window is affected. The TRENDNAN 
+operation ignores all NAN-values in a sliding window and computes the 
+average of the remaining values.
+
+
 =item Special values
 
 B<UNKN>
diff --git a/src/rrd_rpncalc.c b/src/rrd_rpncalc.c
index 9078b30..717ad42 100644
--- a/src/rrd_rpncalc.c
+++ b/src/rrd_rpncalc.c
@@ -172,6 +172,7 @@ void rpn_compact2str(
             add_op(OP_SORT, SORT)
             add_op(OP_REV, REV)
             add_op(OP_TREND, TREND)
+            add_op(OP_TRENDNAN, TRENDNAN)
             add_op(OP_RAD2DEG, RAD2DEG)
             add_op(OP_DEG2RAD, DEG2RAD)
             add_op(OP_AVG, AVG)
@@ -364,6 +365,7 @@ rpnp_t   *rpn_parse(
             match_op(OP_SORT, SORT)
             match_op(OP_REV, REV)
             match_op(OP_TREND, TREND)
+            match_op(OP_TRENDNAN, TRENDNAN)
             match_op(OP_RAD2DEG, RAD2DEG)
             match_op(OP_DEG2RAD, DEG2RAD)
             match_op(OP_AVG, AVG)
@@ -757,6 +759,7 @@ short rpn_calc(
             }
             break;
         case OP_TREND:
+		case OP_TRENDNAN:
             stackunderflow(1);
             if ((rpi < 2) || (rpnp[rpi - 2].op != OP_VARIABLE)) {
                 rrd_set_error("malformed trend arguments");
@@ -766,16 +769,23 @@ short rpn_calc(
                 time_t    step = (time_t) rpnp[rpi - 2].step;
 
                 if (output_idx > (int) ceil((float) dur / (float) step)) {
-                    double    accum = 0.0;
-                    int       i = 0;
-
-                    do {
-                        accum +=
-                            rpnp[rpi - 2].data[rpnp[rpi - 2].ds_cnt * i--];
-                        dur -= step;
-                    } while (dur > 0);
-
-                    rpnstack->s[--stptr] = (accum / -i);
+					int 	ignorenan = (rpnp[rpi].op == OP_TREND);
+					double 	accum = 0.0;
+					int 	i = 0;
+					int 	count = 0;
+
+					do {
+			 			double val = 
+							rpnp[rpi - 2].data[rpnp[rpi - 2].ds_cnt * i--];
+						if (ignorenan || !isnan(val)) {
+							accum += val;
+							++count;
+			 			}
+				
+						dur -= step;
+					} while (dur > 0);
+			
+					rpnstack -> s[--stptr] = (count == 0) ? DNAN : (accum / count);
                 } else
                     rpnstack->s[--stptr] = DNAN;
             }
diff --git a/src/rrd_rpncalc.h b/src/rrd_rpncalc.h
index cc75136..5477931 100644
--- a/src/rrd_rpncalc.h
+++ b/src/rrd_rpncalc.h
@@ -16,7 +16,7 @@ enum op_en { OP_NUMBER = 0, OP_VARIABLE, OP_INF, OP_PREV, OP_NEGINF,
     OP_COS, OP_LOG, OP_EXP, OP_LT, OP_LE, OP_GT, OP_GE, OP_EQ, OP_IF,
     OP_MIN, OP_MAX, OP_LIMIT, OP_FLOOR, OP_CEIL,
     OP_UN, OP_END, OP_LTIME, OP_NE, OP_ISINF, OP_PREV_OTHER, OP_COUNT,
-    OP_ATAN, OP_SQRT, OP_SORT, OP_REV, OP_TREND,
+    OP_ATAN, OP_SQRT, OP_SORT, OP_REV, OP_TREND, OP_TRENDNAN,
     OP_ATAN2, OP_RAD2DEG, OP_DEG2RAD,
     OP_AVG, OP_ABS
 };