new units=si option -- wim.heirmann elis.urgent.be

git-svn-id: svn://svn.oetiker.ch/rrdtool/branches/1.2/program@804 a5681a0c-68f1-0310-ab6d-d61299d08faa

diff --git a/CONTRIBUTORS b/CONTRIBUTORS
index edfde57..8a47341 100644 (file)
--- a/CONTRIBUTORS
+++ b/CONTRIBUTORS
@@ -62,6 +62,7 @@ Tom Crawley <Tom.Crawley with hi.riotinto.com.au> (GCC&HP configuration)
 Travis Brown <tebrown with csh.rit.edu> 
 Tuc <ttsg with ttsg.com>
 Ulrich Schilling <schilling with netz.uni-essen.de> AIX
+Wim Heirman <wim.heirman elis.ugent.be> --units=si option
 Wolfgang Schrimm <wschrimm with uni-hd.de> xport function
 Wrolf Courtney <wrolf with wrolf.net> (HP-UX)
 hendrik visage <hvisage with is.co.za>

diff --git a/doc/rrdgraph.pod b/doc/rrdgraph.pod
index da2b4e6..63f5307 100644 (file)
--- a/doc/rrdgraph.pod
+++ b/doc/rrdgraph.pod
@@ -227,6 +227,12 @@ How many digits should rrdtool assume the y-axis labels to be? You
 may have to use this option to make enough space once you start
 fideling with the y-axis labeling.
 
+[B<--units=si>]
+
+With this option y-axis values on logarithmic graphs will be scaled to 
+the appropriate units (k, M, etc.) instead of using exponential notation.
+Note that for linear graphs, SI notation is used by default.
+
 =back
 
 =item Miscellaneous

diff --git a/src/rrd_graph.c b/src/rrd_graph.c
index e922814..77a401a 100644 (file)
--- a/src/rrd_graph.c
+++ b/src/rrd_graph.c
@@ -312,14 +312,8 @@ auto_scale(
 }
 
 
-/* find SI magnitude symbol for the numbers on the y-axis*/
-void 
-si_unit(
-    image_desc_t *im   /* image description */
-)
-{
-
-    char symbol[] = {'a', /* 10e-18 Atto */ 
+static char si_symbol[] = {
+                    'a', /* 10e-18 Atto */ 
                     'f', /* 10e-15 Femto */
                     'p', /* 10e-12 Pico */
                     'n', /* 10e-9  Nano */
@@ -331,9 +325,17 @@ si_unit(
                     'G', /* 10e9   Giga */
                     'T', /* 10e12  Tera */
                     'P', /* 10e15  Peta */
-                    'E'};/* 10e18  Exa */
+                    'E', /* 10e18  Exa */
+};
+const static int si_symbcenter = 6;
+
+/* find SI magnitude symbol for the numbers on the y-axis*/
+void 
+si_unit(
+    image_desc_t *im   /* image description */
+)
+{
 
-    int   symbcenter = 6;
     double digits,viewdigits=0;  
     
     digits = floor( log( max( fabs(im->minval),fabs(im->maxval)))/log((double)im->base)); 
@@ -353,9 +355,9 @@ si_unit(
 
     im->viewfactor = im->magfact / pow((double)im->base , viewdigits);
 
-    if ( ((viewdigits+symbcenter) < sizeof(symbol)) &&
-                   ((viewdigits+symbcenter) >= 0) )
-        im->symbol = symbol[(int)viewdigits+symbcenter];
+    if ( ((viewdigits+si_symbcenter) < sizeof(si_symbol)) &&
+                   ((viewdigits+si_symbcenter) >= 0) )
+        im->symbol = si_symbol[(int)viewdigits+si_symbcenter];
     else
        im->symbol = '?';
  }
@@ -1746,8 +1748,23 @@ horizontal_log_grid(image_desc_t   *im)
                          X1+2,Y0,
                          MGRIDWIDTH, im->graph_col[GRC_MGRID],
                          im->grid_dash_on, im->grid_dash_off);
-          
-          sprintf(graph_label,"%3.0e",value * yloglab[majoridx][i]);
+
+          if (im->extra_flags & FORCE_UNITS_SI) {
+             double pvalue = value * yloglab[majoridx][i];
+             double scale = floor( log10( fabs(pvalue)) / 3);
+             pvalue /= pow(10, 3*scale);
+
+             char symbol;
+             if ( ((scale+si_symbcenter) < sizeof(si_symbol)) &&
+                  ((scale+si_symbcenter) >= 0) )
+                symbol = si_symbol[(int)scale+si_symbcenter];
+             else
+                symbol = '?';
+
+             sprintf(graph_label,"%3.0f %c", pvalue, symbol);
+          } else
+             sprintf(graph_label,"%3.0e",value * yloglab[majoridx][i]);
+
           gfx_new_text ( im->canvas,
                          X0-im->text_prop[TEXT_PROP_AXIS].size, Y0,
                          im->graph_col[GRC_FONT],
@@ -3006,6 +3023,10 @@ rrd_graph_options(int argc, char *argv[],image_desc_t *im)
     parsetime("end-24h", &start_tv);
     parsetime("now", &end_tv);
 
+    /* defines for long options without a short equivalent. should be bytes,
+       and may not collide with (the ASCII value of) short options */
+    #define LONGOPT_UNITS_SI 255
+
     while (1){
        static struct option long_options[] =
        {
@@ -3040,6 +3061,7 @@ rrd_graph_options(int argc, char *argv[],image_desc_t *im)
             {"no-gridfit", no_argument,       0,   'N'},
            {"units-exponent",required_argument, 0, 'X'},
            {"units-length",required_argument, 0, 'L'},
+            {"units",      required_argument, 0,  LONGOPT_UNITS_SI },
            {"step",       required_argument, 0,    'S'},
             {"tabwidth",   required_argument, 0,    'T'},            
            {"font-render-mode", required_argument, 0, 'R'},
@@ -3080,6 +3102,18 @@ rrd_graph_options(int argc, char *argv[],image_desc_t *im)
        case 'F':
            im->extra_flags |= FORCE_RULES_LEGEND;
            break;
+       case LONGOPT_UNITS_SI:
+           if(im->extra_flags & FORCE_UNITS) {
+               rrd_set_error("--units can only be used once!");
+               return;
+           }
+           if(strcmp(optarg,"si")==0)
+               im->extra_flags |= FORCE_UNITS_SI;
+           else {
+               rrd_set_error("invalid argument for --units: %s", optarg );
+               return;
+           }
+           break;
        case 'X':
            im->unitsexponent = atoi(optarg);
            break;

diff --git a/src/rrd_graph.h b/src/rrd_graph.h
index dca277f..e143b7b 100644 (file)
--- a/src/rrd_graph.h
+++ b/src/rrd_graph.h
@@ -16,6 +16,8 @@
 #define ONLY_GRAPH       0x20   /* use only graph */
 #define FORCE_RULES_LEGEND 0x40        /* force printing of HRULE and VRULE legend */
 
+#define FORCE_UNITS 0x80        /* mask for all FORCE_UNITS_* flags */
+#define FORCE_UNITS_SI 0x80     /* force use of SI units in Y axis (no effect in linear graph, SI instead of E in log graph) */
 
 enum tmt_en {TMT_SECOND=0,TMT_MINUTE,TMT_HOUR,TMT_DAY,
             TMT_WEEK,TMT_MONTH,TMT_YEAR};