Improve auto-scaling of gridlines and placement of x-labels when

plotted_time/pixel ratio gets smaller than 2. This significantly
improves readability of small graphs (i.e. around 400-pixels wide)
when time range plotted becomes less than 600 seconds. Before
this change you would only get few gridlines and from 1-2 to 0
labels depending on how lucky are you. Some examples of such
graphs can be found here. "o" vs. "n" prefix denotes behaviour
before and after the change respectively, and number after that
denotes full scale of x axis in seconds:

Before:

 http://sobomax.sippysoft.com/rrdtool/o660.png
 http://sobomax.sippysoft.com/rrdtool/o600.png
 http://sobomax.sippysoft.com/rrdtool/o540.png
 http://sobomax.sippysoft.com/rrdtool/o480.png
 http://sobomax.sippysoft.com/rrdtool/o420.png
 http://sobomax.sippysoft.com/rrdtool/o360.png
 http://sobomax.sippysoft.com/rrdtool/o300.png
 http://sobomax.sippysoft.com/rrdtool/o240.png
 http://sobomax.sippysoft.com/rrdtool/o180.png
 http://sobomax.sippysoft.com/rrdtool/o120.png

After:

 http://sobomax.sippysoft.com/rrdtool/n660.png
 http://sobomax.sippysoft.com/rrdtool/n600.png
 http://sobomax.sippysoft.com/rrdtool/n540.png
 http://sobomax.sippysoft.com/rrdtool/n480.png
 http://sobomax.sippysoft.com/rrdtool/n420.png
 http://sobomax.sippysoft.com/rrdtool/n360.png
 http://sobomax.sippysoft.com/rrdtool/n300.png
 http://sobomax.sippysoft.com/rrdtool/n240.png
 http://sobomax.sippysoft.com/rrdtool/n180.png
 http://sobomax.sippysoft.com/rrdtool/n120.png

diff --git a/src/rrd_graph.c b/src/rrd_graph.c
index 83693470a1a55d8721f2738f1f37adc0c0601af1..89075c498f512f9bf5d0c4c66ff660e47536321f 100644 (file)
--- a/src/rrd_graph.c
+++ b/src/rrd_graph.c
@@ -79,49 +79,53 @@ text_prop_t text_prop[] = {
 char week_fmt[128] = "Week %V";
 
 xlab_t    xlab[] = {
-    {0, 0, TMT_SECOND, 30, TMT_MINUTE, 5, TMT_MINUTE, 5, 0, "%H:%M"}
+    {0.0, 0, TMT_SECOND, 10, TMT_MINUTE, 1, TMT_MINUTE, 1, 0, "%H:%M"}
     ,
-    {2, 0, TMT_MINUTE, 1, TMT_MINUTE, 5, TMT_MINUTE, 5, 0, "%H:%M"}
+    {0.6, 0, TMT_SECOND, 20, TMT_MINUTE, 1, TMT_MINUTE, 1, 0, "%H:%M"}
     ,
-    {5, 0, TMT_MINUTE, 2, TMT_MINUTE, 10, TMT_MINUTE, 10, 0, "%H:%M"}
+    {1.0, 0, TMT_SECOND, 30, TMT_MINUTE, 2, TMT_MINUTE, 2, 0, "%H:%M"}
     ,
-    {10, 0, TMT_MINUTE, 5, TMT_MINUTE, 20, TMT_MINUTE, 20, 0, "%H:%M"}
+    {2.0, 0, TMT_MINUTE, 1, TMT_MINUTE, 5, TMT_MINUTE, 5, 0, "%H:%M"}
     ,
-    {30, 0, TMT_MINUTE, 10, TMT_HOUR, 1, TMT_HOUR, 1, 0, "%H:%M"}
+    {5.0, 0, TMT_MINUTE, 2, TMT_MINUTE, 10, TMT_MINUTE, 10, 0, "%H:%M"}
     ,
-    {60, 0, TMT_MINUTE, 30, TMT_HOUR, 2, TMT_HOUR, 2, 0, "%H:%M"}
+    {10.0, 0, TMT_MINUTE, 5, TMT_MINUTE, 20, TMT_MINUTE, 20, 0, "%H:%M"}
     ,
-    {60, 24 * 3600, TMT_MINUTE, 30, TMT_HOUR, 2, TMT_HOUR, 6, 0, "%a %H:%M"}
+    {30.0, 0, TMT_MINUTE, 10, TMT_HOUR, 1, TMT_HOUR, 1, 0, "%H:%M"}
     ,
-    {180, 0, TMT_HOUR, 1, TMT_HOUR, 6, TMT_HOUR, 6, 0, "%H:%M"}
+    {60.0, 0, TMT_MINUTE, 30, TMT_HOUR, 2, TMT_HOUR, 2, 0, "%H:%M"}
     ,
-    {180, 24 * 3600, TMT_HOUR, 1, TMT_HOUR, 6, TMT_HOUR, 12, 0, "%a %H:%M"}
+    {60.0, 24 * 3600, TMT_MINUTE, 30, TMT_HOUR, 2, TMT_HOUR, 6, 0, "%a %H:%M"}
+    ,
+    {180.0, 0, TMT_HOUR, 1, TMT_HOUR, 6, TMT_HOUR, 6, 0, "%H:%M"}
+    ,
+    {180.0, 24 * 3600, TMT_HOUR, 1, TMT_HOUR, 6, TMT_HOUR, 12, 0, "%a %H:%M"}
     ,
     /*{300,             0,   TMT_HOUR,3,    TMT_HOUR,12,   TMT_HOUR,12,    12*3600,"%a %p"},  this looks silly */
-    {600, 0, TMT_HOUR, 6, TMT_DAY, 1, TMT_DAY, 1, 24 * 3600, "%a"}
+    {600.0, 0, TMT_HOUR, 6, TMT_DAY, 1, TMT_DAY, 1, 24 * 3600, "%a"}
     ,
-    {1200, 0, TMT_HOUR, 6, TMT_DAY, 1, TMT_DAY, 1, 24 * 3600, "%d"}
+    {1200.0, 0, TMT_HOUR, 6, TMT_DAY, 1, TMT_DAY, 1, 24 * 3600, "%d"}
     ,
-    {1800, 0, TMT_HOUR, 12, TMT_DAY, 1, TMT_DAY, 2, 24 * 3600, "%a %d"}
+    {1800.0, 0, TMT_HOUR, 12, TMT_DAY, 1, TMT_DAY, 2, 24 * 3600, "%a %d"}
     ,
-    {2400, 0, TMT_HOUR, 12, TMT_DAY, 1, TMT_DAY, 2, 24 * 3600, "%a"}
+    {2400.0, 0, TMT_HOUR, 12, TMT_DAY, 1, TMT_DAY, 2, 24 * 3600, "%a"}
     ,
-    {3600, 0, TMT_DAY, 1, TMT_WEEK, 1, TMT_WEEK, 1, 7 * 24 * 3600, week_fmt}
+    {3600.0, 0, TMT_DAY, 1, TMT_WEEK, 1, TMT_WEEK, 1, 7 * 24 * 3600, week_fmt}
     ,
-    {3 * 3600, 0, TMT_WEEK, 1, TMT_MONTH, 1, TMT_WEEK, 2, 7 * 24 * 3600, week_fmt}
+    {3.0 * 3600.0, 0, TMT_WEEK, 1, TMT_MONTH, 1, TMT_WEEK, 2, 7 * 24 * 3600, week_fmt}
     ,
-    {6 * 3600, 0, TMT_MONTH, 1, TMT_MONTH, 1, TMT_MONTH, 1, 30 * 24 * 3600,
+    {6.0 * 3600.0, 0, TMT_MONTH, 1, TMT_MONTH, 1, TMT_MONTH, 1, 30 * 24 * 3600,
      "%b"}
     ,
-    {48 * 3600, 0, TMT_MONTH, 1, TMT_MONTH, 3, TMT_MONTH, 3, 30 * 24 * 3600,
+    {48.0 * 3600.0, 0, TMT_MONTH, 1, TMT_MONTH, 3, TMT_MONTH, 3, 30 * 24 * 3600,
      "%b"}
     ,
-    {315360, 0, TMT_MONTH, 3, TMT_YEAR, 1, TMT_YEAR, 1, 365 * 24 * 3600, "%Y"}
+    {315360.0, 0, TMT_MONTH, 3, TMT_YEAR, 1, TMT_YEAR, 1, 365 * 24 * 3600, "%Y"}
     ,
-    {10 * 24 * 3600, 0, TMT_YEAR, 1, TMT_YEAR, 1, TMT_YEAR, 1,
+    {(double)(10 * 24 * 3600), 0, TMT_YEAR, 1, TMT_YEAR, 1, TMT_YEAR, 1,
      365 * 24 * 3600, "%y"}
     ,
-    {-1, 0, TMT_MONTH, 0, TMT_MONTH, 0, TMT_MONTH, 0, 0, ""}
+    {-1.0, 0, TMT_MONTH, 0, TMT_MONTH, 0, TMT_MONTH, 0, 0, ""}
 };
 
 /* sensible y label intervals ...*/
@@ -2547,21 +2551,21 @@ void vertical_grid(
 {
     int       xlab_sel; /* which sort of label and grid ? */
     time_t    ti, tilab, timajor;
-    long      factor;
+    double    factor;
     char      graph_label[100];
     double    X0, Y0, Y1;   /* points for filled graph and more */
     struct tm tm;
 
     /* the type of time grid is determined by finding
        the number of seconds per pixel in the graph */
-    if (im->xlab_user.minsec == -1) {
-        factor = (im->end - im->start) / im->xsize;
+    if (im->xlab_user.minsec == -1.0) {
+        factor = (double)(im->end - im->start) / (double)im->xsize;
         xlab_sel = 0;
         while (xlab[xlab_sel + 1].minsec !=
-               -1 && xlab[xlab_sel + 1].minsec <= factor) {
+               -1.0 && xlab[xlab_sel + 1].minsec <= factor) {
             xlab_sel++;
         }               /* pick the last one */
-        while (xlab[xlab_sel - 1].minsec ==
+        while (xlab_sel > 0 && xlab[xlab_sel - 1].minsec ==
                xlab[xlab_sel].minsec
                && xlab[xlab_sel].length > (im->end - im->start)) {
             xlab_sel--;
@@ -4370,7 +4374,7 @@ void rrd_graph_init(
     im->xlab_form = NULL;
     im->with_markup = 0;
     im->ximg = 0;
-    im->xlab_user.minsec = -1;
+    im->xlab_user.minsec = -1.0;
     im->xorigin = 0;
     im->xOriginLegend = 0;
     im->xOriginLegendY = 0;
@@ -4662,7 +4666,7 @@ void rrd_graph_options(
                     rrd_set_error("unknown keyword %s", scan_ltm);
                     return;
                 }
-                im->xlab_user.minsec = 1;
+                im->xlab_user.minsec = 1.0;
                 im->xlab_user.stst = im->xlab_form ? im->xlab_form : "";
             } else {
                 rrd_set_error("invalid x-grid format");

diff --git a/src/rrd_graph.h b/src/rrd_graph.h
index bb51b5e70d9e869b92c1dd9029db3a0e8fdc8900..12ea8b524cd21e3b0c33aa9f238181a1eaf2743e 100644 (file)
--- a/src/rrd_graph.h
+++ b/src/rrd_graph.h
@@ -165,7 +165,7 @@ typedef struct vdef_t {
 } vdef_t;
 
 typedef struct xlab_t {
-    long      minsec;   /* minimum sec per pix */
+    double    minsec;   /* minimum sec per pix */
     long      length;   /* number of secs on the image */
     enum tmt_en gridtm; /* grid interval in what ? */
     long      gridst;   /* how many whats per grid */

diff --git a/src/rrd_xport.c b/src/rrd_xport.c
index 5623c597e49f2756b1de7b881a968e09c84e8e64..15cd0d2e5b323bfc7e21665effa8c87176962b60 100644 (file)
--- a/src/rrd_xport.c
+++ b/src/rrd_xport.c
@@ -530,7 +530,7 @@ int addToBuffer(stringbuffer_t * sb,char* data,size_t len) {
 int rrd_xport_format_sv(char sep, stringbuffer_t *buffer,image_desc_t *im,time_t start, time_t end, unsigned long step, unsigned long col_cnt, char **legend_v, rrd_value_t* data) {
   /* define the time format */
   char* timefmt=NULL;
-  if (im->xlab_user.minsec!=-1) { timefmt=im->xlab_user.stst; }
+  if (im->xlab_user.minsec!=-1.0) { timefmt=im->xlab_user.stst; }
 
   /* row count */
   unsigned long row_cnt=(end-start)/step;
@@ -601,7 +601,7 @@ int rrd_xport_format_xmljson(int flags,stringbuffer_t *buffer,image_desc_t *im,t
   /* unfortunatley we have to do it this way, 
      as when no --x-graph argument is given,
      then the xlab_user is not in a clean state (e.g. zero-filled) */
-  if (im->xlab_user.minsec!=-1) { timefmt=im->xlab_user.stst; }
+  if (im->xlab_user.minsec!=-1.0) { timefmt=im->xlab_user.stst; }
 
   /* row count */
   unsigned long row_cnt=(end-start)/step;
@@ -862,7 +862,7 @@ int rrd_xport_format_addprints(int flags,stringbuffer_t *buffer,image_desc_t *im
   char dbuf[1024];
   char* val;
   char* timefmt=NULL;
-  if (im->xlab_user.minsec!=-1) { timefmt=im->xlab_user.stst; }
+  if (im->xlab_user.minsec!=-1.0) { timefmt=im->xlab_user.stst; }
 
   /* define some other stuff based on flags */
   int json=0;