X-Git-Url: https://git.octo.it/?a=blobdiff_plain;f=doc%2Frrdgraph_graph.pod;h=f40877cbae03d70ddd22b756f3f0054cf6697c07;hb=7bd35b8d099910071a57c66687f6ef79c5df9a5c;hp=eed76105926300dd6987457d050af43d1032f880;hpb=89b4e542ae2e10695233c8a4664ba8e0924bf231;p=rrdtool.git

diff --git a/doc/rrdgraph_graph.pod b/doc/rrdgraph_graph.pod
index eed7610..f40877c 100644
--- a/doc/rrdgraph_graph.pod
+++ b/doc/rrdgraph_graph.pod
@@ -1,53 +1,49 @@
+=pod
+
 =head1 NAME
 
-rrdtool graph - Round Robin Database tool grapher functions
+rrdgraph_graph - rrdtool graph command reference
+
+=head1 SYNOPSIS
+
+B<PRINT>B<:>I<vname>B<:>I<format>
+
+B<GPRINT>B<:>I<vname>B<:>I<format>
+
+B<COMMENT>B<:>I<text>
 
-WARNING: This is for version 1.1.x which is B<I<BETA>> software.
-The software may contain serious bugs. Some of the items
-described in here may not yet exist (although this should
-be mentioned) or still be in the alpha stage.  As with every
-other RRDtool release: use at your own risk.  In contrast with
-the stable version of RRDtool, this release may contain bugs
-known to the authors.  It is highly recommended that you subscribe
-to the mailing list.
+B<VRULE>B<:>I<time>B<#>I<color>[B<:>I<legend>][B<:dashes>[B<=>I<on_s>[,I<off_s>[,I<on_s>,I<off_s>]...]][B<:dash-offset=>I<offset>]]
 
-=head1 SYNOPSYS
+B<HRULE>B<:>I<value>B<#>I<color>[B<:>I<legend>][B<:dashes>[B<=>I<on_s>[,I<off_s>[,I<on_s>,I<off_s>]...]][B<:dash-offset=>I<offset>]]
 
-I<(to be) Depriciated commands>
+B<LINE>[I<width>]B<:>I<value>[B<#>I<color>][B<:>[I<legend>][B<:STACK>]][B<:dashes>[B<=>I<on_s>[,I<off_s>[,I<on_s>,I<off_s>]...]][B<:dash-offset=>I<offset>]]
 
-[B<PRINT:>I<vname>B<:>I<CF>B<:>I<format>]
-[B<GPRINT:>I<vname>B<:>I<CF>B<:>I<format>]
-[B<HRULE:>I<value>B<#>I<rrggbb>[B<:>I<legend>]]
-[B<STACK:>I<vname>[B<#>I<rrggbb>[B<:>I<legend>]]]
+B<AREA>B<:>I<value>[B<#>I<color>][B<:>[I<legend>][B<:STACK>]]
 
-I<(soon) available commands>
+B<TICK>B<:>I<vname>B<#>I<rrggbb>[I<aa>][B<:>I<fraction>[B<:>I<legend>]]
 
-[B<PRINT:>I<vname>B<:>I<format>]
-[B<GPRINT:>I<vname>B<:>I<format>]
-[B<COMMENT:>I<text>]
-[B<VRULE:>I<vname>B<#>I<rrggbb>[B<:>I<legend>]]
-[B<LINE>{B<1>|B<2>|B<3>}B<:>I<vname>[B<#>I<rrggbb>[B<:>I<legend>]]][B<:STACK>]
-[B<AREA:>I<vname>[B<#>I<rrggbb>[B<:>I<legend>]]][B<:STACK>]
+B<SHIFT>B<:>I<vname>B<:>I<offset>
 
-I<to be implemented commands>
+B<TEXTALIGN>B<:>{B<left>|B<right>|B<justified>|B<center>}
 
-[B<SHIFT:>I<vname>]
-[B<PART:>I<vname>B<#>I<rrggbb>[B<:>I<legend>]]
+B<PRINT>B<:>I<vname>B<:>I<CF>B<:>I<format> (deprecated)
+
+B<GPRINT>B<:>I<vname>B<:>I<CF>B<:>I<format> (deprecated)
+
+B<STACK>B<:>I<vname>B<#>I<color>[B<:>I<legend>] (deprecated)
 
 =head1 DESCRIPTION
 
 These instructions allow you to generate your image or report.
 If you don't use any graph elements, no graph is generated.
-Similarly no report is generated if you don't use print options.
+Similarly, no report is generated if you don't use print options.
 
 =head1 PRINT
 
-B<PRINT:>I<vname>B<:>I<CF>B<:>I<format>
+=over 4
 
-I<Depriciated. Use the new form of this command in new scripts.>
-The first form of this command is to be used with B<CDEF> I<vname>s.
 
-B<PRINT:>I<vname>B<:>I<format>
+=item B<PRINT:>I<vname>B<:>I<format>[B<:strftime>]
 
 Depending on the context, either the value component or the time
 component of a B<VDEF> is printed using I<format>. It is an error
@@ -61,185 +57,469 @@ For printing values:
 
 =over 4
 
-=item *
+=item B<%%>
 
-B<%%> just prints a literal '%' character
+just prints a literal '%' character
 
-=item *
+=item B<%#.#le>
 
-B<%#.#le> (where # is an optional number) prints like 1.2346e+04
+prints numbers like 1.2346e+04. The optional integers # denote field
+width and decimal precision.
 
-=item *
+=item B<%#.#lf>
 
-B<%#.#lf> prints like 12345.6789
+prints numbers like 12345.6789, with optional field width
+and precision.
 
-=item *
+=item B<%s>
 
-B<%s> place this after B<%le> or B<%lf>.  This will be replaced by the
+place this after B<%le>, B<%lf> or B<%lg>. This will be replaced by the
 appropriate SI magnitude unit and the value will be scaled
-accordingly (123456 -> 123.456 k)
+accordingly (123456 -> 123.456 k).
 
-=item *
+=item B<%S>
 
-B<%S> is similar to B<%s>. It does however use a previously defined
+is similar to B<%s>. It does, however, use a previously defined
 magnitude unit. If there is no such unit yet, it tries to define
-one (just like B<%s>). However, if the value is zero, the magnitude
+one (just like B<%s>) unless the value is zero, in which case the magnitude
 unit stays undefined. Thus, formatter strings using B<%S> and no B<%s>
 will all use the same magnitude unit except for zero values.
 
 =back
 
-For printing times:
+If you PRINT a VDEF value, you can also print the time associated with it by appending the string
+B<:strftime> to the format. Note that rrdtool uses the strftime function of your OSs clibrary. This means that
+the conversion specifier may vary. Check the manual page if you are uncertain. The following is a list of
+conversion specifiers usually supported across the board. 
 
 =over 4
 
-=item *
+=item B<%a>
+
+The abbreviated weekday name according to the current locale.
+
+=item B<%A>
+
+The full weekday name according to the current locale.
+
+=item B<%b>
+
+The abbreviated month name according to the current locale.
+
+=item B<%B>
+
+The full month name according to the current locale.
+
+=item B<%c>
+
+The preferred date and time representation for the current locale.
+
+=item B<%d>
+
+The day of the month as a decimal number (range 01 to 31).
+
+=item B<%H>
+
+The hour as a decimal number using a 24-hour clock (range 00 to 23).
+
+=item B<%I>
+
+The hour as a decimal number using a 12-hour clock (range 01 to 12).
+
+=item B<%j>
+
+The day of the year as a decimal number (range 001 to 366).
+
+=item B<%m>
+
+The month as a decimal number (range 01 to 12).
+
+=item B<%M>
+
+The minute as a decimal number (range 00 to 59).
+
+=item B<%p>
+
+Either `AM' or `PM' according to the given time value, or the corresponding
+strings for the current locale.  Noon is treated as `pm' and midnight as
+`am'.  Note that in many locales and `pm' notation is unsupported and in
+such cases %p will return an empty string.
+
+=item B<%S>
+
+The second as a decimal number (range 00 to 61).
 
-B<%%> just prints a literal '%' character
+=item B<%U>
 
-=item *
+The  week  number  of  the current year as a decimal number, range 00 to 53, starting with the
+first Sunday as the first day of week 01. See also %V and %W.
 
-B<%a, %A> prints abbreviated, full weekday name
+=item B<%V>
 
-=item *
+The ISO 8601:1988 week number of the current year as a decimal number, range 01 to  53,  where
+week  1 is the first week that has at least 4 days in the current year, and with Monday as the
+first day of the week. See also %U and %W.
 
-B<%b, %B> prints abbreviated, full month name
+=item B<%w>
 
-=item *
+The day of the week as a decimal, range 0 to 6, Sunday being 0.  See also %u.
 
-B<%d, %m, %y, %H, %M, %S> day,month,year,hour,minute,second all in two-digit format
+=item B<%W>
 
-=item *
+The week number of the current year as a decimal number, range 00 to  53,  starting  with  the
+first Monday as the first day of week 01.
 
-B<%Y> year in 4-digit format
+=item B<%x>
 
-=item *
+The preferred date representation for the current locale without the time.
 
-B<%I, %p>  hour (01..12), 'am' or 'pm'
+=item B<%X>
 
-=item *
+The preferred time representation for the current locale without the date.
 
-B<%j, %w> day of the week (0..6), day of the year (1..366)
+=item B<%y>
 
-=item *
+The year as a decimal number without a century (range 00 to 99).
 
-B<%c, %x, %X> date+time, date, time
+=item B<%Y>
 
-=item *
+The year as a decimal number including the century.
 
-B<%U, %W> week number of the current year with either the first sunday or
-the first monday determining the first week
+=item B<%Z>
 
-=item *
+The time zone or name or abbreviation.
 
-B<%Z> time zone
+=item B<%%>
+
+A literal `%' character.
 
 =back
 
-=head1 GRAPH
+=item B<PRINT:>I<vname>B<:>I<CF>B<:>I<format>
 
-B<GPRINT:>I<vname>B<:>I<CF>B<:>I<format>
+I<Deprecated. Use the new form of this command in new scripts.>
+The first form of this command is to be used with B<CDEF> I<vname>s.
 
-I<Depriciated. Use the new form of this command in new scripts.>
-This is the same as B<PRINT> but now it is printed inside the graph.
-See L<PRINT> for more information.
+=back
 
-B<GPRINT:>I<vname>B<:>I<format>
+=head1 GRAPH
 
-This is the same as B<PRINT> but now it is printed inside the graph.
-See L<PRINT> for more information.
+=over 4
+
+=item B<GPRINT>B<:>I<vname>B<:>I<format>
 
-B<COMMENT:>I<text>
+This is the same as C<PRINT>, but printed inside the graph.
 
-Text is printed literally in the legend section of the graph
+=item B<GPRINT>B<:>I<vname>B<:>I<CF>B<:>I<format>
 
-B<HRULE:>I<value>B<#>I<rrggbb>[B<:>I<legend>]
+I<Deprecated. Use the new form of this command in new scripts.>
+This is the same as C<PRINT>, but printed inside the graph.
 
-Draw an horizontal line at I<value>. Its color is composed from three
-hexadecimal numbers specifying the color components (00 is off, FF is
-maximum) red, green and blue.  Optionally a legend box and string is
-printed in the legend section. I<value> can be a variable from a B<VDEF>.
-It is an error to use I<vname>s from B<DEF> or B<CDEF> here.
+=item B<COMMENT>B<:>I<text>
 
-B<VRULE:>I<time>B<#>I<rrggbb>[B<:>I<legend>]
+Text is printed literally in the legend section of the graph. Note that in
+RRDtool 1.2 you have to escape colons in COMMENT text in the same way you
+have to escape them in B<*PRINT> commands by writing B<'\:'>.
+
+=item B<VRULE>B<:>I<time>B<#>I<color>[B<:>I<legend>][B<:dashes>[B<=>I<on_s>[,I<off_s>[,I<on_s>,I<off_s>]...]][B<:dash-offset=>I<offset>]]
 
 Draw a vertical line at I<time>.  Its color is composed from three
-hexadecimal numbers specifying the color components (00 is off, FF is
-maximum) red, green and blue.  Optionally a legend box and string is
+hexadecimal numbers specifying the rgb color components (00 is off, FF is
+maximum) red, green and blue followed by an optional alpha. Optionally, a legend box and string is
 printed in the legend section. I<time> may be a number or a variable
 from a B<VDEF>. It is an error to use I<vname>s from B<DEF> or B<CDEF> here.
+Dashed lines can be drawn using the B<dashes> modifier. See B<LINE> for more
+details.
+
+=item B<HRULE>B<:>I<value>B<#>I<color>[B<:>I<legend>][B<:dashes>[B<=>I<on_s>[,I<off_s>[,I<on_s>,I<off_s>]...]][B<:dash-offset=>I<offset>]]
 
-B<LINE>{B<1>|B<2>|B<3>}B<:>I<vname>[B<#>I<rrggbb>[B<:>I<legend>]][B<:STACK>]
+Draw a horizontal line at I<value>.  HRULE acts much like LINE except that
+will have no effect on the scale of the graph. If a HRULE is outside the
+graphing area it will just not be visible.
 
-Draw a line of the specified width into the graph. If the color
-is not specified, the drawing is done 'blind'.  This is useful when
-stacking something else on top of this line. Also optional is the
-legend box and string which will be printed in the legend section
-if specified. The B<vname> can be generated by B<DEF>, B<VDEF> and
-B<CDEF>.  If the optional B<STACK> modifier is used, this line is
-stacked on top of the previous element which can be a B<LINEx> or
-an B<AREA>
+=item B<LINE>[I<width>]B<:>I<value>[B<#>I<color>][B<:>[I<legend>][B<:STACK>]][B<:dashes>[B<=>I<on_s>[,I<off_s>[,I<on_s>,I<off_s>]...]][B<:dash-offset=>I<offset>]]
 
-B<AREA:>I<vname>[B<#>I<rrggbb>[B<:>I<legend>]][B<:STACK>]
+Draw a line of the specified width onto the graph. I<width> can be a
+floating point number. If the color is not specified, the drawing is done
+'invisibly'. This is useful when stacking something else on top of this
+line. Also optional is the legend box and string which will be printed in
+the legend section if specified. The B<value> can be generated by B<DEF>,
+B<VDEF>, and B<CDEF>.  If the optional B<STACK> modifier is used, this line
+is stacked on top of the previous element which can be a B<LINE> or an
+B<AREA>.
 
-See B<LINEx>, however the area between the x-axis and the line will
-also be filled.
+The B<dashes> modifier enables dashed line style. Without any further options
+a symmetric dashed line with a segment length of 5 pixels will be drawn. The
+dash pattern can be changed if the B<dashes=> parameter is followed by either
+one value or an even number (1, 2, 4, 6, ...) of positive values. Each value
+provides the length of alternate I<on_s> and I<off_s> portions of the
+stroke. The B<dash-offset> parameter specifies an I<offset> into the pattern
+at which the stroke begins.
 
-B<STACK:>I<vname>[B<#>I<rrggbb>[B<:>I<legend>]]
+When you do not specify a color, you cannot specify a legend.  Should
+you want to use STACK, use the "LINEx:<value>::STACK" form.
 
-I<Depriciated.  Use the B<STACK> modifiers on the other commands.>
-I<Note: the comments on stacking are still valid...>
-Repeats the last B<LINEx> or B<AREA> however it doesn't start at the
-x-axis but rather on top of the previous element. This implies that
-there needs to be something to stack on. An invisible B<LINEx> or
-B<AREA> is something you can stack on!
+=item B<AREA>B<:>I<value>[B<#>I<color>][B<:>[I<legend>][B<:STACK>]]
 
-Note: When you stack on something that was I<unknown>, the whole
-stack will be I<unknown> for that point in time. If the beginning
-is undefined, there's no way to end somewhere...  If you want to
-graph this stacked variable anyway you need to make sure that the
-B<LINEx> or B<AREA> it gets stacked on is not unknown. Use a CDEF
-instruction with B<IF> and B<UN> to do so.
+See B<LINE>, however the area between the x-axis and the line will
+be filled.
 
-B<THE NEXT STUFF IS NOT YET IMPLEMENTED>
+=item B<TICK>B<:>I<vname>B<#>I<rrggbb>[I<aa>][B<:>I<fraction>[B<:>I<legend>]]
 
-B<SHIFT:>I<offset in seconds>
+Plot a tick mark (a vertical line) for each value of I<vname> that is
+non-zero and not *UNKNOWN*. The I<fraction> argument specifies the length of
+the tick mark as a fraction of the y-axis; the default value is 0.1 (10% of
+the axis). Note that the color specification is not optional. The TICK marks normaly
+start at the lower edge of the graphing area. If the fraction is negative they start
+at the upper border of the graphing area.
+
+=item B<SHIFT>B<:>I<vname>B<:>I<offset>
 
 Using this command B<RRDtool> will graph the following elements
 with the specified offset.  For instance, you can specify an
-offset of S<( 7*24*60*60 = ) 604800 seconds> to "look back" one
-week. Make sure to notify the viewer you did so...
-The offset will be valid until the next B<SHIFT> command, which
-can have an offset of zero to restore normal graphing.
-As with the other grapher elements, you can specify a number or
+offset of S<( 7*24*60*60 = ) 604'800 seconds> to "look back" one
+week. Make sure to tell the viewer of your graph you did this ...
+As with the other graphing elements, you can specify a number or
 a variable here.
 
-B<RRDtool> has now support for B<pie charts>. If you include the
-B<PART> command, the canvas is extended to make room for a chart
-(or, if no other graph elements are used, the canvas is solely
-used for the pie chart). The size of the canvas is determined by
-the lesser of L<width and height|rrdgraph/item_Size>.
+=item B<TEXTALIGN>B<:>{B<left>|B<right>|B<justified>|B<center>}
+
+Labels are placed below the graph. When they overflow to the left, they wrap
+to the next line. By default, lines are justified left and right. The
+B<TEXTALIGN> function lets you change this default. This is a command and
+not an option, so that you can change the default several times in your
+argument list.
+
+=cut
+
+# This section describes the curruently defunct
+# PieChart code.
+#
+# =item B<PART>B<:>I<vname>B<#>I<rrggbb>[I<aa>][B<:>I<legend>]
+#
+# B<RRDtool> has now support for B<pie charts>. If you include the
+# B<PART> command, the canvas is extended to make room for a chart.
+# The size of the canvas is determined by the lesser of
+# L<width and height|rrdgraph/item_Size>.
+#
+# Pie parts will be concatenated, the first one will start at the
+# top and parts will be created clockwise.  The size of the part
+# is defined by the value part of the L<VDEF|rrdgraph_data/VDEF>
+# function.  It should return a number between 0 and 100, being a
+# percentage.  Providing wrong input will produce undefined results.
+#
+#
+
+=pod
+
+=item B<STACK>B<:>I<vname>B<#>I<color>[B<:>I<legend>]
+
+I<Deprecated.  Use the B<STACK> modifiers on the other commands.>
+
+=back
+
+B<Some notes on stacking>
+
+When stacking, an element is not placed above the X-axis but rather
+on top of the previous element.  There must be something to stack
+upon.
+
+You can use an B<invisible> LINE or AREA to stacked upon.
+
+An B<unknown> value makes the entire stack unknown from that moment on.
+You don't know where to begin (the unknown value) and therefore do
+not know where to end.
+
+If you want to make sure you will be displaying a certain variable,
+make sure never to stack upon the unknown value.  Use a CDEF instruction
+with B<IF> and B<UN> to do so.
+
+=head1 NOTES on legend arguments
+
+=head2 Escaping the colon
+
+A colon ':' in a I<legend> argument will mark the end of the
+legend. To enter a ':' as part of a legend, the colon must be escaped
+with a backslash '\:'.  Beware that many environments process
+backslashes themselves, so it may be necessary to write two
+backslashes in order to one being passed onto rrd_graph.
+
+=head2 String Formatting
+
+The text printed below the actual graph can be formatted by appending special
+escape characters at the end of a text. When ever such a character occurs,
+all pending text is pushed onto the graph according to the character
+specified.
+
+Valid markers are: B<\j> for justified, B<\l> for left aligned, B<\r> for
+right aligned, and B<\c> for centered. In the next section there is an
+example showing how to use centered formatting.
+
+B<\n> is a valid alias for B<\l> since incomplete parsing in earlier
+versions of rrdtool lead to this behaviour and a number of people has been using it.
+
+Normally there are two space characters inserted between every two items
+printed into the graph. The space following a string can be suppressed by
+putting a B<\g> at the end of the string. The B<\g> also ignores any space
+inside the string if it is at the very end of the string. This can be used
+in connection with B<%s> to suppress empty unit strings.
+
+ GPRINT:a:MAX:%lf%s\g
+
+A special case is COMMENT:B<\s> which inserts some additional vertical space
+before placing the next row of legends.
+
+If you are using the proportional font in your graph, you can use tab
+characters or the sequence B<\t> to line-up legend elements. Note that
+the tabs inserted are relative to the start of the current legend
+element!
 
-B<PART:>I<vname>B<#>I<rrggbb>[B<:>I<legend>]
+Since RRDtool 1.3 is using Pango for rending text, you can use Pango markup.
+Pango uses the xml B<span> tags for inline formatting instructions.:
 
-Draw a part of pie. Pie parts will be concatenated, the first one
-will start at the top and parts will be created clockwise.
-The size of the part is defined by the value part of
-the L<VDEF|rrdgraph_data/VDEF> function.  It should return
-a number between 0 and 100, being a percentage.
-Providing wrong input will produce undefined results.
+A simple example of a marked-up string might be: 
+
+ <span foreground="blue" size="x-large">Blue text</span> is <i>cool</i>!
+
+The complete list of attributes for the span tag (taken from the pango documentation):
+
+=over
+
+=item B<font_desc>
+
+A font description string, such as "Sans Italic 12"; note that any other span attributes will override this description. So if you have "Sans Italic" and also a style="normal" attribute, you will get Sans normal, not italic.
+
+=item B<font_family>
+
+A font family name
+
+=item B<face>
+
+Synonym for font_family
+
+=item B<size>
+
+Font size in 1024ths of a point, or one of the absolute sizes 'xx-small', 'x-small', 'small', 'medium', 'large', 'x-large', 'xx-large', or one of the relative sizes 'smaller' or 'larger'. If you want to specify a absolute size, it's usually easier to take advantage of the ability to specify a partial font description using 'font_desc'; you can use font_desc='12.5' rather than size='12800'.
+
+=item B<style>
+
+One of 'normal', 'oblique', 'italic'
+
+=item B<weight>
+
+One of 'ultralight', 'light', 'normal', 'bold', 'ultrabold', 'heavy', or a numeric weight
+
+=item B<variant>
+
+'normal' or 'smallcaps'
+
+=item B<stretch>
+
+One of 'ultracondensed', 'extracondensed', 'condensed', 'semicondensed', 'normal', 'semiexpanded', 'expanded', 'extraexpanded', 'ultraexpanded'
+
+=item B<foreground>
+
+An RGB color specification such as '#00FF00' or a color name such as 'red'
+
+=item B<background>
+
+An RGB color specification such as '#00FF00' or a color name such as 'red'
+
+=item B<underline>
+
+One of 'none', 'single', 'double', 'low', 'error'
+
+=item B<underline_color>
+
+The color of underlines; an RGB color specification such as '#00FF00' or a color name such as 'red'
+
+=item B<rise>
+
+Vertical displacement, in 10000ths of an em. Can be negative for subscript, positive for superscript.
+
+=item B<strikethrough>
+
+'true' or 'false' whether to strike through the text
+
+=item B<strikethrough_color>
+
+The color of strikethrough lines; an RGB color specification such as '#00FF00' or a color name such as 'red'
+
+=item B<fallback>
+
+'true' or 'false' whether to enable fallback. If disabled, then characters will only be used from the closest matching font on the system. No fallback will be done to other fonts on the system that might contain the characters in the text. Fallback is enabled by default. Most applications should not disable fallback.
+
+=item B<lang>
+
+A language code, indicating the text language
+
+=item B<letter_spacing>
+
+Inter-letter spacing in 1024ths of a point.
+
+=item B<gravity>
+
+One of 'south', 'east', 'north', 'west', 'auto'.
+
+=item B<gravity_hint>
+
+One of 'natural', 'strong', 'line'.
+
+=back
+
+To save you some typing, there are also some shortcuts:
+
+=over
+
+=item B<b>
+
+Bold
+
+=item B<big>
+
+Makes font relatively larger, equivalent to <span size="larger">
+
+=item B<i>
+
+Italic
+
+=item B<s>
+
+Strikethrough
+
+=item B<sub>
+
+Subscript
+
+=item B<sup>
+
+Superscript
+
+=item B<small>
+
+Makes font relatively smaller, equivalent to <span size="smaller">
+
+=item B<tt>
+
+Monospace font
+
+=item B<u>
+
+Underline 
+
+=back
 
 =head1 SEE ALSO
 
 L<rrdgraph> gives an overview of how B<rrdtool graph> works.
-L<rrdgraph_data> describes B<DEF>,B<CDEF> and B<VDEF> in detail,
-L<rrdgraph_rpn> describes the B<RPN> language used in the B<?DEF> statements,
+L<rrdgraph_data> describes B<DEF>,B<CDEF> and B<VDEF> in detail.
+L<rrdgraph_rpn> describes the B<RPN> language used in the B<?DEF> statements.
 L<rrdgraph_graph> page describes all of the graph and print functions.
 
 Make sure to read L<rrdgraph_examples> for tipsE<amp>tricks.
 
 =head1 AUTHOR
 
-Program by Tobias Oetiker E<lt>oetiker@ee.ethz.chE<gt>
+Program by Tobias Oetiker E<lt>tobi@oetiker.chE<gt>
 
 This manual page by Alex van den Bogaerdt E<lt>alex@ergens.op.het.netE<gt>