NAME

       xtide - Harmonic tide clock and tide predictor (interactive client)

SYNOPSIS

       xtide [-b ``YYYY-MM-DD HH:MM''] [-bc color] [-bg color] [-cb y|n] [-cc color] [-ch pixels]
       [-cw pixels] [-dc color] [-Dc color] [-df ``format-string''] [-display ``X display''] [-ec
       color]  [-el  y|n]  [-em  pSsMm] [-fc color] [-fe y|n] [-fg color] [-fn font] [-ga aspect]
       [-geometry ``±XOFF±YOFF''] [-gf font] [-gh pixels] [-gl longitude] [-gs d|l|s]  [-gt  y|n]
       [-gw  pixels]  [-hf  ``format-string'']  [-in y|n] [-l ``location name''] [-lw pixels] [-m
       a|g|k|m|p|r] [-mc color] [-Mc color] [-mf font] [-ml [-]N.NN(ft|m|kt)]  [-nc  color]  [-tc
       color] [-tf ``format-string''] [-tl y|n] [-to opacity] [-u ft|m] [-v] [-z y|n]

DESCRIPTION

       XTide  is  a  package  that  provides  tide  and  current predictions in a wide variety of
       formats. Graphs, text listings, and calendars can be generated, or a  tide  clock  can  be
       provided on your desktop.

       XTide can work with X-windows, plain text terminals, or the web. This is accomplished with
       three separate programs: the interactive interface (xtide), the non-interactive or command
       line interface (tide), and the web interface (xttpd).

       xtide  is  the  interactive  X-windows client for XTide 2.  Although in reality it accepts
       many command line options, you should not  need  to  use  them;  everything  can  be  done
       interactively.   Just run xtide and point and click your way to whatever you need.  If you
       get stuck, click on a `?' button for on-line help.

       For a complete discussion of the command line options and a detailed  explanation  of  the
       interactive     interface,     please     see     the     verbose     documentation     at
       http://www.flaterco.com/xtide/.

CONFIGURATION

       Unless a configuration file /etc/xtide.conf is supplied,  you  must  set  the  environment
       variable  HFILE_PATH to point to the harmonics files that should have been installed along
       with the xtide program.  Example:
              export HFILE_PATH=/usr/local/share/xtide/harmonics.tcd
       If a configuration file is used, the first line should consist of the colon-separated list
       of harmonics files (e.g. the HFILE_PATH line above without the "export HFILE_PATH=" part).
       The environment variable takes precedence over the configuration file.  Also, note that on
       Debian  systems  the  tidal  harmonics data file are stored in /usr/share/xtide instead of
       /usr/local/share/xtide as used above.

       If the optional World Vector Shoreline files have been installed, the path to those  files
       can  be  supplied  in  the  WVS_DIR  environment  variable  or  as  the second line of the
       configuration file.

       Set the environment variable XTIDE_DEFAULT_LOCATION to the name of your favorite place  if
       you want to skip the location-choosing step.

OPTIONS

       -b ``YYYY-MM-DD HH:MM''
              Specify  the begin (start) time for predictions using the ISO 8601 compliant format
              YYYY-MM-DD HH:MM, where hours range from 00 to 23.  The timestamp is in  the  local
              time  zone for the location, or in UTC if the -z setting is engaged.  If clock mode
              is selected or if no -b is supplied, the current time will be used.

       -bc color
              Background color of buttons (default gray80).

       -bg color
              Background color for text windows and location chooser (default white).

       -cb y|n
              Select whether or not tide clocks should be created with buttons (default n).

       -cc color
              Color of  dots  indicating  current  stations  in  the  location  chooser  (default
              rgb:00/A0/00).

       -ch pixels
              Initial height for tide clocks (default 312 pixels).

       -cw pixels
              Initial width for tide clocks (default 84 pixels).

       -dc color
              Daytime background color in tide graphs (default SkyBlue).

       -Dc color
              Color of datum line in tide graphs (default white).

       -df ``format-string''
              strftime(3) style format string for printing dates (default %Y-%m-%d).

       -display ``X display''
              Specify  the  X  display, e.g. "quake:0.0".  This overrides the DISPLAY environment
              variable.

       -ec color
              Foreground in tide graphs during outgoing tide (default SeaGreen).

       -el y|n
              Select whether or not to draw datum and middle-level lines in tide graphs  (default
              n).

              The  National  Ocean  Service (NOS) defines both Mean Sea Level (MSL) and Mean Tide
              Level (MTL) in terms of averages taken over observations.  The middle-level line is
              drawn  at the midpoint of the theoretical tidal range, which usually corresponds to
              the mathematical mean level of the predictions.  This  approximates  both  MSL  and
              MTL,  but,  strictly  speaking,  is  equivalent  to neither.  Moreover, subordinate
              station offsets may shift the actual mean  so  that  it  no  longer  falls  at  the
              midpoint  of  the  tidal  range.   The datum line is drawn at the zero level of the
              predictions, which usually corresponds to the station's benchmark, but this too can
              be rendered inaccurate by subordinate station offsets.

       -em pSsMm
              Events  to  suppress (p = phase of moon, S = sunrise, s = sunset, M = moonrise, m =
              moonset), or x to suppress none.  E.g, to suppress all sun  and  moon  events,  set
              eventmask to the value pSsMm.

       -fc color
              Foreground in tide graphs during incoming tide (default Blue).

       -fe y|n
              Select  whether  or not to prefer flat map to round globe location chooser (default
              n).

       -fg color
              Color of text and other notations (default black).

       -fn font
              Font used for button labels and verbiage in text windows (default as incoming  from
              X11 or libXaw3dXft).  See NOTES.

       -ga aspect
              Initial  aspect  for  tide  graphs and clocks (default 1.0).  This controls not the
              width or height of the window but rather the relative scaling of the X and  Y  axes
              in the plot of the tide curve.

       -geometry ``±XOFF±YOFF''
              Specify a position for the window corresponding to the first use of -l.  (Width and
              height are controlled by different settings.)

       -gf font
              Font used in graphs and clocks in interactive client  (default  "embedded").   Does
              not affect SVG-format output.  See NOTES.

       -gh pixels
              Initial height for tide graphs (default 312 pixels).

       -gl longitude
              Initial center longitude for location chooser.  Valid values are -180 -150 -120 -90
              -60 -30 0 30 60 90 120 150 and 360.  360 (the default) will pick the longitude with
              the most tide stations.

       -gs d|l|s
              Style   of   graphs   and   clocks.    Valid  values:  d  (default),  l  (line),  s
              (semitransparent).

       -gt y|n
              Select whether or not to label tenths of units in tide graphs (default n).

       -gw pixels
              Initial width for tide graphs (default 960 pixels).

       -hf ``format-string''
              strftime(3) style format string for printing hour labels on time axis (default %l).

       -in y|n
              Select whether or not to use inferred values for  some  constituents  (default  n).
              For expert use only.

       -l ``location name''
              Specify a location for tide predictions. When given to the interactive client, this
              causes it to start a tide clock for the specified location instead of  launching  a
              location chooser on startup. This is useful for starting a tide clock automatically
              when you log on. Multiple uses of -l will result in multiple tide clocks.

       -lw pixels
              Width of line in graph styles l and s (default 2.5 pixels).

       -m a|g|k|m|p|r
              Specify mode to be about, graph, clock, medium rare, plain, or raw.  The default is
              clock.

       -mc color
              Color of mark line in graphs (default red).

       -Mc color
              Color of middle-level line in tide graphs (default yellow).

       -mf font
              Monospace  font  used  for  location list, text predictions, help windows and about
              mode  text  (default   "-misc-fixed-medium-r-normal--13-100-100-100-c-70-iso8859-1"
              (without libXaw3dXft) or "LiberationMono-12" (with libXaw3dXft)).  See NOTES.

       -ml [-]N.NN(ft|m|kt)
              Specify  an  initial  mark level to be used in prediction windows launched from the
              command line.  The predictions will include the times when the tide  level  crosses
              the  mark.  The mark level also can be specified or changed using the Options menu.
              Not supported in clock mode.  Does not affect windows that are  launched  from  the
              location chooser.  Example usage: -ml -0.25ft

       -nc color
              Nighttime background color in tide graphs (default DeepSkyBlue).

       -tc color
              Color of dots indicating tide stations in the location chooser (default red).

       -tf ``format-string''
              strftime(3) style format string for printing times (default %l:%M %p %Z).

       -tl y|n
              Select whether or not to draw depth lines on top of the tide graph (default n).

       -to opacity
              Opacity of the fill in graph style s (semitransparent) (default 0.65).

       -u ft|m
              Preferred units of length (default no preference).

       -v     Print version string and exit.

       -z y|n Select whether or not to coerce all time zones to UTC (default n).

NOTES

       If  XTide  is  built with Xaw3dXft, font names given to XTide must be in fontconfig format
       (e.g.,    "Helvetica-10"),     rather     than     the     traditional     XLFD     (e.g.,
       "-*-helvetica-*-r-*-*-10-*-*-*-*-*-*-*").   Also, Xaw3dXft does not return errors if there
       are problems with a font name; it just loads a default font instead.

SEE ALSO

       tide(1), xttpd(8), http://www.flaterco.com/xtide/.