Quirks to be aware of
- Graphs actually begin a little bit earlier than the nominal start
time so that the specified start will appear immediately to the right
of the labels for the depth axis instead of being obscured by
- The effective end time for graph and clock modes is entirely determined by
the start time, the width, and the aspect. If an end time is also
specified by the user, it is ignored.
- XTide uses shorter descriptions for the tide events listed across
the bottom caption line in tide graphs whenever the descriptions get
to be longer than the timestamps. Consequently, changing the
time format setting to something more concise causes the descriptions
to get shorter too, which is what you want. However, this
behavior can result in cosmetic inconsistencies; e.g., with default
settings, "Mark Rising" is matched by "Mark" instead of "Mark
Falling," because the one additional letter puts it over.
- The –o command line switch causes output to be appended to the
specified file instead of overwriting it as is the generally accepted
- While XTide-specific command-line arguments can be concatenated
with their switches or not, the arguments to standard X11 switches
sometimes must be separate to work. Affected switches include
–display, –fn, and –geometry.
- What XTide does about minimum current events at subordinate stations
might not be what you expect. See Appendix
B for details.
- RGB color specs (rgb:N/N/N) in sizes other than 24 bits
(rgb:hh/hh/hh) generally will not work.
- All timestamps have a precision of plus or minus one minute.
- XTide locates tide events to an accuracy of plus or minus one
minute. This refers only to the prediction model, not to how well the
model agrees with reality.
- URLs assigned to specific locations by the xttpd web server are
rather transient and will change whenever the harmonics files are
updated. The xttpd web space will remain internally consistent, but
hyperlinks from outside pages will be screwed.
- The time scale for stations claiming to be in UTC is not strictly
speaking UTC since it does not implement leap seconds.
- If a subordinate station has absurd offsets that cause
low tides to become higher than high tides, the upper and
lower bounds reported by stats mode may be incorrect.
- When specifying location names on the command line, multiple data sets having the same name cannot be distinguished, and it
is not deterministic which one you will get.
- XTide is untested and probably dysfunctional on any platform where
time_t is a non-integral type. It would probably still work with
- XTide assumes that the first 256 characters of every font agree with
ISO-8859-1 (except under DOS).
- Semitransparent style makes no sense in formats that don't support
opacity (text and PseudoColor X-windows).
- If the control panel is resized, dismissed, and then shown again, its buttons are missing.
Cause of bug: Don't know.
Workaround: Close the control panel using the window manager (e.g.,
hit the × in the upper right corner) and then show it again.
The control panel retains its new size but the buttons reappear.
- Some of the dialog windows cause harmless but annoying toolkit
warnings when you dismiss them.
Cause of bug: Don't understand what the toolkit grabs are doing.
Workaround: Ignore warnings.
- Line width in line graphs isn't maintained when the slope of the
graph becomes drastic.
Cause of bug: Need better algorithm for drawing line graphs.
Workaround: Set the aspect higher.
Buttons will sometimes shift out from under the mouse pointer and get
Cause of bug: (1) button moves due to changing geometry of other things
in the box, leading to (2) button shifts out from under the pointer,
which triggers (3) bug in Athena Widgets where the button release event
Workaround: As needed, click on the stuck button to un-stick it. This
problem can be prevented in the control panel by specifying a monospace
font with the –fn switch, which avoids (1). The bug is less likely in
- The analog tide clock icon flashes when it updates, and doesn't update
at all under some window managers. Alternate symptom: Tide clocks
crash the window manager at random.
Cause of bug: Window managers don't expect icons to keep changing and
aren't designed to handle it properly.
Workaround: Use a window manager that doesn't suck.
- Dialog boxes don't behave like you would expect when you hit
the Enter key. Cause of bug: Athena widgets use multi-line buffers
even for one-line fields. Workaround: Don't hit Enter.
- Syslog messages generated by xttpd have timestamps in UTC or
random time zones instead of local time, which is highly confusing in a
log that is otherwise in local time. Cause of bug: Design
defect of syslog(): Every program logs in whatever time zone it
happens to be using at the time instead of a standard zone.
XTide needs to adopt the time zone of each station to generate
predictions for it. Workaround: none.
- The location chooser depends on a station naming convention to determine
which stations are currents. If that convention is not followed, dots
may be drawn in the wrong color. Cause of bug: Design defect of
libtcd: libtcd doesn't let you know whether you are looking at a tide
station or a current station until after you load it. Workaround:
Ensure that "Current" appears in the station name if it's a current, and not
- When XTide is linked with Xaw3d or Xaw3dXft, text dialog boxes reachable
from the Options menu (save filename, mark level, aspect) and control panel
may have 2-color bitmap borders instead of gray-shaded borders. Cause
of bug: For reasons unknown, the "threeD" widget owned by
asciiTextWidget is inaccessible from the application level, preventing XTide
from setting its beNiceToColormap resource to False. Workaround:
XTide*beNiceToColormap: False to