This page provides an overview of the kinds of things that XTide can do. How to do them will be explained in the next section.
Graph mode gives you a plot of the water level (or water velocity, in the case of currents) versus time. The times of high and low tide (or max flood and max ebb) are printed across the top. For currents, the times of slack water are printed across the bottom as shown below. Sunrise and sunset are denoted with different background colors. A + mark on the graph indicates the conditions at the time that the graph was generated.
Clock mode is similar to graph mode, but the captions are different and the window is automatically updated once a minute to show the latest conditions. The location name is replaced by the current time, the next high tide is centered at the top and the next low tide is centered at the bottom. Dates are replaced with "High Tide" and "Low Tide" captions. In the case of currents you won't get slack water.
If you iconify a
tide clock, you will get a small "classic analog" tide clock that
gives a vague idea of where you are in the tide cycle. The icon will
try to update once a minute, but this does not work under some window
managers.
Plain mode is just a plain old text listing of tide events. You get more precise heights, sunrise, and sunset times than with graph mode, and you also get moon phases which do not appear in the graph.
Washington, D.C. 38.8717° N, 77.0200° W 1998-05-31 1:02 PM EDT 3.00 feet High Tide 1998-05-31 8:24 PM EDT 0.05 feet Low Tide 1998-05-31 8:26 PM EDT Sunset 1998-06-01 1:58 AM EDT 2.82 feet High Tide 1998-06-01 5:44 AM EDT Sunrise 1998-06-01 8:37 AM EDT 0.38 feet Low Tide 1998-06-01 2:03 PM EDT 2.85 feet High Tide 1998-06-01 8:27 PM EDT Sunset 1998-06-01 9:11 PM EDT 0.15 feet Low Tide 1998-06-01 9:44 PM EDT First Quarter 1998-06-02 2:56 AM EDT 2.82 feet High Tide
Calendar mode basically just formats the output of plain mode into a calendar as shown below. This mode is not available from the interactive client.
February 1998 | ||||||
---|---|---|---|---|---|---|
Sun 1 | Mon 2 | Tue 3 | Wed 4 | Thu 5 | Fri 6 | Sat 7 |
High Tide 12.54 ft 1:19 AM EST Sunrise 6:51 AM EST Low Tide -0.86 ft 7:30 AM EST High Tide 12.47 ft 1:41 PM EST Sunset 4:42 PM EST Low Tide -1.15 ft 8:00 PM EST | High Tide 12.40 ft 2:12 AM EST Sunrise 6:50 AM EST Low Tide -0.56 ft 8:26 AM EST High Tide 11.85 ft 2:37 PM EST Sunset 4:43 PM EST Low Tide -0.62 ft 8:55 PM EST | High Tide 12.12 ft 3:08 AM EST Sunrise 6:49 AM EST Low Tide -0.18 ft 9:28 AM EST High Tide 11.20 ft 3:40 PM EST Sunset 4:44 PM EST First Quarter 5:55 PM EST Low Tide -0.06 ft 9:54 PM EST | High Tide 11.80 ft 4:09 AM EST Sunrise 6:47 AM EST Low Tide 0.13 ft 10:35 AM EST Sunset 4:46 PM EST High Tide 10.67 ft 4:47 PM EST Low Tide 0.42 ft 10:59 PM EST | High Tide 11.56 ft 5:14 AM EST Sunrise 6:46 AM EST Low Tide 0.26 ft 11:45 AM EST Sunset 4:47 PM EST High Tide 10.38 ft 5:57 PM EST | Low Tide 0.70 ft 12:05 AM EST High Tide 11.47 ft 6:21 AM EST Sunrise 6:45 AM EST Low Tide 0.19 ft 12:53 PM EST Sunset 4:49 PM EST High Tide 10.36 ft 7:04 PM EST | Low Tide 0.76 ft 1:09 AM EST Sunrise 6:44 AM EST High Tide 11.53 ft 7:24 AM EST Low Tide -0.03 ft 1:55 PM EST Sunset 4:50 PM EST High Tide 10.52 ft 8:05 PM EST |
Banner mode is a specialization of graph mode for output on tractor feed dot matrix or line printers that use continuous reams of paper. The graph is turned sideways and the aspect ratio is adjusted for Pica type. This mode is only available in the command line client.
San Francisco, California 37.8067° N, 122.4650° W -5******3****2****1****0****1****2****3****4*** 5 6 7 8 9 ******** **** **** **** **** **** **** **** ** ********f****f****f****f****f****f****f****f* f f f f f -6******t****t****t****t****t****t****t****t t t t t t ****************************************** **************************************** | | | | | | -7************************************| | | | | | | ***********************************+ | | | | | | | ********************************** | | | | | | | -8****************************** | | | | | | | | ****************************** | | | | | | | | ***************************** | | | | | | | | -9************************* | | | | | | | | | ************************** | | | | | | | | | ************************* | | | | | | | | | -10********************* | | | | | | | | | ************************ | | | | | | | | |1998-05-31 ************************ | | | | | | | | 10:35 AM PDT -11********************* | | | | | | | | | ************************ | | | | | | | | | ************************* | | | | | | | | | -12*********************** | | | | | | | | | *************************** | | | | | | | | | ****************************| | | | | | | | | -1*************************** | | | | | | | | ****************************** | | | | | | | | ******************************** | | | | | | | | -2*******************************| | | | | | | |
Stats mode is for finding the highest high tide and lowest low tide within some period of time. Stats mode is only available in the command line client.
Bar Harbor, Maine 44.3917° N, 68.2050° W Mathematical upper bound: 15.41 feet Mathematical lower bound: -3.99 feet Mean Sea Level: 5.71 feet Searched interval from 1998-01-01 12:00 AM EST to 1998-12-31 11:59 PM EST Max was 13.86 feet at 1998-11-05 10:56 AM EST Min was -2.28 feet at 1998-11-05 5:20 PM EST
Raw mode is for getting machine-readable output that can be fed into other Unix programs. The first column is a Unix time_t timestamp (seconds since 1970-01-01 00:00Z); the second column is tide heights in whatever units were selected for the location. The start, end, and step values can be set with command line switches. This mode is only available in the command line client.
896624777 0.180580 896628377 1.271889 896631977 3.463100 896635577 6.084148 896639177 8.402840 896642777 9.943272 896646377 10.421064 896649977 9.672793 896653577 7.856022 896657177 5.543402 896660777 3.413487 896664377 1.926805 896667977 1.371479
List mode does not provide tide predictions at all; it is simply a way to get the list of supported locations from the command line client.
Location | File | Coordinates |
---|---|---|
ABA, NAGASAKI (4278) | harmonics.japan | 32.7500° N, 129.9500° E |
ABASIRI, HOKKAIDO (0118) | harmonics.japan | 44.0167° N, 144.2830° E |
Abbapoola Creek Entrance, South Carolina | harmonics | 32.6767° N, 80.0067° W |
Abbot Point, Australia | harmonics.admiralty | 19.8833° S, 148.0833° E |
Aberdeen, Scotland | harmonics | 57.1500° N, 2.0833° W |
Aberdeen, Washington | harmonics | 46.9683° N, 123.8533° W |
XTide can render output in four different formats: X-windows, HTML, PNG, or text. The X-windows format is implicit in the interactive client and can't be selected explicitly. The others can be selected in the non-interactive client and are invoked automatically by the the interactive and web clients (e.g., when you save output to a file).
The currently supported combinations of mode and format are as follows:
Mode Legal forms banner text calendar text, HTML clock X-windows graph text, PNG, X-windows list text, HTML plain text, X-windows raw text stats text
The HTML and PNG formats are adequately demonstrated by the examples above in the Modes section. Here is an example of graph mode using the text format:
San Francisco, California 1998-05-31 1998-05-31 1998-05-31 10:36 AM PDT 6:14 PM PDT 11:41 PM PDT 9 ft -------------------------------------------------------------------------- 8 ft -------------------------------------------------------------------------- 7 ft -------------------------------------------------------------------------- 6 ft -------------------------------------------------------------------------- 5 ft -----------------------------------********------------------------------- **************** 4 ft ----------------------------***********************-------------------**** 3 ft -------------------------******************************---------********** *** *************************************************** 2 ft*--------------------****************************************************** 1 ft***---------------********************************************************* *******+*** ************************************************************* 0 ft*************************************************************************** 1 ft*************************************************************************** ******************************************************************************* 2 ft*************************************************************************** ******************************************************************************* 7***8***9**10*11**12***1***2***3***4**5***6***7***8***9**10**11*12***1***2***3* |***|***|***|**|***|***|***|***|***|**|***|***|***|***|***|***|*|||**|***|***|*
Here is calendar mode in the text format (note that some information is truncated to fit into 80 columns):
February 1998 Sun 1 Mon 2 Tue 3 Wed 4 Thu 5 Fri 6 Sat 7 High Tide High Tide High Tide High Tide High Tide Low Tide 0 Low Tide 0 1:19 AM ES 2:12 AM ES 3:08 AM ES 4:09 AM ES 5:14 AM ES 12:05 AM E 1:09 AM ES Sunrise Sunrise Sunrise Sunrise Sunrise High Tide Sunrise 6:51 AM ES 6:50 AM ES 6:49 AM ES 6:47 AM ES 6:46 AM ES 6:21 AM ES 6:44 AM ES Low Tide - Low Tide - Low Tide - Low Tide 0 Low Tide 0 Sunrise High Tide 7:30 AM ES 8:26 AM ES 9:28 AM ES 10:35 AM E 11:45 AM E 6:45 AM ES 7:24 AM ES High Tide High Tide High Tide Sunset Sunset Low Tide 0 Low Tide - 1:41 PM ES 2:37 PM ES 3:40 PM ES 4:46 PM ES 4:47 PM ES 12:53 PM E 1:55 PM ES Sunset Sunset Sunset High Tide High Tide Sunset Sunset 4:42 PM ES 4:43 PM ES 4:44 PM ES 4:47 PM ES 5:57 PM ES 4:49 PM ES 4:50 PM ES Low Tide - Low Tide - First Quar Low Tide 0 High Tide High Tide 8:00 PM ES 8:55 PM ES 5:55 PM ES 10:59 PM E 7:04 PM ES 8:05 PM ES Low Tide - 9:54 PM ES