prose beam jimboLand waTor surfPPC

indexPretty

WaTor by James J. Lemon Graphics

©2005 All Rights Reserved.

Free Software

download WaTor v.2, mac OS 7.x-9.x PowerPC executable.

The download: It's a *.sit (Aladdin Stuffit) archive containing:

1) waTor v.2 executable (MacOS7.x-9.x)

Just expand and run, if you like it, please send an email to admin@jjlg.com.

Somewhere there exists a very simple world called WaTor, populated with three interrelated and competing species, in a seemingly endless but finite environment of open water and scattered rocky outcroppings. Plankton basks and thrives in the sunshine, converting solar energy into food for numerous small fish, which in turn are gobbled up by large, voracious sharks. The plankton provides excellent hunting ground for the sharks, who prefer a thick blanket of the stuff. Indeed the plankton attracts both fish and sharks, drawing them inexorably into mortal struggle. Fish love the plankton but every thicket potentially hides a prowling shark. There is nothing more comical than a shark bereft of its normal plankton blanket, robbed by a school of (snickering) fish. Sharks prevent a population explosion of fish, which indirectly benefits the plankton, giving the shark or its progeny a better place to hunt. Fish are caught between starvation from overgrazing their local plankton, and overpopulation which tends to attract marauding bands of sharks. The world of WaTor is not very far away; only as far as the nearest Macintosh. A modest ocean has been set up and the species are intensely competing. A well-meaning humanoid from Terra keeps "twiddling" with the population birth rate, starvation tolerance, and mixing of populations, draining and refilling the oceans, and every so often restarting an extinct population, even resetting the universal clock, freezing everything, or modifying Avogadro's number! One might think this simple system would quickly "optimize" itself and exhibit a stabilization of populations of plankton, fish and sharks. This is not so. The populations vary wildly, heading for abrupt extinction, then miraculously recovering to unprecedented levels of success, and all its problems. It remains "stable" in a very unstable way, over wide ranges of species density. Will the humanoid's settings be able to avoid sending the species into Armageddon? Is there a setting which will produce everlasting harmony? Is sharkie birth control the answer, or a new species of plankton? With your assistance as the Humanoid, we intend to run a few experiments to answer these and other questions. Ah, but first you need some training, you say? Very well. First, let's look at the view of WaTor the humanoid has at his terrestrial control center. There is a large screen, with a representation of the actual WaTor prominently displayed.

The screen consists of several subscreens, each with a particular function to perform.

Use the menu bar to Quit, select a painting species, and otherwise control the simulation and display.

The area labeled "Ocean" is a map of the actual WaTor PanGlobal Ocean which is represented as an array of cells.

A particular cell contains either:

a rock,

some water,

a piece of plankton,

a fish or

a shark.

The map has been flattened out on the display, but in reality the upper margin is seamlessly connected to the bottom margin, and the right margin is connected to the left. That is, a fish swimming upward (or rightward) off the screen will reappear at the bottom (or the left) without even noticing it.

Time is provided by the Universal Clock, during each tick (or Chronon) of which, each cell of the WaTor Ocean can perform zero or more "actions" as defined by the rules.

The populations follow a very simple set of rules, as follows:

Cell contents are exclusive, that is, a particular cell contains only one species at a time.

Unoccupied space is filled with water, which appears blue on the map.

Rocks are immobile and inert. That is, they do not move, hunt or eat anything, and do not die, but they do absorb space and break it up into more intimate sub-spaces. Rocks appear as black spaces on the map.

Plankton is immobile. It brews in the open ocean, not particularly associated with or anchored to rocks. Plankton grows by spreading or budding into adjacent empty cells. The rate at which this happens is the Plankton Breed Rate. Plankton does not die of old age, but is consumed directly only by fish. A cell space consumed by a fish is then occupied by the fish, leaving an open water cell behind. Plankton is represented by green on the map.

Fish are mobile, and consume as much plankton as possible. A fish will randomly swim in open ocean, but when presented with plankton, will always prefer to eat. If there is more than one adjacent cell containing plankton, the fish randomly selects one and devours it. It will eat even at risk of its own life, hoping all the while that any adjacent shark doesn't select it for dinner. If it hasn't eaten by the time Fish Starve Limit Chronons of time has elapsed, it will die and vanish, leaving behind only open ocean and memories. Fish are represented by yellow on the map.

For surviving fish, there's a reward. Every "Fish Breed Rate" Chronons of time, a fish can reproduce, provided, that is, that it finds itself next to at least one cell of open water. This is not difficult since the little guys are like lawn mowers, leaving behind lots of open ocean, perfect birth environment except devoid of food for babies. There is only one "sex" of fish, the hermaphroditic type, which just decides to give birth because it's old enough, and does so! No bothersome fishie flirting or fishie foreplay! Perhaps someday there will be a more sophisticated WaTor simulation which will simulate these interesting aspects of reproduction.

Sharks are mobile fish consumers. Sharks prefer plankton to open ocean, and simply push it aside while swimming and looking for a meal of nice tender ocean fish. When no fish are around the sharks just mill about, ventilating their gills. The sight of a fish sends the shark into a little "feeding frenzy", which always leaves a patch of ocean even in the middle of plankton, and one very happy hermaphroditic shark! Just like for the fish species, the sharks have a Shark Starvation Limit beyond which the shark will die and leave ocean water instead.

Every gestation cycle or Shark Breed Rate Chronons, a shark can give birth. As in fish breeding, this must be done where there is an unoccupied spot of open ocean. Wouldn't want to sacrifice any plankton! For this reason it is quite common to see a brooding, pregnant shark eat a meal in order to provide its offspring some living space. Sharks are represented by (what else?) a nice purplish red shark color on the map.

All of the species can be identified on the humanoid's map, by color and somewhat by behavior. However it is a dizzying spectacle, so in order to help bring order to this soup of existence, a number of numeric and graphic readout areas are provided the miserable humanoid to ease his Godly drudgery. They are, in no particular order:

shows the current population census statistics (See Figure 3). The inverse fields indicate increment/decrement enabled fields. Clicking the mouse when the cursor is positioned over the numeric field entry increments or decrements the count (See Figure 3a), which will take effect at the next Repopulation Event (See Breed and Starvation Panel below).

shows the current number of "open ocean" cells.

shows the current number of Rockupied cells. Clicking on the number resets the default beginning number of rocks.

shows the current number of plankton cells. Clicking on the number resets the default beginning number of plankton cells.

shows the number of plankton which were breeding in the previous chronon.

shows the current number of fish cells. Clicking on the number resets the default beginning number of fish.

shows the number of fish which ate plankton in the previous chronon.

shows the number of fish which were breeding in the previous chronon.

shows the number of fish which died of starvation in the previous chronon.

shows the current number of shark cells. Clicking on the number resets the default beginning number of sharks.

shows the number of sharks which ate fish in the previous chronon.

shows the number of sharks which were breeding in the previous chronon.

shows the number of sharks which died of starvation in the previous chronon.

The Breed and Starvation Panel shows and allows manipulation of the population control parameters and the current Time (in Chronons, modulo 10,000). Clicking the mouse when the cursor is positioned over the numeric field entry increments or decrements the parameter. (If the cursor is more to the left, this decrements, and if the cursor is more to the right, it increments.) The special field Time, when clicked, resets the time counter and initiates a Repopulation Event, where the map is cleared and the populations specified via the Main Statistics Panel are randomly redistributed. From left to right, the parameters have the following interpretations:

controls the Plankton Breed Rate in chronons, that is, the number of chronons which must elapse before a newborn plankton cell can reproduce.

controls the Fish Breed Rate in chronons, that is, the number of chronons which must elapse before a newborn fish can reproduce.

controls the Shark Breed Rate in chronons, that is, the number of chronons which must elapse before a newborn shark can reproduce.

controls the Fish Starvation Limit in chronons, that is, the number of chronons after which a fish will die without eating plankton.

controls the Shark Starvation Limit in chronons, that is, the number of chronons after which a shark will die without eating fish.

The Barchart 1 Panel shows

a) instantaneous fraction for each species, as well as the

b) positive or negative instantaneous rate of change.

Piechart displays the instantaneous fraction of the species

Stripchart 2 displays the same selected data as stripchart 3, except it is a fixed, smallish size. This way, you can have an instantaneous readout of the selected parameter and still use the long stripchart for a separate interval.

Stripchart 2 is switchable on/off with the small red rectangle in the upper left corner.

Stripchart 3 displays any selected parameter from the tabulation.

To select a different channel click on the name in the tabulation.

To see a longer stripchart, click and drag the tab in the upper right hand corner.

For a benchmark of your CPU use this number carefully.

The gauges show the birth and death activity for each species.