Controls |
Fit: To zoom in so that the
loop completely fills the display, press this button. |
Zoom
Out: To zoom out in the view of the hysteresis loop,
press this button. |
Generate
Loop: To generate an entire hysteresis loop, press
this button. |
STOP:
To stop the simulation, press this button. |
Configure: To configure the details of the
simulation, press this button. |
Disorder: To change the disorder, type a
new value here. |
Changing the
field: Click a point in the loop view to change the
field to the value at that point. |
Zooming To zoom in on the hysteresis loop,
drag a box around the area you want to view. To zoom out, press the
Zoom Out button. To zoom so that the loop fills
the display, press the Fit button. |
If the light is green, the
applet is waiting for input. |
If the light is red, the
simulation is busy. |
Configuration
Menu: Many more features of the simulation can be
controlled through the configuration menu, which is accessed through
the configure button. Upon pressing this button, you will see a menu
with three choices: Hysteresis Model, Loop View, and
Lattice View. The latter two allow you to change some
properites of the display. The first allows you to control all
aspects of the model.
Under the Hysteresis Model menu, there are seven options:
|
Goal Field |
Enter numbers here to precisely control the external magnetic
field. When a number is entered, the magnetic field will be slowly
increased until it reaches the entered value. |
|
Disorder |
This sets the degree of disorder in the lattice. |
|
Dimensions |
Use this parameter to adjust the dimensionality of the lattice.
Any number of dimensions greater than or equal to two is valid.
(But higher dimensions will take much more memory, and run
much slower.
|
|
Width |
Adjust the width of the simulation. Any number of spins is
valid, but the larger the simulation, the slower it will run. |
|
Seeds Up |
This creates a single row of spins preflipped to point up. This
facilitates the seeding of the first avalanches in two dimensions,
and drastically changes the effects of the finite size of the
simultation. This option may be true or false |
|
Seeds Down |
This has the same effect as the Seeds Up option, except
that the row of preflipped spins points down. The two options can
be used simultaneously. |
|
Lorenzian |
When this option is false, the simulation uses a
gaussian distribution of random fields. When this option is
true, the simulation uses a Lorenzian distribution of
random fields. Because the Lorenzian distribution decays much more
slowly than the gaussian distribution, there are many more spins
with large local fields to seed the early avalanches. Right now, it
is necessary to zoom in on the hysteresis loop when using the
lorenzian distribution, because the interesting behavior occurs in
only a small fraction of the range of fields. |
|