Controls for the applets

For a quick start with default values, just go to an applet and click on the "Start" button. You can experiment with varying the parameters and heuristics.

Applet 1

Applet 1 solves for the ground state of a single RFIM sample, while displaying the evolving auxiliary fields for the push-relabel algorithm.

This applet has four rows of controls:

  1. Run controls and status text. The "Pause", "Start", "Step", and "Reset" buttons are used for stopping, starting, and single stepping the algorithm and for resetting the parameters of the simulation (see below especially for a description of "Reset"). The magenta text indicates the status of the simulation.
  2. Sample parameters. Here one can set the strength of the disorder (the width of the Gaussian random fields), the length of the edges of the sample (periodic boundary conditions), and the dimensionality d of the sample (d=1, 2 or 3; a single slice of the 3D samples is displayed.)
  3. Algorithm parameters. The drop-down menu sets the order in which push-relabel steps are carried out. The interval between global updates gives the number of push-relabel steps between global updates.
  4. Display parameters. One can turn on and off the display of the excesses (the white and black regions show positive and negative excess; zero excess sites are colored by their height). The simulation can be slowed down by seeing the "Display pause" to a value greater than zero.

Detailed description of controls

Checkboxes:

(Changes to these will take effect immediately without requiring the use of the Reset button.)
Show excesses
Displays sites with positve excess as white and those with negative excess as black. Sites with zero excess are colored normally.

Show saturated bonds
Draws a black line between two adjacent cells if the bond joining them is saturated in one direction or the other.

Drop-down menu(s):

(Changes to these will take effect immediately without requiring the use of the Reset button; however, it is recommended that you Pause before making changes, as the applets tend to become unstable otherwise.)

These allow you to select which data structure the solver will use. The data structure which is used determines the order in which the algorithm moves through the active sites, which can have a large impact on the running time. Compare the FIFO queue and the stack.

Text Fields:

(Changes to these require the Reset button to take effect.)
Field strength
Represents the standard deviation of the gaussian distribution which governs the random fields of each spin. This is the parameter Δ.

Global update freqency
Refers to the number of push-relabel cycles between global updates.

Dimensions and side length
Self-explanatory. Currently, applet 1 supports 1 and higher dimensions, while applet 2 supports 2 dimensions and above. For dimensions higher than 2, the applet displays a single two-dimensional face of the model.

Delay time
The applet will pause for the indicated number of milliseconds after each cycle. This is useful for smaller simulations or faster machines.

Buttons:

Start
Starts the applet solving the current settings configuation, or continues it if paused.

Step
Executes one push-relabel step and pauses. This is also useful for, e.g., changing the checkbox options once the solve is finished.

Pause
Pauses execution of the solve run.

Reset
This button implements changes made to the various text fields. It examines what changes have been made to the text fields and makes alterations to the appropriate variables. It also restarts the solve process and creates a new base Net to start from if required.

The way this works is as follows: