Table of Contents






1  Introduction

Ellipsis is a well-established particle-in-cell finite element modelling program, written by Dr. Louis Moresi, and extended into 3D by Dr. Richard Albert and Dr Frederick Dufour. This document describes the use of Ellipsis and the format of its input file. Sections within the Ellipsis input file are divided into Novice and Advanced user options. This manual is also divided in such a manner with Beginner user options outlined in chapter 3 and the Advanced user options discussed in chapter 4. General overviews of each major section within the Ellipsis input file are given within each sub-heading in the Beginner chapter.

1.1  Type Conventions

Throughout this document, the following typesetting conventions are used:

1.2  Acknowledgments

2  Overview

2.1  Axes and Model Geometry

The X axis extends horizontally toward the right, the Z axis extends vertically down, and the Y axis extends out of the screen (Only applicable when Geometry=cart3d in the input file). See Figure  1. This is a right-handed coordinate system.


Figure 1: Ellipsis coordinate axes


2.2  Data Types

There are seven main data types for values.

2.3  Units

In order to obtain computational efficiency when dealing with very large numbers, throughout Ellipsis almost all data is considered to be unit independent. That means that the units can be chosen arbitrarily, as long as consistency is maintained throughout the entire input. This is simply a process of scaling real world values into smaller numbers by using a scaling factor (see section  2.4).

2.4  Scaling and Non-Dimentionalisation

Models in Ellipsis can be scaled to be non-dimentional, that is as long as two systems are geometrically and dynamically similar, results from the one experiment can be applied to both systems no matter what the size of each system. Models are said to be geometrically similar when all lengths, areas and volumes are related by the same scaling factors and all angles between arbitrary lines are equal (see Figure  2). Models are said to be dynamically similar when the inertial, pressure, viscous and body (gravity) forces scale with the same scaling factors between the two systems.


Figure 2: Illustration of two geometrically similar structures


The ellipsis model input parameters are scaled from real world values into dimensionless values in order to minimise computation time and increase the accuracy of the solution. We use the non-dimensional scaling approach given by:
  E=N/S     (1)

where E is a dimensionless Ellipsis variable, N is the dimensional real world parameter and S is a dimensional scaling factor.

As an example, scaling from real world model length dimensions of 450km wide by 150km deep may be carried out using a length scaling factor (SL) of 1.5 x 105 m resulting in non-dimensional model geometry of 3 units wide by 1 unit deep.

Using a Thermal diffusivity scaling factor (Sk) of 1 x 10-6, a time scaling factor (St) can be found using:
  St=SL2/Sk     (2)

With a viscosity scaling factor (Sh) of 1 x 1021 and a gravity scaling factor (Sg) of 1 m/s2, a density scaling factor (Sr) can be found:
  Sr=
Sg SL St
Sh
    (3)

A stress scaling factor (Ss) can now be defined as:
  Ss=SrSg SL     (4)

Using a velocity scale (Su) defined by:
  Su=
SL
St
    (5)

The strain rate scaling factor (Se) is subsequently given by:
  Se=St     (6)

Temperature is scaled between non-dimensional values of 0.17 and 1 corresponding to temperatures of 273K and 1603K respectively using a temperature scale (ST) of 1603K.

Scaling factors for thermal properties heat generation (SHgen), thermal expansion coefficient (Sa) and heat flux (SQ) can be defined as:
  SHgen = SCp =
Ss
SrST
    (7)

  Sa=
1
ST
    (8)

  SQ =
SCp SrST SL
St
    (9)

3  Input Template

This section outlines most of the input variables that can used in the Ellipsis input template. The input file is plain text, consisting of a large list of token=value pairs. Blank lines are ignored, and everything following a # on a line is ignored as a comment. Values cannot be split over multiple lines. Where code from the input template is displayed below in typewriter font comments to the right describe what the variable is for, what type of value the variable expects (boolean, integer, etc.), possible options or data ranges for the variable and the default value. While this list is quite extensive there may still be variables not listed here in this manual (something that should hopefully change over time).

3.1  General

DESCRIBE=off (Boolean) Whether to describe the search for parameters. Default is off.
VERBOSE=off (Boolean) Whether to print out the input values as they are read in. Default is off.
BEGINNER=off (Boolean) Whether to be verbose when parameters are missing. Only applicable when VERBOSE=on. Default is off.
verbose=off (Boolean) Whether the code should be verbose about its behavior. Default is off.
datafile="" (String) The root name of the output file names, ie. the prefix to which all file extensions will be appended.

3.2  Advection-diffusion Parameters

minstep=1 (Integer) Minimum number of steps in model. Default is 1.
maxstep=500 (Integer) Minimum number of steps in model. Default is 1000, though this will depend on how long you want the model to run
Geometry=cart2d (String) This defines the geometry of the model. The following options are available:
cart2d - 2D Cartesian
cartpt5d - 2.5D Cartesian
cart3d - 3D Cartesian
axi - Axisymmetric
cylinder - Cylidrical
sphere - Spherical

3.3  Solver Related Matters

vel_relaxations=10 maximum number of velocity loops (default=10)
piterations=100 maximum Uzawa iteration loops (default=100)
viterations=20 number of velocity iterations before checking convergence (default=20)
Solver=multigrid multigrid or (later, conjugate gradient)
mg_cycle=1 style of multigrid cycle
1 = V cycle, 2 = W cycle, ... (default=1)
accuracy= desired accuracy of Uzawa algorithm (default=1.e-4)
delta_accuracy_factor=1.0 change in accuracy level->level (> 1 for nonN, < 1 for Newt)
0.001 < factor < 10.0 (default=0.2)
gs_under_relax=1.0 Gauss-Seidel under-relaxation (default=1.0)

3.4  Model Design

In this section the model geometry is assigned and the resolution is then set.

3.4.1  Model Geometry

Here you define the geometry of your model. There is no default for this section, though values are usually scaled to be between 0 and 5.

   
dimenx=3.0 (Real) Length of model along the X axis
dimenz=2.0 (Real) Length of model along the Z axis
dimeny=1.0 (Real) Length of model along the Y axis (only relevant for when Geometry=cart3d is selected)

3.4.2  Resolution

Resolution of models in Ellipsis is handled using a multigrid. This is where a solution is converged upon using a coarsely meshed model (top image in figure below) and this solution is used as input for a more finely gridded mesh and so on. This is a very computationally efficient method to solve for high resolution problems. As illustrated in Figure  3 at each multigrid level, each cell on the coarse mesh is divided into 4 cells on the finer mesh. For example, a level 1 coarse mesh with 4 cells will be divided into a level 2 mesh with 16 cells, a level 3 mesh with 64 cells and so on. Each of these cells are then filled with a user specified number of tracers or particles (now you understand the term particle in cell modelling and can feel comfortable bringing it up at a dinner party!). If the user has specified a tracer density of 4, there will be 16 tracers per element/cell since the value for tracer density refers to how many tracers in each axis direction. For example, a tracer density of 4 means create a matrix of 4 tracers in the X direction and 4 tracers in the Z direction (for a 2D model) resulting in a matrix of 16 tracers within the element. Thus a level 1 mesh with 4 cells will contain a total of 64 tracers, the level 2 mesh with 16 cells will contain 256 tracers, the level 3 mesh with 64 cells will contain 1024 tracers, etc.


Figure 3: Illustration of the multigrid meshing process


The resolution can then be changed in two ways, by either increasing the base mesh resolution (increasing the model resolution) or by increasing the number of multigrid levels (increasing model resolution).
# Grid Mesh and Levels
mgunitx=5 (Integer) Coarsest (base) multigrid cell dimensions (elements) along the X axis
mgunitz=3 (Integer) Multigrid cells along the Z axis. The default/minimum is 2.
levels=4 (Integer) Number of multigrid levels. The default is 1.
# Tracer setup
Tracers=on initialise tracers (default=on)
Tracer_appetite=0.5 ( size(tracer1)+size(tracer2) ) x Tracer_appetite (default=0.5)
Tracer_voids=off allow tracers to disappear (default=off)
Tracer_rect=1 number of rectangular regions of different tracer densities (default=0)
Tracer_rect_density=4 tracer density (N x N per finest element) (<=12)
Tracer_rect_x1=0 the coordinate extent of region should be same size as the model box
Tracer_rect_x2=dimenx  
Tracer_rect_z1=0
Tracer_rect_z2=dimenz

3.5  Material Properties

For each material you wish to use in you Ellipsis model you must assign numerous properties. These include (but are not limited to) the Ellipsis variables in the following sections.

3.5.1  General Properties



 
Material_1_density= density (default=1.0)
Material_1_porosity= initial porosity (default=0.0)
NB: initial porosity = 0 ensures that Bulk_visc is constant
Material_1_Bulk_visc= bulk visc ratio at initial porosity ( >1.0(2D), >2/3(3D) )
bulk visc = ratio*visc (default=-1.0=infinite)
div(v) + p/(bulk_visc-2/3*visc) = 0
Material_1_Bulk_modulus= B in dp = B*div(v)*dt (slightly compressible formulation) (default=0.0) where dp is on tracers (isotropic stress)
Material_1_reproduction=on allow tracer reproduction (default=on)
Material_1_phases=1 number of unique phases (first phase is phase 0) (default=1) then visc = [ sum(1/visc_n) ] (-1)
Material_1_T_block= (blocking) T above which phase change can occur (default=-1.e32)
Material_1_rheol_cpts= number of rheological components (at least one per phase) (default=1) then visc = [ sum(1/visc_n) ] (-1)
Material_1_Trange_min=-1.e8 temperature range to which rheology applies
Material_1_Trange_max=1.e8 (default=-1.e8,1.e8)
Material_1_rheol_phase=0 phase to which each rheology applies (start from 0) (default=0)

3.5.2  Colouring

# Colouring
Material_1_Red= RGB values for "cold" material (list one per PPM file)
Material_1_Green= ("hot" and "cold" are determined from T extremes)
Material_1_Blue=
Material_1_Opacity= opacity for "cold" material (negative=off)
Material_1_Red_hot= values for "hot" material
Material_1_Green_hot=
Material_1_Blue_hot=
Material_1_Opacity_hot=
Material_1_Red_strained= values for strained material
Material_1_Green_strained=
Material_1_Blue_strained=
Material_1_Opacity_strained=

3.5.3  Rheological Properties

# Rheological model
Material_2_rheol_T_type=1 rheological temperature-dependence model (default=2)
(1) visc=N0*exp(-T1*T) (Frank-Kamenetski)
(2) visc=N0*exp (E+Z*z)/(T1*(T+T0)) (Arrhenius) where z=depth
Material_2_viscN0= N0 in viscosity models (default=1.0)
Material_2_viscT1= T1 in viscosity models (default=1.0)
Material_2_viscT0= T0 in Arhennius viscosity model (default=0.0)
Material_2_viscZ= Z in Arrhenius viscosity model (default=0.0)
Material_2_viscE= E in Arrhenius viscosity model (default=0.0)
Material_2_viscTmax= maximum and minimum T to use in calculating viscosity
Material_2_viscTmin= (default=1.e32,0.0)
Material_2_sdepv_expt= exponent "s" in stress dependance of viscosity
 
# Stress-strain relationship
Material_2_yield_stress_minimum= minimum yield stress for plastic deformation (default=1.e-32)
Material_2_yield_stress_maximum= maximum yield stress for semi-brittle effect (default=1.e32)
Material_2_yield_stress_B0= "cohesion" B0 in above eqn (default=1.e32)
Material_2_yield_stress_Bp= "friction coefficient" Bp in above eqn (default=0.0)
Material_2_yield_stress_Ea= ratio Ea = f(0,0)/f(E0,0) (default=1.0,range=[0,1])0
Material_2_yield_stress_E0= strain weakening E0 (default=1.e32)
Material_2_yield_stress_En= exponent En in f(e), e<E0 (default=0.0)
Material_2_yield_stress_Bz= "friction coefficient" Bz in above eqn (default=0.0)
Material_2_yield_stress_Bc= tension cutoff Bc in above law (default=1.e32)
Material_2_yield_stress_Edota= ratio Edota = f(0,0)/f(0,Edot0) (default=1.0,range=[0,1])
Material_2_yield_stress_Edot0= strain rate weakening Edot0 (default=0.0)
Material_2_yield_stress_Edotn= exponent Edotn in f(e), edot<Edot0 (default=0.0)
Material_2_yield_stress_ET= T above which strain weakening is reset (default=1.e32)
Material_2_yield_stress_E0dt= time rate of strain reduction (healing)

3.5.4  Thermal Properties

   
# Thermal parameters
Material_2_therm_exp= thermal expansion coefficient (default=0.0)
Material_2_therm_diff= thermal diffusivity (default=0.0)
Material_2_Cp= isobaric heat capacity (default=1.0)
Material_2_Qt= internal heating rate by mass (default=0.0)

3.6  Assign Material Distributions

Once materials have been defined in your Ellipsis template you can assign rectangular, triangular or circular regions of a specified material type.

3.6.1  Rectangles

Material_rect= number of rectangular regions with different tracer properties (default=0)
Material_rect_property= tracer group name (propertiescolour)
Material_rect_x1= coordinates of tracer regions
Material_rect_x2= (successively overwritten if rectangles overlap)
Material_rect_z1=
Material_rect_z2=
 

3.6.2  Triangles

Material_trgl=
Material_trgl_property=
Material_trgl_x1=
Material_trgl_x2=
Material_trgl_x3=
Material_trgl_z1=
Material_trgl_z2=
Material_trgl_z3=

3.6.3  Circles

Material_circ=
Material_circ_property=
Material_circ_x=
Material_circ_z=
Material_circ_rad=

3.7  Assign Pre-Strained Region Distributions

In Ellipsis you can assign rectangular, triangular or circular regions with arbitrary strain.

3.7.1  Rectangles

3.7.2  Triangles

Strain_trgl= Number of triangular regions of arbitrary strain
Strain_trgl_x1= X coordinate of first triangle vertex
Strain_trgl_z1= Z coordinate of first triangle vertex
Strain_trgl_x2=
Strain_trgl_z2=
Strain_trgl_x3=
Strain_trgl_z3=
Strain_trgl_mag= Magnitude of strain (range=[0,1])

3.7.3  Circles

3.8  Initial Conditions

gravacc=10 gravitational acceleration (default=9.81)
 

3.8.1  Thermal conditions

toptbcval=0 bottbcval=1 initial temperature gradient (defaults=0.0,1.0)
num_perturbations=0
perturbmag= magnitude of T perturbation
perturbk= wavenumber in x direction (will get multiplied by pi)
perturbky= wavenumber in y direction

3.8.2  Temperature field distributions

Temp_rect=1 Number of rectangular temperature regions (default=0)
Temp_rect_x1= coordinates of region
Temp_rect_x2=
Temp_rect_z1=
Temp_rect_z2=
Temp_rect_hw= half-width of smoothed edge
Temp_rect_mag= magnitude of initial condition
Temp_rect_ovl= A/M/R = add/multiply/replace overlaps (in increasing coord direction)

3.8.3  Previous Conditions

previous_temperature_file="" initial temperature configuration to use
particle_input="" initial particle configuration (XDR binary)
previous_particle_data="" initial particle properties to use
possible keywords for binary_data and particle_data:
Temp = temperature
Pres, PorP = solid pressure, pore pressure
Visc = viscosity
Poro = porosity
Edot = strain rate
StrP, StrT = integrated plastic/total strain
Grsz = grain size

3.9  Boundary Conditions

3.9.1  Moving Boundaries

BCmoveX0v=1.0 Left hand boundary. Positive = extensional, negative = compressional
BCmoveX1v=1.0 Right hand boundary

3.9.2  Temperature

Temp_bc_rect= number of rectangular bc ranges (surfaces) (default=0)
Temp_bc_rect_norm= normal to plane of surface (X, Z, Y)
Temp_bc_rect_icpt= normal-axis intercept of bc plane
Temp_bc_rect_aa1= lateral coordinate extent in 1st dimension
Temp_bc_rect_aa2=
Temp_bc_rect_hw= half-width of bc smoothing edge
Temp_bc_rect_mag= magnitude of bc

3.9.3  Velocity

Velocity_z_bc_rect= number of rectangular bc ranges (surfaces) (default=0)
Velocity_z_bc_rect_norm= normal to plane of surface (X, Z, Y)
Velocity_z_bc_rect_icpt= normal-axis intercept of bc plane
Velocity_z_bc_rect_aa1= lateral coordinate extent in 1st dimension
Velocity_z_bc_rect_aa2=
Velocity_z_bc_rect_hw= half-width of bc smoothing edge
Velocity_z_bc_rect_mag= magnitude of bc

3.9.4  Other

periodicx=off wrap-around bc (2D only) (default=off)
periodic_rm_vx=off removes periodic bc up to a constant (default=off)
free_upper=off free upper surface (pseudo) (default=off)
free_lower=off free lower surface (pseudo) (default=off)
initial_isostasy=off set initial topography from stress-balance (default=off)

3.10  Output Files

Output from Ellipsis can either be textual or graphical. The use may define the number of timesteps between output of data and toggle compression of the output data files with the following lines:
 
storage_timesteps=1 data writing interval (based on average timestep) (default=50)
checkpt_timesteps=1 PPM (graphics) file writing interval (default=10)
COMPRESS=off output files compressed upon creation (default=on)
 
Various data types can be output from Ellipsis runs, including data realated to temperture, stress, strain rate and velocity.
 
datatypes="Temp,Pres,Pstn" desired nodal output variables (ascii file)
possible keywords for datatypes:
Velx, Vely, Velz = x, y, z velocity
PoVx, PoVz = x, z pore liquid velocity
Pres, PorP = (nodal) solid pressure, pore pressure
Temp = temperature, Comp = compression
Strf = stream function (2D cartesian coords only)
Pbdy = phase boundary
   
particle_data="" desired particle output variables (binary file)
possible keywords for particle_data:
Temp = temperature
Pres, PorP = solid pressure, pore pressure
Visc = viscosity
Poro = porosity
Edot = strain rate
StrP, StrT = integrated plastic/total strain
Grsz = grain size
 
averages="" horizontally averaged values for output (ascii)
possible keywords for averages:
Temp = temperature
Visc = viscosity
Poro = porosity
Velo = magnitude of velocity
Urms, Vrms, Wrms = rms of x, z, y velocities
   
timelog="" time record of large-scale averages (ascii)
possible keywords for timelog:
Nuss = Nusselt number
Vrms, Vxrm, Vyrm, Vzrm = total and directional rms velocities
Shfl, Bhfl = average surface and basal heat fluxes
Svav, Bvav = surface and basal vrms
   
observables="" surface observables (slice at z=0/zmax) (ascii)
possible keywords for observables:
Shfl, Bhfl = surface and basal heat fluxes
Vxsf, Vysf, Vzsf = surface velocities
Tpgx, Tpbx = surface and basal topography
Tpgk, Tpbk = surface and basal topography wavenumbers
Grvx, Grbx, Grtx = surface, basal, and topographical gravity signals
Grvk, Grbk, Grtk = wavenumbers of above
Geox, Gebx, Getx = surface, basal, and topographical geoid
Geok, Gebk, Getk = wavenumbers of above

3.11  Graphical Specifications of Output Files

PPM_files= number of PPM files at each output step (default=1) & first PPM file is *.ppm0, etc.
PPM_height= vertical size of output PPM file (default=256)
PPM_coloring= variable upon which to base colouring
possible choices for PPM_coloring: (default=1)
1=temperature, 2=viscosity, 3=stress=visc*edot,
4=solid pressure, 5=grainsize, 6=compression,
7=strain rate, 8=accumulated strain
9=pore pressure, 10=permeability, 13=melt production
 
PPM_coloring_autorange= automatically scale colour (default=1)
PPM_coloring_min= min value for color scale (default=0.0)
PPM_coloring_max= max value for color scale (default=1.0)
PPM_show_strain= colour according to actual strength change (default=0.0)

3.12  Profile/History Extraction

During an Ellipsis run you may specify to have certain data recorded at localised points in the model, called Sampling Tracers. To create a Sampling Tracer the user must define the number of Sampling Tracers to be included in the model, whether the sampling Tracer will be Eulerian (stay fixed to the initial grid position to which you assigned it) or Lagrangian (moves within the fixed mesh), the output file for the information to be displayed in and the initial XYZ location of the Sampling Tracer. Numerous different types of data can be recorded at individual Sampling Tracers, such as temperature, velocities and stress/strain. The type of data you which to record is designated using a numbered class system assigned to the Sampling_field variable, for example temperature corresponds to number 1 (see the code and comments below for full list of available variables).
   
Sampling_tracers= number of sampling tracers (default=0)
Sampling_lagrangian= (fixed) Eulerian=0 (Stay fixed with mesh) Lagrangian=1 (Move within mesh) (default=0)
Sampling_plot_num= PPM file in which profile is stored (default=0)
Sampling_x= initial x location (default=0.0)
Sampling_z= initial z location (default=0.0)
Sampling_y= initial z location (default=0.0)
Sampling_field= field to sample (default=0)
1=temperature, 2=x velocity, 3=z velocity
4=nodal pressure, 5=strain rate, 6=stress=visc*edot 14=depl
Sampling_dirn= profile direction (1=x, 2=z, 3=y) (default=0)
Sampling_normalize= 0=unnormalized, 1=normalized (default=0)
Sampling_plot_min= If not autoranging, then need a max/min for the scale
Sampling_plot_max= (default=1e4)
Sampling_R= RGB colour mixes for profiles scaled between 0 and 1 (255 real RGB terms) (default=0.0)
Sampling_G=
Sampling_B=

3.13  God Switches

The God Switches are simply switches which let you turn on or off certain aspects of the code which would otherwise be tedious to do so. For example to turn off the temperature dependent viscosity behaviour of the code you can simply set TDEPV=off, a task that would otherwise involve removing or commenting out all variables relating to temperature dependent viscosity for all materials.
 
TDEPV=on use temperature-dependent rheological parameters (default=on). Note: off is faster than turning all viscosity values to 1
VMAX=off use maximum viscosity (default=off)
VMIN=on use minimum viscosity (default=off)
visc_max= maximum, minimum viscosity cut-offs (no defaults)
visc_min=
SDEPV=off use stress dependence of viscosity (default=off)
GRDEPV=off use grain size dependence of viscosity (default=off)
YIELD=on yield stress parameters on/off (default=off)


4  Graphical User Interface

While the previous sections of this documentation outlined the specifics of the Ellipsis text input file, in order to allow easier use of the Ellipsis modelling software a Graphical User Interface (GUI) was designed at the University of Sydney School of Earth Sciences. The GUI is open-source, written in Java and therefore platform independent and sufficiently generic such that it could easily be adapted to other modeling codes with similar objectives. The GUI window is composed of several tabs, with each tab referencing a particular aspect of creation of an Ellipsis model.

4.1  Hardware and Software Requirements

Ellipsis GUI was implemented in Java, and so can be run on a range of different platforms without modification or recompilation, using the Java virtual machine. The system has been tested on computers running the Windows, Solaris, Linux and Macintosh operating systems. The only requirements are that the computer has version 1.4.2 or higher of Java installed, has enough memory, and has a display with a screen size large enough to allow the entire main window to be visible at one time. However, all modern computers should satisfy the necessary hardware requirements. The program has been tested on a PC which had only had 32 megabytes of memory, and which was running Windows 98, and it worked without any problems.

4.2  Visual Editor

In the Visual Editor tab of the Ellipsis GUI the model geometry and material settings are assigned. The following is an outline of each section and the model parameters that can be assigned in each.


Figure 4: Ellipsis GUI Visual Editor tab


4.2.1  Model geometry

In the main Visual Editor window the user can set the size of the box used in the Ellipsis run by assigning values (in meters) to the window dimension at the bottom of the window show in Figure  4. Using the mouse or the boxes labeled x1, x2, z1, and z2 (Figure  4), material regions can be defined by either rectangles, triangles or circles. Material regions can be edited by selecting the appropriate region from the Material Regions list in the lower right corner of the Visual Editor window.

4.2.2  Material properties

While in the Materials tab of the menu in the top left of the Visual Editor window you can set both the parameters general to all materials (using the Material Settings button) and also the rheological parameters of each material (using the Edit Rheology button).

4.2.3  Boundary Conditions

In the Boundary Conditions tab the user may assign various boundary conditions to the model, such as a fixed velocity along the left or right (or both) margins of the model, regions of thermal anomaly, heat flux conditions, localised stress/strain/veocity conditions etc.

4.2.4  Tracer setup

In the Tracers tab the user may define the density of tracers within each grid cell of the model simulation (see section  3.4.2).

4.2.5  Thermal zones

In the Thermal Zones tab the user may define regions of thermal anomaly using the GUI.

4.3  General Settings

In the General Settings tab the user can define what level of verbosity the model will run with (see section). You can also define the resolution of the base grid used for the multigrid analysis along with the total time the model may run for.


Figure 5: Ellipsis GUI General Settings tab


4.4  Initial Conditions

The user may define the gravitational acceleration and angle of acceleration in the Initial Conditions tab.

4.5  Output Settings

In the Output Settings tab the user may define numerous different types of output (both textual and graphic) they may require.


Figure 6: Ellipsis GUI Output Settings tab


4.6  Scaling Details

All parameters relating to scaling (see section  2.4) can be defined in the Scaling Details tab. The user may select between scaling model parameters or using no scaling (input template will contain values entered into the GUI with no scaling applied) via a drop down menu. Since the GUI is open source there may be numerous different scaling models available and users are encouraged to add more, however, the default model is the USIMS EluScaling model. parameters shown in the windows available for editing by the user are the five independent variables which are used to define all subsequent scaling parameters.


Figure 7: Ellipsis GUI Scaling Details tab


When an input template not created by the GUI is loaded into the GUI, the scaling will automatically be turned off since the GUI will have no knowledge of the scaling used to create the input file.

4.7  Input File Editor

The Input File Editor shows the Ellipsis input file created by the GUI. In this section the user may for instance add parameters to the Ellipsis input file not available to them in the GUI. It is also possible to alter parameters in the Ellipsis input file in the Input File Editor and have those changes reflected in the GUI (and vice versa).


This document was translated from LATEX by HEVEA.