DEMO_febio_0034_sphere_cone_slide_body_force
Below is a demonstration for:
- Building geometry for a spherical blob with tetrahedral elements which is being aspirated into a tube. This demo consists off:
- Defining the boundary conditions
- Coding the febio structure
- Running the model
- Importing and visualizing the displacement results
Contents
Keywords
- febio_spec version 3.0
- febio, FEBio
- indentation
- contact, sliding, friction
- rigid body constraints
- tetrahedral elements, tet4
- triangular elements, tri3
- shell elements
- sphere
- static, solid
- hyperelastic, Ogden
- displacement logfile
- stress logfile
clear; close all; clc;
Plot settings
fontSize=15; faceAlpha1=0.8; faceAlpha2=0.3; markerSize=40; lineWidth=3; cMap=[1 0.5 0.4; 0.9 0.3 0.27; 0.8 0.2 0.18; 0.7 0.1 0.09; 0.6 0 0; 0.5 0 0; 0.4 0 0;]; [cMap]=resampleColormap(cMap,250);
Control parameters
% Path names defaultFolder = fileparts(fileparts(mfilename('fullpath'))); savePath=fullfile(defaultFolder,'data','temp'); % Defining file names febioFebFileNamePart='tempModel'; febioFebFileName=fullfile(savePath,[febioFebFileNamePart,'.feb']); %FEB file name febioLogFileName=[febioFebFileNamePart,'.txt']; %FEBio log file name febioLogFileName_disp=[febioFebFileNamePart,'_disp_out.txt']; %Log file name for exporting displacement febioLogFileName_strainEnergy=[febioFebFileNamePart,'_energy_out.txt']; %Log file name for exporting strain energy density % Sphere parameters sphereRadius=3;% pointSpacing=0.2; % Ground plate parameters tubeRadius=sphereRadius.*[1 0.1]; tubeAngle=3*(pi/180); tubeLength=abs(diff(tubeRadius))/tan(tubeAngle); % Material parameter set c1=1e-3; %Shear-modulus-like parameter MPa m1=2; %Material parameter setting degree of non-linearity k_factor=10; %Bulk modulus factor k=c1*k_factor; %Bulk modulus materialDensity=1e-9; %Density % FEA control settings analysisType='dynamic'; timeTotal=1; %Analysis time numTimeSteps=60; %Number of time steps desired step_size=timeTotal/numTimeSteps; dtmin=(timeTotal/numTimeSteps)/100; %Minimum time step size dtmax=timeTotal/20; %Maximum time step size max_refs=25; %Max reforms max_ups=0; %Set to zero to use full-Newton iterations opt_iter=15; %Optimum number of iterations max_retries=25; %Maximum number of retires symmetric_stiffness=0; min_residual=1e-20; %Contact parameters contactPenalty=15; laugon=0; minaug=1; maxaug=10; fric_coeff=0.1; %Specifying load sphereVolume=4/3*(pi*sphereRadius^3); %Sphere Volume in mm^3 sphereMass=sphereVolume.*materialDensity; %Sphere mass in tone sphereSectionArea=pi*sphereRadius^2; bodyLoadMagnitude=(9.81*1000)*5; %Body force magnitude forceBodyLoad=sphereMass.*bodyLoadMagnitude; stressBodyLoad=forceBodyLoad/sphereSectionArea;
Creating model geometry and mesh
%Control settings cPar.sphereRadius=sphereRadius; cPar.coreRadius=sphereRadius.*0.75; cPar.numElementsCore=ceil((sphereRadius/2)/pointSpacing); cPar.numElementsMantel=ceil((sphereRadius-cPar.coreRadius)/(2*pointSpacing)); cPar.makeHollow=0; cPar.outputStructType=2; cPar.cParSmooth.n=25; %Creating sphere [meshOutput]=hexMeshSphere(cPar); % Access model element and patch data Fb_blob=meshOutput.facesBoundary; Cb_blob=meshOutput.boundaryMarker; V_blob=meshOutput.nodes; E_blob=meshOutput.elements;
Visualize blob mesh
hFig=cFigure; subplot(1,2,1); hold on; gpatch(Fb_blob,V_blob,Cb_blob,'k',0.8); patchNormPlot(Fb_blob,V_blob); axisGeom(gca,fontSize); colormap(gjet); icolorbar; camlight headlight; hs=subplot(1,2,2); hold on; title('Cut view of solid mesh','FontSize',fontSize); cPar.hFig=[hFig hs]; gpatch(Fb_blob,V_blob,'kw','none',0.25); meshView(meshOutput,cPar); axisGeom(gca,fontSize); drawnow;
Creating tube model
pointSpacingBlob=max(patchEdgeLengths(Fb_blob,V_blob)); pointSpacingTube=pointSpacingBlob/2; rEnd=sphereRadius+(sphereRadius.*((sphereRadius-tubeRadius(2))/tubeLength)); V_curve_tube=[sphereRadius rEnd 0; -tubeLength tubeRadius(2) 0;]; nResample=ceil(max(pathLength(V_curve_tube))./pointSpacingTube); V_curve_tube=evenlySampleCurve(V_curve_tube,nResample,'pchip',0); cPar.closeLoopOpt=1; cPar.numSteps=[]; %If empty the number of steps is derived from point spacing of input curve cPar.w=[1 0 0]; [F_tube,V_tube]=polyRevolve(V_curve_tube,cPar); center_of_mass_tube=mean(V_tube,1);
Join model node sets
V=[V_blob; V_tube; ]; F_tube=F_tube+size(V_blob,1);
Visualizing model
cFigure; hold on; gtitle('Model components',fontSize); hl(1)=gpatch(Fb_blob,V,'rw','k',0.8); hl(2)=gpatch(F_tube,V,'kw','k',0.5); legend(hl,{'Blob','Tube'}); clear hl; axisGeom(gca,fontSize); camlight headlight; drawnow;
Get contact surfaces
F_contact_secondary=Fb_blob;
Visualize contact surfaces
cFigure; hold on; title('Tube blob contact pair','fontsize',fontSize); hl(1)=gpatch(F_tube,V,'rw','k',0.8); patchNormPlot(F_tube,V); hl(2)=gpatch(F_contact_secondary,V,'kw','k',0.5); patchNormPlot(F_contact_secondary,V); legend(hl,{'Master','Slave'}); clear hl; axisGeom(gca,fontSize); camlight headlight; drawnow;
Defining the FEBio input structure
See also febioStructTemplate and febioStruct2xml and the FEBio user manual.
%Get a template with default settings [febio_spec]=febioStructTemplate; %febio_spec version febio_spec.ATTR.version='3.0'; %Module section febio_spec.Module.ATTR.type='solid'; %Control section febio_spec.Control.analysis=analysisType; febio_spec.Control.time_steps=numTimeSteps; febio_spec.Control.step_size=timeTotal/numTimeSteps; febio_spec.Control.solver.max_refs=max_refs; febio_spec.Control.solver.max_ups=max_ups; febio_spec.Control.solver.symmetric_stiffness=symmetric_stiffness; febio_spec.Control.time_stepper.dtmin=dtmin; febio_spec.Control.time_stepper.dtmax=dtmax; febio_spec.Control.time_stepper.max_retries=max_retries; febio_spec.Control.time_stepper.opt_iter=opt_iter; %Material section materialName1='Material1'; febio_spec.Material.material{1}.ATTR.name=materialName1; febio_spec.Material.material{1}.ATTR.type='Ogden unconstrained'; febio_spec.Material.material{1}.ATTR.id=1; febio_spec.Material.material{1}.c1=c1; febio_spec.Material.material{1}.m1=m1; febio_spec.Material.material{1}.c2=c1; febio_spec.Material.material{1}.m2=-m1; febio_spec.Material.material{1}.cp=k; febio_spec.Material.material{1}.density=materialDensity; materialName2='Material2'; febio_spec.Material.material{2}.ATTR.name=materialName2; febio_spec.Material.material{2}.ATTR.type='rigid body'; febio_spec.Material.material{2}.ATTR.id=2; febio_spec.Material.material{2}.density=1; febio_spec.Material.material{2}.center_of_mass=center_of_mass_tube; %Mesh section % -> Nodes febio_spec.Mesh.Nodes{1}.ATTR.name='nodeSet_all'; %The node set name febio_spec.Mesh.Nodes{1}.node.ATTR.id=(1:size(V,1))'; %The node id's febio_spec.Mesh.Nodes{1}.node.VAL=V; %The nodel coordinates % -> Elements partName1='Part1'; febio_spec.Mesh.Elements{1}.ATTR.name=partName1; %Name of this part febio_spec.Mesh.Elements{1}.ATTR.type='hex8'; %Element type febio_spec.Mesh.Elements{1}.elem.ATTR.id=(1:1:size(E_blob,1))'; %Element id's febio_spec.Mesh.Elements{1}.elem.VAL=E_blob; %The element matrix partName2='Part2'; febio_spec.Mesh.Elements{2}.ATTR.name=partName2; %Name of this part febio_spec.Mesh.Elements{2}.ATTR.type='quad4'; %Element type febio_spec.Mesh.Elements{2}.elem.ATTR.id=size(E_blob,1)+(1:1:size(F_tube,1))'; %Element id's febio_spec.Mesh.Elements{2}.elem.VAL=F_tube; %The element matrix % -> Surfaces surfaceName1='contactSurface1'; febio_spec.Mesh.Surface{1}.ATTR.name=surfaceName1; febio_spec.Mesh.Surface{1}.quad4.ATTR.id=(1:1:size(F_tube,1))'; febio_spec.Mesh.Surface{1}.quad4.VAL=F_tube; surfaceName2='contactSurface2'; febio_spec.Mesh.Surface{2}.ATTR.name=surfaceName2; febio_spec.Mesh.Surface{2}.quad4.ATTR.id=(1:1:size(F_contact_secondary,1))'; febio_spec.Mesh.Surface{2}.quad4.VAL=F_contact_secondary; % -> Surface pairs contactPairName='Contact1'; febio_spec.Mesh.SurfacePair{1}.ATTR.name=contactPairName; febio_spec.Mesh.SurfacePair{1}.primary=surfaceName1; febio_spec.Mesh.SurfacePair{1}.secondary=surfaceName2; %MeshDomains section febio_spec.MeshDomains.SolidDomain.ATTR.name=partName1; febio_spec.MeshDomains.SolidDomain.ATTR.mat=materialName1; febio_spec.MeshDomains.ShellDomain.ATTR.name=partName2; febio_spec.MeshDomains.ShellDomain.ATTR.mat=materialName2; %Loads section % -> Body load febio_spec.Loads.body_load.ATTR.type='const'; febio_spec.Loads.body_load.x.ATTR.lc=1; febio_spec.Loads.body_load.x.VAL=bodyLoadMagnitude; %Rigid section % -> Prescribed rigid body boundary conditions febio_spec.Rigid.rigid_constraint{1}.ATTR.name='RigidFix_1'; febio_spec.Rigid.rigid_constraint{1}.ATTR.type='fix'; febio_spec.Rigid.rigid_constraint{1}.rb=2; febio_spec.Rigid.rigid_constraint{1}.dofs='Rx,Ry,Rz,Ru,Rv,Rw'; %Contact section febio_spec.Contact.contact{1}.ATTR.type='sliding-elastic'; febio_spec.Contact.contact{1}.ATTR.surface_pair=contactPairName; febio_spec.Contact.contact{1}.two_pass=1; febio_spec.Contact.contact{1}.laugon=laugon; febio_spec.Contact.contact{1}.tolerance=0.2; febio_spec.Contact.contact{1}.gaptol=0; febio_spec.Contact.contact{1}.minaug=minaug; febio_spec.Contact.contact{1}.maxaug=maxaug; febio_spec.Contact.contact{1}.search_tol=0.01; febio_spec.Contact.contact{1}.search_radius=0.1; febio_spec.Contact.contact{1}.symmetric_stiffness=0; febio_spec.Contact.contact{1}.auto_penalty=1; febio_spec.Contact.contact{1}.penalty=contactPenalty; febio_spec.Contact.contact{1}.fric_coeff=fric_coeff; %LoadData section % -> load_controller febio_spec.LoadData.load_controller{1}.ATTR.id=1; febio_spec.LoadData.load_controller{1}.ATTR.type='loadcurve'; febio_spec.LoadData.load_controller{1}.interpolate='LINEAR'; febio_spec.LoadData.load_controller{1}.points.point.VAL=[0 0; 1 1]; %Output section % -> log file febio_spec.Output.logfile.ATTR.file=febioLogFileName; febio_spec.Output.logfile.node_data{1}.ATTR.file=febioLogFileName_disp; febio_spec.Output.logfile.node_data{1}.ATTR.data='ux;uy;uz'; febio_spec.Output.logfile.node_data{1}.ATTR.delim=','; febio_spec.Output.logfile.element_data{1}.ATTR.file=febioLogFileName_strainEnergy; febio_spec.Output.logfile.element_data{1}.ATTR.data='sed'; febio_spec.Output.logfile.element_data{1}.ATTR.delim=',';
Quick viewing of the FEBio input file structure
The febView function can be used to view the xml structure in a MATLAB figure window.
febView(febio_spec); %Viewing the febio file
Exporting the FEBio input file
Exporting the febio_spec structure to an FEBio input file is done using the febioStruct2xml function.
febioStruct2xml(febio_spec,febioFebFileName); %Exporting to file and domNode
Running the FEBio analysis
To run the analysis defined by the created FEBio input file the runMonitorFEBio function is used. The input for this function is a structure defining job settings e.g. the FEBio input file name. The optional output runFlag informs the user if the analysis was run succesfully.
febioAnalysis.run_filename=febioFebFileName; %The input file name febioAnalysis.run_logname=febioLogFileName; %The name for the log file febioAnalysis.disp_on=1; %Display information on the command window febioAnalysis.runMode='external';%'internal'; [runFlag]=runMonitorFEBio(febioAnalysis);%START FEBio NOW!!!!!!!!
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
--------> RUNNING/MONITORING FEBIO JOB <-------- 16-Dec-2020 11:31:25
FEBio path: /home/kevin/FEBioStudio/bin/febio3
# Attempt removal of existing log files 16-Dec-2020 11:31:25
* Removal succesful 16-Dec-2020 11:31:25
# Attempt removal of existing .xplt files 16-Dec-2020 11:31:25
* Removal succesful 16-Dec-2020 11:31:25
# Starting FEBio... 16-Dec-2020 11:31:25
Max. total analysis time is: Inf s
* Waiting for log file creation 16-Dec-2020 11:31:25
Max. wait time: 30 s
* Log file found. 16-Dec-2020 11:31:25
# Parsing log file... 16-Dec-2020 11:31:25
number of iterations : 1 16-Dec-2020 11:31:26
number of reformations : 1 16-Dec-2020 11:31:26
------- converged at time : 0.0166667 16-Dec-2020 11:31:26
number of iterations : 6 16-Dec-2020 11:31:27
number of reformations : 6 16-Dec-2020 11:31:27
------- converged at time : 0.04 16-Dec-2020 11:31:27
number of iterations : 6 16-Dec-2020 11:31:30
number of reformations : 6 16-Dec-2020 11:31:30
------- converged at time : 0.0686667 16-Dec-2020 11:31:30
number of iterations : 6 16-Dec-2020 11:31:31
number of reformations : 6 16-Dec-2020 11:31:31
------- converged at time : 0.1016 16-Dec-2020 11:31:31
number of iterations : 5 16-Dec-2020 11:31:33
number of reformations : 5 16-Dec-2020 11:31:33
------- converged at time : 0.137947 16-Dec-2020 11:31:33
number of iterations : 13 16-Dec-2020 11:31:37
number of reformations : 13 16-Dec-2020 11:31:37
------- converged at time : 0.177024 16-Dec-2020 11:31:37
number of iterations : 8 16-Dec-2020 11:31:39
number of reformations : 8 16-Dec-2020 11:31:39
------- converged at time : 0.216911 16-Dec-2020 11:31:39
number of iterations : 10 16-Dec-2020 11:31:42
number of reformations : 10 16-Dec-2020 11:31:42
------- converged at time : 0.258821 16-Dec-2020 11:31:42
number of iterations : 11 16-Dec-2020 11:31:46
number of reformations : 11 16-Dec-2020 11:31:46
------- converged at time : 0.302349 16-Dec-2020 11:31:46
number of iterations : 11 16-Dec-2020 11:31:49
number of reformations : 11 16-Dec-2020 11:31:49
------- converged at time : 0.346963 16-Dec-2020 11:31:49
number of iterations : 6 16-Dec-2020 11:31:51
number of reformations : 6 16-Dec-2020 11:31:51
------- converged at time : 0.39248 16-Dec-2020 11:31:51
number of iterations : 13 16-Dec-2020 11:31:55
number of reformations : 13 16-Dec-2020 11:31:55
------- converged at time : 0.438894 16-Dec-2020 11:31:55
number of iterations : 10 16-Dec-2020 11:31:58
number of reformations : 10 16-Dec-2020 11:31:58
------- converged at time : 0.485574 16-Dec-2020 11:31:58
number of iterations : 8 16-Dec-2020 11:32:01
number of reformations : 8 16-Dec-2020 11:32:01
------- converged at time : 0.532918 16-Dec-2020 11:32:01
number of iterations : 12 16-Dec-2020 11:32:07
number of reformations : 12 16-Dec-2020 11:32:07
------- converged at time : 0.578951 16-Dec-2020 11:32:07
number of iterations : 9 16-Dec-2020 11:32:10
number of reformations : 9 16-Dec-2020 11:32:10
------- converged at time : 0.625453 16-Dec-2020 11:32:10
number of iterations : 11 16-Dec-2020 11:32:13
number of reformations : 11 16-Dec-2020 11:32:13
------- converged at time : 0.672655 16-Dec-2020 11:32:13
number of iterations : 12 16-Dec-2020 11:32:17
number of reformations : 12 16-Dec-2020 11:32:17
------- converged at time : 0.720326 16-Dec-2020 11:32:17
number of iterations : 13 16-Dec-2020 11:32:21
number of reformations : 13 16-Dec-2020 11:32:21
------- converged at time : 0.768272 16-Dec-2020 11:32:21
number of iterations : 12 16-Dec-2020 11:32:24
number of reformations : 12 16-Dec-2020 11:32:24
------- converged at time : 0.81637 16-Dec-2020 11:32:24
number of iterations : 13 16-Dec-2020 11:32:28
number of reformations : 13 16-Dec-2020 11:32:28
------- converged at time : 0.864692 16-Dec-2020 11:32:28
number of iterations : 9 16-Dec-2020 11:32:31
number of reformations : 9 16-Dec-2020 11:32:31
------- converged at time : 0.91314 16-Dec-2020 11:32:31
number of iterations : 13 16-Dec-2020 11:32:35
number of reformations : 13 16-Dec-2020 11:32:35
------- converged at time : 0.961897 16-Dec-2020 11:32:35
number of iterations : 10 16-Dec-2020 11:32:38
number of reformations : 10 16-Dec-2020 11:32:38
------- converged at time : 1 16-Dec-2020 11:32:38
Elapsed time : 0:01:13 16-Dec-2020 11:32:38
N O R M A L T E R M I N A T I O N
# Done 16-Dec-2020 11:32:38
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
Import FEBio results
if 1%runFlag==1 %i.e. a succesful run
Importing nodal displacements from a log file
dataStruct=importFEBio_logfile(fullfile(savePath,febioLogFileName_disp),1,1);
%Access data
N_disp_mat=dataStruct.data; %Displacement
timeVec=dataStruct.time; %Time
%Create deformed coordinate set
V_DEF=N_disp_mat+repmat(V,[1 1 size(N_disp_mat,3)]);
Importing element stress from a log file
dataStruct=importFEBio_logfile(fullfile(savePath,febioLogFileName_strainEnergy),1,1);
%Access data
E_energy=dataStruct.data;
indBlob=unique(Fb_blob(:));
t=linspace(0,2*pi,250)';
V_def_blob=V(indBlob,:)+N_disp_mat(indBlob,:,end);
[~,indMin]=min(V_def_blob(:,1));
[~,indMax]=max(V_def_blob(:,1));
xEnd=V_def_blob(indMin,1);
xStart=V_def_blob(indMax,1);
rEnd=sphereRadius+(xEnd.*((sphereRadius-tubeRadius(2))/tubeLength));
rStart=sphereRadius+(xStart.*((sphereRadius-tubeRadius(2))/tubeLength));
xMid=mean([xStart xEnd]);%sum([rStart rEnd].*[xStart xEnd])./sum([rStart rEnd]);
rMid=sphereRadius+(xMid.*((sphereRadius-tubeRadius(2))/tubeLength));
V_plot_xEnd=[xEnd*ones(size(t)) rEnd*cos(t) rEnd*sin(t)];
V_plot_xMid=[xMid*ones(size(t)) rMid*cos(t) rMid*sin(t)];
V_plot_xStart=[xStart*ones(size(t)) rStart*cos(t) rStart*sin(t)];
Plotting the simulated results using anim8 to visualize and animate deformations
DN_magnitude=sqrt(sum(N_disp_mat(:,:,end).^2,2)); %Current displacement magnitude % Create basic view and store graphics handle to initiate animation hf=cFigure; hold on; ht=gtitle(['Radial stretch: ',num2str(rMid/sphereRadius)]); hp1=gpatch(Fb_blob,V_DEF(:,:,end),DN_magnitude,'none',1); %Add graphics object to animate hp2=plotV(V_plot_xEnd ,'r-','LineWidth',3); hp3=plotV(V_plot_xMid ,'r-','LineWidth',3); hp4=plotV(V_plot_xStart,'r-','LineWidth',3); gpatch(F_tube,V_DEF(:,:,end),'kw','none',0.25); %Add graphics object to animate axisGeom(gca,fontSize); colormap(cMap); colorbar; caxis([0 max(DN_magnitude(:))]); caxis manual; axis(axisLim(V_DEF)); %Set axis limits statically camlight headlight; lighting gouraud; view(0,0); % view(-30,30); zoom(1.5); axis off; drawnow; LMid=1; % Set up animation features animStruct.Time=timeVec; %The time vector for qt=1:1:size(N_disp_mat,3) %Loop over time increments DN=N_disp_mat(:,:,qt); %Current displacement DN_magnitude=sqrt(sum(DN.^2,2)); V_def=V_DEF(:,:,qt); %Current nodal coordinates V_def_blob=V_def(indBlob,:); [~,indMin]=min(V_def_blob(:,1)); [~,indMax]=max(V_def_blob(:,1)); xEnd=V_def_blob(indMin,1); xStart=V_def_blob(indMax,1); rEnd=sphereRadius+(xEnd.*((sphereRadius-tubeRadius(2))/tubeLength)); rStart=sphereRadius+(xStart.*((sphereRadius-tubeRadius(2))/tubeLength)); xMid=mean([xStart xEnd]);%sum([rStart rEnd].*[xStart xEnd])./sum([rStart rEnd]); rMid=sphereRadius+(xMid.*((sphereRadius-tubeRadius(2))/tubeLength)); LMid=min(LMid,rMid/sphereRadius); V_plot_xEnd=[xEnd*ones(size(t)) rEnd*cos(t) rEnd*sin(t)]; V_plot_xMid=[xMid*ones(size(t)) rMid*cos(t) rMid*sin(t)]; V_plot_xStart=[xStart*ones(size(t)) rStart*cos(t) rStart*sin(t)]; %Set entries in animation structure animStruct.Handles{qt}=[hp1 hp1 hp2 hp2 hp2 hp3 hp3 hp3 hp4 hp4 hp4 ht]; %Handles of objects to animate animStruct.Props{qt}={'Vertices','CData','XData','YData','ZData','XData','YData','ZData','XData','YData','ZData','String'}; %Properties of objects to animate animStruct.Set{qt}={V_def,DN_magnitude,... V_plot_xEnd(:,1),V_plot_xEnd(:,2),V_plot_xEnd(:,3),... V_plot_xMid(:,1),V_plot_xMid(:,2),V_plot_xMid(:,3),... V_plot_xStart(:,1),V_plot_xStart(:,2),V_plot_xStart(:,3),... ['Radial stretch: ',num2str(rMid/sphereRadius)]}; %Property values for to set in order to animate end anim8(hf,animStruct); %Initiate animation feature drawnow;
end
GIBBON www.gibboncode.org
Kevin Mattheus Moerman, [email protected]
GIBBON footer text
License: https://github.com/gibbonCode/GIBBON/blob/master/LICENSE
GIBBON: The Geometry and Image-based Bioengineering add-On. A toolbox for image segmentation, image-based modeling, meshing, and finite element analysis.
Copyright (C) 2006-2020 Kevin Mattheus Moerman
This program is free software: you can redistribute it and/or modify it under the terms of the GNU General Public License as published by the Free Software Foundation, either version 3 of the License, or (at your option) any later version.
This program is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for more details.
You should have received a copy of the GNU General Public License along with this program. If not, see http://www.gnu.org/licenses/.