If the New simulation button is pressed whilst another simulation is already running, the geometry will be cleared but the simulation continues to run. Afte r the lastmost iteration is completed the windows updates with the result anyway and if an attempt is made to run the simulation again the following error occurs:
Exception in thread "AWT-EventQueue-0" java.lang.ArrayIndexOutOfBoundsException
    at java.lang.System.arraycopy(Native Method)
    at javax.swing.text.CompositeView.replace(CompositeView.java:204)
    at javax.swing.text.BoxView.replace(BoxView.java:181)
    at javax.swing.text.View.updateChildren(View.java:1116)
    at javax.swing.text.View.insertUpdate(View.java:700)
    at javax.swing.plaf.basic.BasicTextUI$RootView.insertUpdate(BasicTextUI.java:1602)
    at javax.swing.plaf.basic.BasicTextUI$UpdateHandler.insertUpdate(BasicTextUI.java:1861)
    at javax.swing.text.AbstractDocument.fireInsertUpdate(AbstractDocument.java:202)
    at javax.swing.text.AbstractDocument.handleInsertString(AbstractDocument.java:749)
    at javax.swing.text.AbstractDocument.insertString(AbstractDocument.java:708)
    at rootgui.view.DisplayViewFrame.printlnStd(DisplayViewFrame.java:1052)
    at rootgui.view.DisplayViewFrame$1.actionPerformed(DisplayViewFrame.java:262)
    at javax.swing.AbstractButton.fireActionPerformed(AbstractButton.java:2018)
    at javax.swing.AbstractButton$Handler.actionPerformed(AbstractButton.java:2341)
    at javax.swing.DefaultButtonModel.fireActionPerformed(DefaultButtonModel.java:402)
    at javax.swing.DefaultButtonModel.setPressed(DefaultButtonModel.java:259)
    at javax.swing.plaf.basic.BasicButtonListener.mouseReleased(BasicButtonListener.java:252)
    at java.awt.AWTEventMulticaster.mouseReleased(AWTEventMulticaster.java:289)
    at java.awt.Component.processMouseEvent(Component.java:6505)
    at javax.swing.JComponent.processMouseEvent(JComponent.java:3321)
    at java.awt.Component.processEvent(Component.java:6270)
    at java.awt.Container.processEvent(Container.java:2229)
    at java.awt.Component.dispatchEventImpl(Component.java:4861)
    at java.awt.Container.dispatchEventImpl(Container.java:2287)
    at java.awt.Component.dispatchEvent(Component.java:4687)
    at java.awt.LightweightDispatcher.retargetMouseEvent(Container.java:4832)
    at java.awt.LightweightDispatcher.processMouseEvent(Container.java:4492)
    at java.awt.LightweightDispatcher.dispatchEvent(Container.java:4422)
    at java.awt.Container.dispatchEventImpl(Container.java:2273)
    at java.awt.Window.dispatchEventImpl(Window.java:2719)
    at java.awt.Component.dispatchEvent(Component.java:4687)
    at java.awt.EventQueue.dispatchEventImpl(EventQueue.java:713)
    at java.awt.EventQueue.access$000(EventQueue.java:104)
    at java.awt.EventQueue$3.run(EventQueue.java:672)
    at java.awt.EventQueue$3.run(EventQueue.java:670)
    at java.security.AccessController.doPrivileged(Native Method)
    at java.security.ProtectionDomain$1.doIntersectionPrivilege(ProtectionDomain.java:76)
    at java.security.ProtectionDomain$1.doIntersectionPrivilege(ProtectionDomain.java:87)
    at java.awt.EventQueue$4.run(EventQueue.java:686)
    at java.awt.EventQueue$4.run(EventQueue.java:684)
    at java.security.AccessController.doPrivileged(Native Method)
    at java.security.ProtectionDomain$1.doIntersectionPrivilege(ProtectionDomain.java:76)
    at java.awt.EventQueue.dispatchEvent(EventQueue.java:683)
    at java.awt.EventDispatchThread.pumpOneEventForFilters(EventDispatchThread.java:244)
    at java.awt.EventDispatchThread.pumpEventsForFilter(EventDispatchThread.java:163)
    at java.awt.EventDispatchThread.pumpEventsForHierarchy(EventDispatchThread.java:151)
    at java.awt.EventDispatchThread.pumpEvents(EventDispatchThread.java:147)
    at java.awt.EventDispatchThread.pumpEvents(EventDispatchThread.java:139)
    at java.awt.EventDispatchThread.run(EventDispatchThread.java:97)