IBM Release 1.93 manual

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crosses the centre line of a cell, causing a discontinuous change in the actual object size, and hence in the simulation results. On small scales, therefore, the partial derivatives of any penalty function will be zero in most places, with delta-functions sprinkled round, and the penalty function surfaces exhibit multidimensional cliffs and canyons. This is why we’re not using one of those fancy variable metric optimizers. POEMS has no way of exploring the bottom of a canyon it never encounters, so for simulations with significant economic importance, it’s worth restarting the simulator a few times using the RESTARTS parameter of the COMPUTE statement. (For more discussion, see e.g. W. H. Press et al, Numerical Recipes in C, 2nd Ed., Cambridge (UK), Cambridge University Press, 1991.

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Contents IBM T. J. Watson Research Center Yorktown Heights, NY Page IBM T. J. Watson Research Center Yorktown Heights, NY Using Poems HOW Poems WorksChapter Introduction MotivationPhilosophy Structure OptimizationPage Poems system organization Script Operation Program OrganizationFront-End Script poems.cmd Fdtd Engine FIDO/TEMPEST Postprocessor EmpostVisualization System VIS5D Cluster ControlParallel Processing Global Group Command ReferencePoems Command-Line Options Freq LambdaFunction HostsWhich means that the host’s predefined hostname is not used MacdefMacro PrintSimulator RandomseedSET World Group TitleVerbose BoundaryMaterial Group BasicstepXrange Yrange DefineParameters epsReal epsImag muReal muImag FAN Object GroupBlock Tiledplane GratingHollowbox Cylinder Curve3DCURVE Source Group Command Group Output GroupPostprocess Group FieldCAD WebpageIntegral FarfieldFlux List ModematchMovie MOVIE3DDissipation SliceGuess Optimize GroupVariables Penalty Merit LimitStore Range Schedule GroupParameters Computational Domain SymmetryObjects Perfectly-Matched Layers MaterialsPlane Waves Page Beam Sources Optimization Merit FunctionsPhase uniformity across a plane Worked Example Optimizing a V Antenna 10 Optimized V antenna refractivePage Predefined Constants Worked Example Doped Silica Waveguide ModeWorked Example Glass Ridge Waveguide to Free Space Coupler Reserved Names ConfinePredefined Mathematical Functions Arithmetic OperatorsLogical Operators ABSAcos AcoshATAN2 CeilCOS ElintkIntegral 20. LNMAX MINRandom ROOT1DRound SignFlattop Analytical Pupil FunctionsMaterial Parameter Functions Time step Tempest and General Fdtd InformationStartup and Steady State Page Appendix A. V-Antenna Optimization Run Poems Input DIPOLE2I.PAR END Material END World Subdomain ALL END ObjectEND Output END CommandEND Source END Optimize Phaseex END Postprocess AmplexPage Page Page END Tempest Input File DIPOLE2I.PAR.IN Written by Phil Hobbs Pages of pointsource statements omitted Postprocessor orders DIPOLE2I.ORDERS ALLDIPOLE2IEXI DIPOLE2IEXQDIPOLE2IEYI DIPOLE2IEYQDIPOLE2IEZI DIPOLE2IEZQMiddleflux POSTPROC.1.NAMEArray Amplex POSTPROC.1.PARMSTRINGDIPOLE2IPHASEEX ArrayPOSTPROC.2.PARMSTRING FF2DIPOLE2IPX POSTPROC.6.NAMEArray Poyntingz DIPOLE2IPZPOSTPROC.9.PARMSTRING POSTPROC.10.PARMSTRINGPOSTPROC.11.NAME Slice IndexnSlice Poyntingz POSTPROC.13.COMPARISONDOMAINDIPOLE2IPZXY0.BMP POSTPROC.14.NAMEPOSTPROC.16.COMPARISONDOMAIN DIPOLE2IPXZX0.BMPPOSTPROC.17.NAME Slice AmplexDIPOLE2IPHASEEXXY0.BMP DIPOLE2IPHASEEXZX0.BMPPOSTPROC.20.COMPARISONDOMAIN DIPOLE2IDISSZX0.BMPPOSTPROC.24.COMPARISONDOMAIN DIPOLE2IEXQZX0.BMPRun Results DIPOLE2I.SIMPLEX Page Page Page Page Page Fdtd and Tempest Tempest patchesAdvice common to all or most Fdtd programs Tempest limitationsWindow System Configuration Sample X11 ConfigurationWish list Running Vis5DRelease Notes Beta Release Limitations Page Page Matlab IndexEmdenormal Emunderflow Maxordersources 81 Maxpointsources