Meep release notes
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Here, we describe what has changed between releases of the [[Meep]] package. You can also refer to the <code>NEWS</code> file in the Meep package (or the <code>ChangeLog</code> file for a more detailed listing). | Here, we describe what has changed between releases of the [[Meep]] package. You can also refer to the <code>NEWS</code> file in the Meep package (or the <code>ChangeLog</code> file for a more detailed listing). | ||
{{TOCright}} | {{TOCright}} | ||
+ | |||
+ | ==Meep 1.0== | ||
+ | <small>28 March 2009</small> | ||
+ | |||
+ | * New timestepping scheme for off-diagonal anisotropic epsilon and mu, based on technique by Werner and Cary <nowiki>[</nowiki> ''J. Comp. Phys.'' 226, 1085 (2007) <nowiki>]</nowiki>, that improves FDTD stability when anisotropy is present (such as when subpixel averaging is used on isotropic media). | ||
+ | * Scheme user interface now supports user-specified anisotropic (real-symmetric) epsilon and mu (via <code>epsilon-diag</code>, <code>epsilon-offdiag</code>, <code>mu-diag</code>, and <code>mu-offdiag</code> parameters, similar to MPB). Accurate subpixel averaging of anisotropic media based on the method by Kottke, Farjadpour, & Johnson [ ''Phys. Rev. E.'' 77, 036611 (2008) <nowiki>]</nowiki>. | ||
+ | * Anisotropic dispersive materials are now supported, although currently the dispersive part of the epsilon/mu tensor must be diagonal, via the new <code>sigma-diag</code> parameter of polarizability. (The corresponding C++ interface has also removed <code>delta_epsilon</code>.) | ||
+ | * The <code>delta-epsilon</code> parameter of polarizability has been removed; you should use <code>sigma</code> instead. | ||
+ | * New <code>fields::integrate2</code> function (and corresponding Scheme function <code>integrate2-field-function</code>) to perform integrations involving two simulations with the same computational cell (e.g. field-overlap calculations for coupled-mode theory). | ||
+ | * In the Scheme interface, subpixel averaging is not used for user-specified material-function types; you only get subpixel averaging for the standard shapes (blocks, cylinders, etcetera). | ||
+ | * Haskell code-generation is no longer used, and <code>hsrc</code> directory is removed. Bitrotted and undocumented (hence unused) saturable-absorber feature has been removed, along with <code>energy-saturation</code> parameter of polarizability. | ||
+ | |||
+ | * Some bug-fixes to test programs that made them overly sensitive | ||
+ | to roundoff errors and possibly fail depending on the compiler. | ||
+ | (New fields::round_time and meep-round-time functions to round | ||
+ | times to single-precision, useful for robust time comparisons.) | ||
+ | |||
==Meep 0.20.4== | ==Meep 0.20.4== |
Revision as of 03:44, 29 April 2009
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Here, we describe what has changed between releases of the Meep package. You can also refer to the NEWS
file in the Meep package (or the ChangeLog
file for a more detailed listing).
|
Meep 1.0
28 March 2009
- New timestepping scheme for off-diagonal anisotropic epsilon and mu, based on technique by Werner and Cary [ J. Comp. Phys. 226, 1085 (2007) ], that improves FDTD stability when anisotropy is present (such as when subpixel averaging is used on isotropic media).
- Scheme user interface now supports user-specified anisotropic (real-symmetric) epsilon and mu (via
epsilon-diag
,epsilon-offdiag
,mu-diag
, andmu-offdiag
parameters, similar to MPB). Accurate subpixel averaging of anisotropic media based on the method by Kottke, Farjadpour, & Johnson [ Phys. Rev. E. 77, 036611 (2008) ]. - Anisotropic dispersive materials are now supported, although currently the dispersive part of the epsilon/mu tensor must be diagonal, via the new
sigma-diag
parameter of polarizability. (The corresponding C++ interface has also removeddelta_epsilon
.) - The
delta-epsilon
parameter of polarizability has been removed; you should usesigma
instead. - New
fields::integrate2
function (and corresponding Scheme functionintegrate2-field-function
) to perform integrations involving two simulations with the same computational cell (e.g. field-overlap calculations for coupled-mode theory). - In the Scheme interface, subpixel averaging is not used for user-specified material-function types; you only get subpixel averaging for the standard shapes (blocks, cylinders, etcetera).
- Haskell code-generation is no longer used, and
hsrc
directory is removed. Bitrotted and undocumented (hence unused) saturable-absorber feature has been removed, along withenergy-saturation
parameter of polarizability.
* Some bug-fixes to test programs that made them overly sensitive to roundoff errors and possibly fail depending on the compiler. (New fields::round_time and meep-round-time functions to round times to single-precision, useful for robust time comparisons.)
Meep 0.20.4
17 March 2009
- Bug fix in cylindrical code, which caused it to blow up in some circumstances for nonzero m.
- Bug fix: non-integrated sources with conductivity are now second-order accurate, thanks to Alejandro Rodriguez.
- Bug fix in writing strings with parallel HDF5, thanks to Zheng Li for the bug report.
- Check that PML parameters are sensible (e.g. that total PML thickness is no greater than cell thickness) to avoid common mistakes.
- New
extra-materials
input variable, so that you no longer have to use "dummy objects" to specify the existence of some materials when usingmaterial-function
types.
Meep 0.20.3
24 July 2008
- Fixed circular dependency in
Makefile
, which caused problems with some versions ofmake
; thanks to Kaoru Narita for the bug report.
Meep 0.20.2
21 July 2008
- Fixed incompatibility with Guile 1.6.x or earlier; thanks to the bug report by Andreas Unger.
Meep 0.20.1
20 July 2008
- Improved handling of nested
synchronized-magnetic
calls. - Bug fix: parallel builds (
make -j
) should now work. - Bug fix: pkg-config file was incorrectly installed for MPI version; thanks to Majid Sodagar for the bug report.
Meep 0.20
19 July 2008
- Support for user-specified permeability (mu). Renamed "
dielectric
" to "medium
" in libctl interface, new "mu
" property and newoutput-bfield
andoutput-mu
functions, and new "Permeability
" and "Bx
" etc. field types. - Support for user-specified electric and/or magnetic conductivities. These are especially useful to add a desired dissipation loss (an imaginary part of ε/μ) in a narrow bandwidth, without messing around with Lorentzian dispersive materials.
- Add predefined
perfect-magnetic-conductor
(μ = −∞) material, along withperfect-electric-conductor
(ε = −∞). - Added
synchronized-magnetic
step function to allow step functions to run with the electric and magnetic fields synchronized in time to second-order accuracy. See Synchronizing the magnetic and electric fields. - New PML implementation (UPML instead of split-field), should have lower reflection in many cases.
- User-specified PML profile and asymptotic reflection.
- Internally, all timestepping code is now handwritten (and much shorter) rather than old verbose Haskell-generated code; this should make it easier to add new features.
- Add support for non-integrated current sources, if the
is-integrated?
property of the current is set to false; this is now the default, to make handling of E and H sources more similar and intuitive. - Work with HDF5 1.8 (which previously would not compile unless you manually set a preprocessor flag, due to API changes).
- Check for
ctl.h
in/usr/include/ctl/ctl.h
(default in Fedora), and check for libctl in/usr/share/libctl3
(default in Debian & Ubuntu). - Bug fix: fixed relative phase of E and H sources (which were off from one another by half a timestep); thanks to M. Megens for bug report.
- Bug fix: make sure h5 filenames have unique timestep for cases where Δt is very small or very large.
Meep 0.10.1
13 November 2007
- Bug fix in
flux_in_box
, which accidentally returned the flux multiplied by the number of processors, instead of the flux. - Bug fix in epsilon averaging for structures including metals (ε < 0), fixing an instability.
- Bug fix in
output-png
when running in parallel (removing race condition). - Fixed bug that disabled subpixel averaging for dimensions=1 (thanks to Mischa Megens for the bug report).
- Fixed bug that caused
output-tot-pwr
to stop Meep with an error message; thanks to Vyacheslav Sokolov for the bug report. - Make
at-every
step functions less susceptible to rounding errors; thanks to L. Le Guyader for the bug report. - Fixed bug in dispersive media that wasted memory on parallel machines (the polarization memory was not parallelized); thanks to J. L. Silva for the bug report.
- Bug fix in
output-png+h5
, thanks to a report by Chad Husko. - Fixed several deadlocks that could occur when the parallel Meep is used with a serial HDF5 library (we continue to recommend using the parallel HDF5 library with parallel Meep, however). Thanks in part to Lingling Tang for his bug report.
- For maintainer-mode, improved detection of Haskell package names; thanks to Liang Huo for the bug report.
Meep 0.10
21 August 2006
-
eps-averaging?
is now turned on by default (in libctl interface), using much-improved algorithm by Ardavan Farjadpour. This greatly improves accuracy, and also allows continuous tuning of geometric parameters. (See our upcoming paper in Optics Lett., with a preprint at Citing Meep.) New input variablessubpixel-tol
andsubpixel-maxeval
to control the accuracy of the subpixel averaging. - Support for χ(2) (Pockels) as well as χ(3) (Kerr) nonlinearities.
- Symmetries no longer require the cell size to be an even number of pixels. Previously, Meep exited with an error in this case, whereas now it simply adds an extra pixel to the cell size as needed.
- New
with-prefix
step function to allow you to use a differentfilename-prefix
for selected outputs. - New feature for
output-png
: built-in shell variable$EPS
that refers to the last-output epsilon.h5
file, which you can use to easily add dielectric contours/overlays to the field output image. - Added
output-png+h5
function that outputs both.png
and.h5
files. - New functions
flux-in-box
,electric-energy-in-box
,magnetic-energy-in-box
, andfield-energy-in-box
(convenience wrappers around C++ functions). - Bug fix in Kerr nonlinearity:
chi3
was accidentally scaled by factor. - Bug fix: if you specified three or more symmetries, at most two symmetries were used (ignoring the rest).
- Bug fix in
rotate2
symmetry, which wasn't working correctly. - Bug fix in
add-flux
for multiple flux regions, thanks to K. Choi. - Bug fix in
harminv
where it wouldn't allow you to callharminv
more than once for the same run loop; thanks to Aristos Karalis. - Bug fix in
save-flux
/load-flux
that prevented it from working properly without output directories, thanks to Karl Koch. - Fixed abort that sometimes occurred due to rounding when the source was the same width as the cell (thanks to G. J. Parker).
- Fixed minor build problems on Cygwin, SGI, and other systems, thanks to Christopher Kang, Robyn Landers, Florencio Garcia, and others.
Meep 0.9
1 April 2006
- Initial public release.