Dear Steven and Meep users,
The geometry for my case is a tapered cone (axis (1 0 0)). It is easy to
see from the PNG file whether or not the geometry resulting from (set!
symmetries (list (make ... is symmetric or not.
I have found that the geometry resulting from
(make mirror-sym (direction Y )) is symmetric, also
(make rotate2-sym (direction X )) gives symmetric geometry but,
(make rotate4-sym (direction X )) displays only half the cone.
The fields must be considered. When I run with default phase the Ez
field appears to be correct for mirror-sym, but it is not correct with
rotate2-sym . This is expected as the default phase is +1. When I set
the phase switch (phase -1) or even (phase 1) Guile throws an error,
ERROR: Wrong type (expecting exact integer): #f
With the rotate4-sym setting it is impossible to tell whether or not the
fields are symmetric from only half the geometry.
You may note that the one case that works is mirror-sym with the
direction Y, when the Geometric axis of symmetry is X.
If anyone wants to play with symmetry, feel free to use my SCHEME test
file, attached.
(reset-meep)
(define-param c 299792458.) ; Speed of light
(define-param meple 1.0e-2) ; Characteristic length 0.15943 .024
; Signal parameters - SI units
(define-param freq 1880.4e+6) ; Frequency (1880.4MHz claimed)
(define-param waveling (/ c freq)) ; Wavelength, ~0.159 m
; ------------------ Set the lattice and coordinate system
(set! geometry-lattice (make lattice (size 20 20 no-size) ))
(set! pml-layers (list (make pml (thickness 1.0))))
(set! resolution 20)
(display "signal parameters")(newline)
; Signal Parameters in Meep units
(define mple_c 1) ; Speed of light = 1 in Meep
(define mple_t (/ meple c)) ; Time
(define-param mple_f (* freq mple_t)) ; Source Frequency
(define-param mple_f (/ meple waveling)) ; Source Frequency
(newline)
(print " frequency = ") (display freq) (newline)
(print " mple_f = ") (display mple_f) (newline)
(print " mple_t = ") (display mple_t) (newline)
(print " meple = ") (display meple) (newline)
(display "set geometry") (newline)
(set! geometry (list ; Start of Geometry
; A tapered tin can.
(make cone (center 0 0 0) (radius 5)
(radius2 2) (height 8.5) (material metal) (axis 1 0 0) )
(make cone (center 0 0 0) (radius 4.97)
(radius2 1.97) (height 8.497) (material air) (axis 1 0 0) )
))
(display "set source" ) (newline)
(set! sources (list (make source ; ******Continuous source*******
(src (make continuous-src (frequency mple_f) (end-time 200)))
(component Ez) (center 0 0 )
)))
(display "set symmetries") (newline)
(set! symmetries (list ; ******** Symmetry **********
; *
(make rotate4-sym (direction X )) ; (phase -1) ;defaults to +1 *
; ERROR: Wrong type (expecting exact integer): #f
; *
)) ; *****************
(display "Continuous 1, RUNing Continuous source") (newline)
(run-until 10 ; ******* RUN Continuous source ****
(at-beginning output-epsilon)
(at-end output-efield-z))
(newline) (display "DONE") (newline)(newline)
(quit)
; h5topng ./sym-eps-000000.00.h5
; h5topng -S1 -Zc dkbluered -a yarg -A ./sym-eps-000000.00.h5 ./sym-ez-000010.00.h5
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