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; Code to output the data needed for a wavevector diagram at a grid of
; k points, suitable for plotting with a contour-plot program.
(define (kgrid kx-min kx-max ky-min ky-max nkx nky)
(map (lambda (kx)
(interpolate nky (list (vector3 kx ky-min) (vector3 kx ky-max))))
(interpolate nkx (list kx-min kx-max))))
; output a bunch of lines of the form:
; kgrid:, band#, kx, frequencies at kys...
; Frequencies above the light cone omega > c |k| / n-lightcone are
; excluded (multiplied by -1); set n-lightcone = 0 to disable this.
(define (wavevector-diagram kgrid parity n-lightcone)
(map (lambda (kylist)
(set! k-points kylist)
(run-parity parity true)
(map
(lambda (band)
(print "kgrid:, " band ", " (vector3-x (car kylist)))
(map (lambda (freqs k)
(print ", "
(* (if (and (positive? n-lightcone)
(> (list-ref freqs (- band 1))
(* n-lightcone
(vector3-norm
(reciprocal->cartesian k)))))
-1
1)
(list-ref freqs (- band 1)))))
all-freqs k-points)
(print "\n"))
(arith-sequence 1 1 num-bands)))
kgrid))
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