epsilon.png image is skewed

Dear mpb users,
I am trying to get band gap with supercell.
my supercell epsilon image is not circular(attached link first image )
I read the explanation in mpb wiki page.
(http://ab-initio.mit.edu/wiki/index.php/MPB_Data_Analysis_Tutorial)

I applied to following command in order to get correct image.

unix% mpb-data -r -m 3 -n 32 epsilon.h5

unix% h5topng epsilon.h5:data-new

But I have not obtained correct image yet(attached link second image).
Could you check my ctl file.
best regards...
Onder

first image:
http://okarakilinc.pau.edu.tr/files/epsilon_first.png

second image:
http://okarakilinc.pau.edu.tr/files/epsilon_second.png



-------------------------------------------------------------------
(define-param epssub 13)       ; dielectric substrate
(define-param epsair 1)
(define-param r 0.2)         ; the radius of the holes
(define-param supercell-y 31) ; the (odd) number of lateral supercell periods

(set! default-material (make dielectric (epsilon epssub)))

; triangular lattice with vertical supercell:
(set! geometry-lattice (make lattice (size 1  supercell-y no-size)
                         (basis1 (/ (sqrt 3) 2) 0.5)
                         (basis2 (/ (sqrt 3) 2) -0.5)))

;;;;;;;;;;;;;;;;;;;;;;;; Geometry

(define-param a 1)
(define-param d (* (/ (sqrt 3) 2) a))

(set! geometry
 (append
    (geometric-objects-lattice-duplicates
  (list
            (make cylinder (center 0 0) (radius r) (height infinity)
(material (make dielectric (epsilon epsair)))
                        )
                        (make cylinder (center (* .5 a) (* -1 d)) (radius
r) (height infinity)
(material (make dielectric (epsilon epsair)))
                 )
   )
     1 (* a (sqrt 3) a))

  ))


; 1st Brillouin zone of a triangular lattice:
(define Gamma (vector3 0 0 0))
(define K' (lattice->reciprocal (vector3 0.5 0 0))) ; edge of Brillouin zone.

(define-param only-K false) ; run with only-K=true to only do this k-point
(define-param k-interp 9)   ; the number of k points to interpolate
(if only-K
    (set! k-points (list K))
    (set! k-points (interpolate k-interp (list Gamma K'))))


(define-param res 32)
(set! grid-size (vector3 res (* res supercell-y) 1))

(define-param extra-bands 21)

(set! num-bands (+ supercell-y extra-bands))

(set-param! mesh-size 7)

(run-tm)