; This batch file creates a contour plot that is sized to match
; the image data. This example is from Chapter 11, "Plotting
; Multi-dimensional Arrays", of _Using IDL_.

; Restore variables elev, X, and Y.

@cntour01

; Set missing data points to a large value.

elev(WHERE(elev EQ 0)) = 1E6	

; REBIN down to a 72 x 92 matrix.

new = REBIN(elev, 360/5, 460/5)	

; Scale image intensities.

image = BYTSCL(elev, MIN=2658, MAX=4241)	

;Get size of plot window in device pixels.

PX = !X.WINDOW * !D.X_VSIZE	
PY = !Y.WINDOW * !D.Y_VSIZE

; Get the size of the image.

SZ = SIZE(image)

; Display the image with its lower-left corner at the origin of the plot 
; window.

TVSCL, image, PX(0), PY(0)

; Write the contours over the image, being sure to use the exact axis 
; styles so that the contours fill the plot window. Inhibit erasing.

CONTOUR, new, X, Y, XSTYLE = 1, YSTYLE = 1, $
    POSITION = [PX(0), PY(0), PX(0) + SZ(1) - 1, PY(0) + SZ(2) - 1], $
    LEVELS = 2750 + FINDGEN(6) * 250., $ MAX_VALUE = 5000, $
    TITLE='Maroon Bells Region', SUBTITLE = '250 meter contours', $
    XTITLE = 'UTM Coordinates (KM)', /NOERASE, /DEVICE