; This batch file creates a bar chart used as an example in
; Chapter 10, "Plotting", of _Using IDL_.

; Compile the file plot05.pro, which contains two IDL procedures
; named "BOX" and "BARGRAPH". 

.r plot05.pro

; Run a batch file to define the variables used in this plot.

@plot01

; Define tick x values: 0.2, 0.4, 0.6, 0.8.

XVAL = FINDGEN(4)/5. + .2	

; Make a vector of scores from first year, corresponding to the name 
; vector from above.

YVAL = [COHO(0), SOCKEYE(0), HUMPBACK(0), CHINOOK(0)]

; Make the axes with no data. Force x range to [0, 1], centering xval, 
; which also contains the tick values. Force three tick intervals making 
; four tick marks. Specify the tick names from the names vector.

PLOT, XVAL, YVAL, /YNOZERO, XRANGE = [0,1], XTICKV = XVAL, $
    XTICKS = 3, XTICKNAME = NAMES, /NODATA, TITLE = 'Salmon Populations, 1967'	

; Draw the boxes, centered over the tick marks. !Y.CRANGE(0) is the 
; y value of the bottom x-axis.

FOR I = 0, 3 DO BOX, XVAL(I) - .08, !Y.CRANGE(0), $
    XVAL(I) + 0.08, YVAL(I), 128