# Example 8 -- Plot T=T(x,rho) section of eubex data

`Initialize Parameters'
{
    \FILE_DATA = "example8a.dat" # T vs rho
    \FILE_LOCN = "example8b.dat" # section distances
    set missing value -99.0
    #
    # Following values from ~/eubex/processing/to_rho_bins/do_rho_inter
    \RHO_MIN = "28.1"
    \RHO_MAX = "27.5"
    \RHO_INC = "-0.002"
    \NY = "301"
    \xmin = "350"
    \xmax = "0"
    \xinc = "-100"
    \ymin = "28.1"
    \ymax = "27.8"
    \yinc = "-0.1"
    \zmin = "0"
    \zmax = "2.5"
}
`Initialize Axes'
/*
Set up axes
*/
{
    set x name "km"
    set x size 10
    set x axis \xmin \xmax \xinc
    set y name "$\sigma_T$"
    set y size 5
    set y axis name horizontal
    set y axis \ymin \ymax \yinc
    set y format "%.1f"
}
`Initialize Files'
{
    query \data "Data file?   " ("\FILE_DATA")
    query \locn "Station locn?" ("\FILE_LOCN")
}
`Read Data'
{
    # Read x-locations
    system awk '{print $2}' < \locn > TMP
    system wc TMP | awk '{print $1}' > NUM
    open NUM
    read .gridx_number.
    close
    system rm NUM 
    open TMP
    read grid x .gridx_number.
    close
    system rm TMP
    # Create y-locations
    set y grid \RHO_MIN \RHO_MAX \RHO_INC
    #
    # Read data
    open \data
    read grid data \NY .gridx_number.
    close
}
`Plot Contours'
{
    set graylevel .contour_graylevel.
    set clip on
    set line width 0.5
    draw contour -3 3 0.25 unlabelled
    #
    # wide line at 0 degrees
    set line width 2
    draw contour 0 unlabelled
}
`Plot Image And Maybe Contours'
{
    \imagefile = "image"
    set image range \zmin \zmax
    convert grid to image box \xmin  \ymin \xmax \ymax
    query \dohisto "Do histogram scaling? (yes|no)" ("yes")
    \incs = "no"
    if {"\dohisto" == "yes"}
	set image grayscale using histogram
    else
	\zinc = "0.25"
	query \incs "In linear scaling, band at an increment of \zinc?" ("yes")
	if {"\incs" == "yes"}
	    set image grayscale black \zmin white \zmax increment \zinc
	else
	    set image grayscale black \zmin white \zmax
	end if
    end if
    write image rasterfile to \imagefile
    show "wrote image rasterfile `\imagefile '"
    draw image
    draw image palette
    query \do_contours "Do contours as well (yes|no)" ("yes")
    if {"\do_contours" == "yes"}
	Plot Contours
    end if
    draw title "Example 8 -- \data black=\zmin white=\zmax"
    if {"\dohisto" == "yes"}
	draw title "Histogram enhanced grayscales"
    else
	if {"\incs" == "yes"}
	    draw title "Grayscale banded at intervals of \zinc"
	end if
    end if
}
Initialize Parameters
Initialize Axes
Initialize Files
Read Data
query \doimage "Draw image (yes|no)" ("no")
if {"\doimage" == "yes"}
    .contour_graylevel. = 1	# white contours 
    Plot Image And Maybe Contours
else
    .contour_graylevel. = 0	# black contours 
    Plot Contours
    draw title "Example 8"
end if

