Color patterns on maps

    Glat = gmt("grdmath -Rd -I1 -r Y COSD 2 POW =")
    Glon = gmt("grdmath -Rd -I1 -r X =")
    lat_cpt = makecpt(color="white,blue", range=(0,1), continuous=true, no_bg=true)
    lon_cpt = makecpt(cmap=:rainbow, range=(-180,180))
    grdimage(Glat, cmap=lat_cpt, frame=:none, interp=:l, proj=:sinu,
             figsize=16, y_off=18)
    coast!(area=5000, clip=:land)
    grdimage!(Glon, cmap=lon_cpt, interp=:l)
    coast!(clip=:end)
    coast!(area=5000, shore=:thinnest)
    text!(text_record([0 20], "16TH INTERNATIONAL"),
          font=(32,"Helvetica-Bold","red=thinner"))
    text!(text_record([0 -10], "GMT CONFERENCE"),
          font=(32,"Helvetica-Bold","red=thinner"))
    text!(text_record([0 -30], "Honolulu, Hawaii, April 1, 2019"),
          font=(18,"Helvetica-Bold","green=thinner"))

    # Then show example of color patterns and placing a PostScript image
    coast!(area=5000, land=(pattern=86, bg=:yellow, fg=:red, dpi=100),
           water=(pattern="@circuit.png", dpi=100), frame=:none, y_off=-8)
    text!(text_record([0 30], "SILLY USES OF"),
          font=(32,"Helvetica-Bold","lightgreen=thinner"))
    text!(text_record([0 -30], "COLOR PATTERNS"),
          font=(32,"Helvetica-Bold","magenta=thinner"))
    psimage!("@GMT_covertext.eps", D="jCM+w3i")

    # Finally repeat 1st plot but exchange the patterns
    grdimage!(Glon, cmap=lon_cpt, frame=:none, interp=:l, y_off=-8)
    coast!(area=5000, clip=:land)
    grdimage!(Glat, cmap=lat_cpt, interp=:l)
    coast!(clip=:end)
    coast!(area=5000, shore=:thinnest)
    text!(text_record([0  20], "15TH INTERNATIONAL"),
          font=(32,"Helvetica-Bold","red=thinner"))
    text!(text_record([0 -10], "GMT CONFERENCE"),
          font=(32,"Helvetica-Bold","red=thinner"))
    text!(text_record([0 -30], "Honolulu, Hawaii, April 1, 2018"),
          font=(18,"Helvetica-Bold","green=thinner"), show=true)