Markers in XY plot legend

Hi NCLers,

I need advice on how to add markers to my line legend in an XY plot.
The self-contained script below correctly places markers (crosses and
circles) on the curves in the main graphic, but I cannot figure out
how to make the markers appear in the legend, i.e., in the short lines
in the upper left corner next to the explanatory legend.
I've tried drawing the legend with both gsn_polyline and
gsn_add_polyline, and neither gives me the markers, although both
give the correct line colors and dash styles.

Any help appreciated,
Charlie
************************************************************************
; Usage:
; cd ~/ncl;ncl < tst.ncl

begin

load "$NCARG_ROOT/lib/ncarg/nclscripts/csm/gsn_code.ncl"
load "$NCARG_ROOT/lib/ncarg/nclscripts/csm/gsn_csm.ncl"

; Initialize some fields
mss_val=1.0e36

; Markers: http://www.ncl.ucar.edu/Document/Graphics/Images/markers.gif
idx_mrk_crc=04 ; Circle
idx_mrk_crs=05 ; Cross

ttl_sng="Binary Operation Counts Satellite Dataset"
x_ttl_sng="Dataset Size N/N:B:0:N: (N:B:0:N:=9.3 x 10:S:6:N:)"
y_ttl_sng="Integer Ops. x 10:S:8:N:; Floating Ops. x 10:S:6:N:"

abc=(/1,2,4,6,8/)
abc_nbr=dimsizes(abc)
ord_nbr=4
data=new((/ord_nbr,abc_nbr/),float,mss_val)
ntg_obs=(/1.50, 3.71, 7.35, 10.9, 14.7/)
flp_obs=(/7.47088, 1.87099e+01, 3.74527e+01, 5.61626e+01,
7.48399e+01/)
ntg_mdl=(/1.680, 3.359, 6.718, 10.08, 13.44/)
flp_mdl=(/9.3312, 18.6624, 37.3248, 55.9872, 74.6496/)

idx_flp_obs=0
idx_flp_mdl=1
idx_ntg_obs=2
idx_ntg_mdl=3

data(idx_ntg_obs,:)=ntg_obs
data(idx_flp_obs,:)=flp_obs
data(idx_ntg_mdl,:)=ntg_mdl
data(idx_flp_mdl,:)=flp_mdl

dat_sng=new((/ord_nbr/),string)
dat_sng(idx_ntg_obs)="Int. Obs."
dat_sng(idx_flp_obs)="Float Obs."
dat_sng(idx_ntg_mdl)="Int. Mdl."
dat_sng(idx_flp_mdl)="Float Mdl."

clr_sng=new((/ord_nbr/),string)
clr_sng(idx_ntg_obs)="black"
clr_sng(idx_flp_obs)="black"
clr_sng(idx_ntg_mdl)="green"
clr_sng(idx_flp_mdl)="green"

ln_sty=0*new(ord_nbr,integer)
ln_sty(idx_flp_obs)=0
ln_sty(idx_flp_mdl)=0
ln_sty(idx_ntg_obs)=50
ln_sty(idx_ntg_mdl)=50

ln_thk=new(ord_nbr,integer)
ln_thk(:)=2

; Marker properties
mrk_ln_md=new((/ord_nbr/),string)
mrk_ln_md(:)="MarkLines" ; Line/marker combinations
mrk_clr=clr_sng ; Marker color
mrk_sz=new(ord_nbr,float)
mrk_sz(:)=0.01
mrk_typ=new(ord_nbr,integer)
mrk_typ(idx_ntg_obs)=idx_mrk_crs
mrk_typ(idx_flp_obs)=idx_mrk_crs
mrk_typ(idx_ntg_mdl)=idx_mrk_crc
mrk_typ(idx_flp_mdl)=idx_mrk_crc

rsr=True
rsr_at_gsnDraw=False
rsr_at_gsnFrame=False
rsr_at_gsnStringFont="helvetica"
rsr_at_tiMainFont="helvetica"
rsr_at_tiMainString=ttl_sng
rsr_at_tiXAxisFont="helvetica"
rsr_at_tiXAxisString=x_ttl_sng
rsr_at_tiYAxisFont="helvetica"
rsr_at_tiYAxisFontHeightF=.020
rsr_at_tiYAxisOn=True
rsr_at_tiYAxisString=y_ttl_sng
rsr_at_tmXBLabelFont="helvetica"
rsr_at_tmXTOn=False
rsr_at_tmYLLabelFont="helvetica"
rsr_at_tmYROn=False
rsr_at_trXMinF=1.0
rsr_at_xyDashPatterns=ln_sty
rsr_at_xyLineColors=clr_sng
rsr_at_xyLineThicknesses=ln_thk
rsr_at_xyMarkLineModes=mrk_ln_md
rsr_at_xyMarkerColors=clr_sng
rsr_at_xyMarkerSizeF=mrk_sz
rsr_at_xyMarkers=mrk_typ

; Legend annotations
rsr_lgn_ln=True ; Polyline modifications desired
rsr_lgn_ln_at_gsLineThicknessF=2.0 ; Line thicker
rsr_lgn_txt=True ; Text modifications desired
rsr_lgn_txt_at_txFont="helvetica"
rsr_lgn_txt_at_txFontHeightF=0.015 ; Change text size
rsr_lgn_txt_at_txJust="CenterLeft" ; Text justification

lgn_ln_x1=1.2
lgn_ln_dx=1.0
lgn_ln_x2=lgn_ln_x1+lgn_ln_dx
lgn_ln_x1_x2=(/lgn_ln_x1,lgn_ln_x2/)
lgn_txt_x1=lgn_ln_x2+0.2
lgn_y_top=75.0
lgn_dy=5.0
lgn_y=lgn_y_top-ispan(0,ord_nbr-1,1)*lgn_dy

; Open workstation and plot data
wks=gsn_open_wks("eps","./tst")
plot=gsn_csm_xy(wks,abc,data,rsr)

; Draw legend
lgn_ln=new(ord_nbr,graphic)
do idx=0,ord_nbr-1
     lgn_ln_y1_y2=(/lgn_y(idx),lgn_y(idx)/)
     rsr_lgn_ln_at_gsLineColor=clr_sng(idx)
     rsr_lgn_ln_at_gsLineDashPattern=ln_sty(idx)
     rsr_lgn_ln_at_xyMarkLineMode=mrk_ln_md(idx)
     rsr_lgn_ln_at_xyMarker=mrk_typ(idx)
     rsr_lgn_ln_at_xyMarkerColor=clr_sng(idx)
     rsr_lgn_ln_at_xyMarkerSizeF=mrk_sz(idx)
 
lgn_ln(idx)=gsn_add_polyline(wks,plot,lgn_ln_x1_x2,lgn_ln_y1_y2,rsr_lgn_ln)
; gsn_polyline(wks,plot,lgn_ln_x1_x2,lgn_ln_y1_y2,rsr_lgn_ln)
     gsn_text(wks,plot,dat_sng(idx),lgn_txt_x1,lgn_y(idx),rsr_lgn_txt)
end do; end loop over idx

draw(plot)

frame(wks)

end
***********************************************************************

-- 
Charlie Zender, surname_at_uci.edu, Department of Earth System Science
3228 Croul Hall, UC Irvine, Irvine CA 92697-3100. (949) 824-2987 :)
_______________________________________________
ncl-talk mailing list
ncl-talk_at_ucar.edu
http://mailman.ucar.edu/mailman/listinfo/ncl-talk