[ncl-talk] XY Plot with Precip vs Time

[Adam Phillips]

Hi Melissa,
There are numerous ways to go about it, including setting the
tmXBMode/tmXBValues/tmXBLabels
<https://www.ncl.ucar.edu/Applications/tickmarks.shtml#ex2> resources. In
this particular case though, it is likely easiest to just modify the
specified x-axis values in the plot call. Try changing this:
plot1=gsn_csm_xy(wks,pr&time,pr(:,0,0),res)
to this:
plot1=gsn_csm_xy(wks,ispan(1856,1890,1),pr(:,0,0),res)

If you want to change the labels themselves you will have to use the
tmXBMode/tmXBValues/tmXBLabels resources. The values input to tmXBValues
must be in the range of values specified in your x-axis input in the plot
call. For example, this will work:

res at tmXBMode = "Explicit"
res at tmXBValues = (/1860,1870,1880,1890/)
res at tmXBLabels =  res at tmXBValues
plot1=gsn_csm_xy(wks,ispan(1856,1890,1),pr(:,0,0),res)

but this will not:
res at tmXBMode = "Explicit"
res at tmXBValues = (/1860,1870,1880,1890/)
res at tmXBLabels =  res at tmXBValues
plot1=gsn_csm_xy(wks,pr&time,pr(:,0,0),res)

Finally, if you set tmXBMode = "Explicit" you will lose the minor tick
marks. To get them back, set tmXBMinorValues.

Hope that helps!
Adam



On Wed, Nov 16, 2022 at 4:38 AM Melissa Lazenby via ncl-talk <
ncl-talk at mailman.ucar.edu> wrote:

> Dear All NCL Users
>
> I am having trouble displaying my x-axis correctly for an XY plot with
> precip anomalies vs time.
> Below is the figure and code:
>
>
> I just would like to have my x-axis represent my time data which is in
> years from 1856-1890.
>
> Any help would be greatly appreciated.
>
> ;************************************************
> ; Concepts illustrated:
> ;   - Drawing a xyplot
> ;************************************************
> load "$NCARG_ROOT/lib/ncarg/nclscripts/csm/gsn_code.ncl"
> load "$NCARG_ROOT/lib/ncarg/nclscripts/csm/gsn_csm.ncl"
> ;************************************************
> begin
> ;************************************************
> ; variable and file handling
> ;************************************************
>   in  =
> addfile("/mnt/geog/ml382/ml382_sals000408_home_dir/melsicz/mpwapwa/ENSMEAN/pr_Amon_ENSMEAN_historical_mpwapwa_1856-1890_NDJFMA_NEW_ANOM_YMONMEAN.nc","r")
>
>
>  pr = in->pr(:,0,:,:)
>
>  print(pr)
>
> ;************************************************
> ; plotting
> ;************************************************
>   wks  = gsn_open_wks("X11","Figure_Mpwapwa_20CR")                 ; Opens
> a ps file
>
>   res                          = True
>   res at gsnMaximize              = True
>   res at tiXAxisString             = "Years 1856-1890 (NDJFMA)"       ;
> x-axis label
>   res at tiYAxisString             = "Precipitation Anomaly"     ; y-axis
> label
>    res at xyLineLabelsOn            = True              ; no contour line
> labels
>   ;res at trXMinF                   =  1856              ; min level
>   ;res at trXMaxF                   =  1890            ; max level
>   res at xyLineThicknessF          = 4.0
>    res at lgLineThicknessF           = 2.0
>
>   res at gsnDraw             = False              ; do not draw the plot
>   res at gsnFrame            = False
>   ;res at pmLegendDisplayMode    = "Always"   ; Display a legend.
>
>   res at pmLegendParallelPosF = 1.25 ; move units right
>   res at pmLegendOrthogonalPosF = -0.9 ; move units down
>   res at lgBoxMinorExtentF       = 0.3
>   res at pmLegendWidthF          = 0.1
>   res at lgLabelFontHeightF      = 0.015     ; Change the font size
>   res at pmLegendHeightF         = 0.2
>
> res at gsnXYBarChart = True
>  res at xyLineColors           = (/"blue", "red"/)
> res at tiMainString = "CMIP5 ENSMEAN Precipitation Anomalies over Mpwapwa"
>  res at gsnYRefLine  = 0.              ; reference line
>
>
> plot1=gsn_csm_xy(wks,pr&time,pr(:,0,0),res)
>
>  draw(plot1)
>  frame(wks)
>
> end
>
> Kindest Regards
> Melissa
>
> Dr. Melissa Lazenby
> Lecturer in Climate Change
> Department of Geography
> Chichester 1 C150
> University of Sussex
>
> *"Education is the most powerful weapon which you can use to change the
> world" Nelson Mandela*
>
>
> _______________________________________________
> ncl-talk mailing list
> ncl-talk at mailman.ucar.edu
> List instructions, subscriber options, unsubscribe:
> https://mailman.ucar.edu/mailman/listinfo/ncl-talk
>


-- 
Adam Phillips
Associate Scientist IV, Climate Analysis Section
Climate and Global Dynamics Laboratory
National Center for Atmospheric Research
www.cgd.ucar.edu/staff/asphilli/

<http://www.cgd.ucar.edu/staff/asphilli>
-------------- next part --------------
An HTML attachment was scrubbed...
URL: <https://mailman.ucar.edu/pipermail/ncl-talk/attachments/20221116/c328c9bf/attachment.htm>
-------------- next part --------------
A non-text attachment was scrubbed...
Name: image.png
Type: image/png
Size: 57655 bytes
Desc: not available
URL: <https://mailman.ucar.edu/pipermail/ncl-talk/attachments/20221116/c328c9bf/attachment.png>
-------------- next part --------------
A non-text attachment was scrubbed...
Name: Outlook-v1qhdcap.png
Type: image/png
Size: 24937 bytes
Desc: not available
URL: <https://mailman.ucar.edu/pipermail/ncl-talk/attachments/20221116/c328c9bf/attachment-0001.png>