关于NCL画垂直剖面图

lleoiu · 发表于 2013-10-22 09:55:50

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本帖最后由 lleoiu 于 2017-9-14 11:27 编辑

2017.9.14:
在NCL的6.2之后的版本中，gsn_csm_pres_hgt_vector函数里默认的vcMapDirection=False
“This resource now defaults to False for this function in NCL V6.2.0.”
http://www.ncl.ucar.edu/Document ... es_hgt_vector.shtml

用NCL画垂直剖面图的时候，总是感觉水平方向上的矢量要比垂直方向上的大（垂直方向上已经乘上了－100），并且画出来的垂直方向总是与GRADS画的方向相反。如图1（NCL），图2（grads)。

fig1

这是NCL默认的设置。
The problem is that by default NCL maps the vector direction into the underlying coordinate space. This is good when drawing on a map projection, but for vertical plots where the two coordinate axes have different units that have very different numerical spacing between the coordinate values it leads to distortion. There is a simple fix, which is to set the resource vcMapDirection to False.

加上res@vcMapDirection = False这一设置之后，画的图与GRADS一样，垂直方向上只需乘上100即可。如图3.

begin
f2 = addfile("/data/NCEP-2.5/monthly/pressure/vwnd.mon.mean.nc","r")
f3 = addfile("/data/NCEP-2.5/monthly/pressure/omega.mon.mean.nc","r")
vwnd1 = short2flt(f2->vwnd(7,0:11,{0:90},{95:110}))
vwnd11 = dim_avg_n_Wrap(vwnd1,2)
omega1 = short2flt(f3->omega(7,0:11,{0:90},{95:110})) ;{45:20}
omega11 = dim_avg_n_Wrap(omega1,2)
w = omega11*100.
wks = gsn_open_wks("eps","vv5")
gsn_define_colormap(wks,"gui_default")
res = True
res@cnLinesOn = False
res@cnLineLabelsOn = False
res@cnInfoLabelOn = False
res@tmXTOn = False ; and right tickmarks.
res@tmYROn = False
res@vcRefMagnitudeF = 5.
res@vcRefAnnoString1On = True
res@vcRefAnnoString1 = "5m/s"
res@vcRefAnnoOrthogonalPosF = -1.095
res@vcRefAnnoString2On = False
res@vcRefLengthF = 0.027
res@vcGlyphStyle = "LineArrow
res@vcMinDistanceF = 0.008
res@vcMapDirection = False
res@vpWidthF = 0.75
res@vpHeightF = 0.6
res@tiMainFontHeightF = 0.02
res@gsnLeftString = ""
res@gsnRightString = ""
res@tiYAxisString = "p/hPa"
res@tmYRMode = "Automatic"
res@tmXBMode = "Explicit"
plot = gsn_csm_pres_hgt_vector(wks,vwnd11,vwnd11,w,res)
end

复制代码

kongfeng0824 · 发表于 2013-10-22 13:59:33

谢谢分享

freekiller · 发表于 2013-10-22 14:12:37

收藏了，一定会用到。谢谢

小拱猪Solo · 发表于 2013-10-24 11:14:38

这个好厉害收藏了！

guigui · 发表于 2013-11-23 13:03:59

非常实用！

lemondaodao · 发表于 2013-11-23 21:16:37

看看，谢谢

吕丽 · 发表于 2013-12-2 12:26:26

刚好试试看

宁小才 · 发表于 2013-12-26 19:54:52

收藏了，一定会用到。谢谢

小胖子 · 发表于 2014-1-4 16:10:58

请问楼主有没有试过用NCL画垂直剖面图时，加地形进去？？

lleoiu · 发表于 2014-1-6 11:32:38

小胖子发表于 2014-1-4 16:10

登录/注册后可看大图

请问楼主有没有试过用NCL画垂直剖面图时，加地形进去？？

没有诶。还没有画过加地形的剖面图

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