***---关于gsnAddCyclic和tfDoNDCOverlay参数的使用说明-------***
只要数据没有覆盖整个地球,则gsnAddCyclic应设置为 False------
在使用原生网格数据(如模型结果)的时候tfDoNDCOverlay要设置成 False
;---关于gsnAddCyclic--------------------------------------------------------------------------
;---https://www.ncl.ucar.edu/Document/Graphics/Resources/gsn.shtml------
--总的好理解,只要数据没有覆盖整个地球,则此资源应设置为 False。----
;-----------------------------------------------------------------------------------------------------
gsnAddCyclic
For geo-referenced data, a longitude cyclic point is added as a default to ensure a gap is not plotted at the Greenwich Meridian. This resource only applies to gsn_csm plotting routines that overlay data on a map.
This resource should be set to False if your data already has a cyclic point added, or if your data does not cover the whole globe to start with. This resource defaults to True for many gsn_csm_xxxx scripts that create contour, vector, or streamline plots, unless the function can determine automatically that this is not cyclic data.
对于地理参考数据,默认添加一个经度循环点,以确保不会在格林威治子午线处绘制间隙。 此资源仅适用于在地图上叠加数据的 gsn_csm 绘图例程。
如果您的数据已经添加了循环点,或者如果您的数据没有覆盖整个地球,则此资源应设置为 False。 对于许多创建等高线、矢量或流线图的 gsn_csm_xxxx 脚本,此资源默认为 True,除非该函数可以自动确定这不是循环数据。
Default: dynamic
;---关于tfDoNDCOverlay--------------------------------------------------------------------------------------------------
;---http://ncl.ucar.edu/Document/Graphics/Resources/tf.shtml----------------------------------------------
;---http://ncl.ucar.edu/Applications/native.shtml-----------------------------------------------------------------
--在使用原生网格数据(如模型结果)的时候要设置成 False。要注意投影的问题。----------------
**************************************************************************************************************
;---------------------------------------------------------------------------------------------------------------------------------
WARNING
Is your data on a native grid? A native grid is a grid that is on a particular map projection.
In order to plot the data correctly over a map, you must know the exact map projection and all its parameters. You will then plot the data over this map projection without needing to do any kind of mathematical transformation.
警告
您的数据是否在原生格网上? 原生格网是位于特定地图投影上的格网。
为了在地图上正确绘制数据,您必须知道准确的地图投影及其所有参数。
然后,您将在此地图投影上绘制数据,而无需进行任何类型的数学转换。
To plot native grids, you must set the resource tfDoNDCOverlay = True, so that the data doesn't go through a mathematical transformation to be overlaid on the map. Additionally, you commonly want to set the resource mpLimitMode="Corners" to specify the area of the map to zoom in on. This resource must be accompanied by resources for setting the four corners of the map area to view: mpLeftCornerLatF, mpLeftCornerLonF, mpRightCornerLatF, and mpRightCornerLonF.
要绘制原生网格,您必须设置资源 tfDoNDCOverlay = True,这样数据就不会经过数学变换来覆盖在地图上。 此外,您通常希望设置资源 mpLimitMode="Corners" 以指定要放大的地图区域。 此资源必须附有用于设置地图区域的四个角以查看的资源:mpLeftCornerLatF、mpLeftCornerLonF、mpRightCornerLatF 和 mpRightCornerLonF。
pmTickMarkDisplayMode = "Always" turns on the automatic tickmarks.
If your data comes with 2D lat/lon arrays, you then have the option of plotting it on a different map projection. In this case, you do not want to set tfDoNDCOverlay (it is False by default). Instead, you will need to set the special lat2d/lon2d attributes. See example 3 on the Ice Model page, example 1 on the EASE page, or example 3 on the Raster contouring page,
如果您的数据带有 2D lat/lon 数组,那么您可以选择将其绘制在不同的地图投影上。 在这种情况下,您不想设置 tfDoNDCOverlay(默认为 False)。 相反,您需要设置特殊的 lat2d/lon2d 属性。 请参见 Ice Model 页面上的示例 3,EASE 页面上的示例 1,或 Raster contouring 页面上的示例 3,
Lambert conformal native grids have been given their own page.