任意两点间斜剖面做法总结【利用GRADS自带函数】

river

海蓝蓝 发表于 2014-11-28 22:50
用来mask掉地形剖面的，难道不就是我说的这个数据吗？
mask不会用。。。。。

maskout有官方文档的。你自己去看看用法http://grads.iges.org/grads/gadoc/gadocindex.html

黑马骑士

请教river，这个ncep地形应该放到哪里？opengrads版本

river

黑马骑士 发表于 2014-12-2 20:46
请教river，这个ncep地形应该放到哪里？opengrads版本

随便你放在哪都行，记得修改ctl 里面的路径就没问题。无论那个grads版本都可以用

黑马骑士

river 发表于 2014-12-3 07:58
随便你放在哪都行，记得修改ctl 里面的路径就没问题。无论那个grads版本都可以用

谢谢，昨晚已经画出来了。顺便请教下，一般把垂直速度放大多少倍再与水平速度合成比较合适呢？

river

黑马骑士 发表于 2014-12-3 08:38
谢谢，昨晚已经画出来了。顺便请教下，一般把垂直速度放大多少倍再与水平速度合成比较合适呢？

个人感觉100倍

email

神贴啊，佩服的五体投地了

Jennifer

我现在就是要画这个图，但是有三个格点中心，举一反三试试看行不行。

海蓝蓝

maskout

maskout(expr,mask)

Wherever the mask values are less than zero, the values in expr are set to the missing data value.

Works with gridded or station data. Where mask values are positive, the expr values are not modified. Thus the result of maskout is data with a possibly increased number of missing data values. The maskout function, in spite of its apparant simplicity, is extremely useful.

Usage Notes

Examples

See the Examples for the const function for a description of using maskout to calculate the percentage of the globe covered by precipitation.
The maskout function can be used to cause part of the data to be ignored while doing another calculation. For example, if we have a land-sea mask, where sea values are negative, and we want to take some areal average of a quantity only over land:
d aave(maskout(p,mask.2),lon=0,lon=360,lat=0,lat=90)
People frequently have trouble using a mask grid, because it is often put into a seperate file, and given some arbitrary date/time and level. Thus, it is often necessary to locally override the dimension environment while using the mask grid:
d aave(maskout(p,mask.2(t=1)),lon=0,lon=360,lat=0,lat=90)
would probably be how Example 2 would have to be expressed in order to work, with the local override of t=1 specified on the mask data. See the documentation on how GrADS evaluates expressions within the dimension environment for more information.

river

海蓝蓝 发表于 2014-12-12 13:27
maskout

maskout(expr,mask)

是不是回复错了？

pangpang1128

感谢分享，学习中