Difference between ids, ims, ips,its

[hiroto]

Often used in physics module
ids, ims, ips, its
I do not understand the difference.

Each definition is
start index for i in domain,
start index for i in memory,
start index for i in patch,
start index for i in tile,
But I don't know what these mean.

Is there anyone who knows?

The reference module is module_surface_driver.F.

 

[Ming Chen]

"ids,, ide, jds, jde" etc. are "domain" sized indexes along the i, j, k directions.

"ims, ime, jms, jme" are "memory" dimensions for arrays.

"ips, ipe, jps, jpe" are computational extent for loops inside most of the WRF physics.

A more detailed description can be found in the website:
http://www2.mmm.ucar.edu/wrf/users/tutorial/201607/software.pdf

 

[hiroto]

Thank you for providing easy-to-understand materials.

For example,
When you want to change the tsk value in the range of x = 1-20 y = 5-15 of the domain by rewriting the contents of the physics module,
Is it correct to use ids = 1, ide = 20, jds = 5, jde = 15 with the if block statement?
Or are there other variable names for x and y?

 

[Ming Chen]

All the indexes in WRF are global, which means that, for example, if you specify iout=20, jout=15, they are the point (20,15) in the model domain.
If you want to change values over a subregion, you can simply add the loop like:

do i = ia, ib
do j = ja, jb
newer(i,j) = xxx
end do
end do

You don't need to worry for the domain decomposition.

 

[hiroto]

I understand. I'm sorry to reply late. Thank you very much.