Re: The error from "dim_avg_n".

Dear Hoffman,

Thanks for your explanation. That's true.

The dimensional sizes of input array must be larger than the averaging dimensional sizes.

Actually, I have met another error: "fatal:dim_avg_n: Input dimension sizes must be monotonically increasing, can't continue " when i tried to perform averaging for a 4d array on its first (0) and third (2) dimensions. And that's due to that averaging dimensions must be close each other.

Anyway, these usages of dim_avg_n are limited.

Best Regards,

Huang Ping





发件人： Hoffman Cheung
发送时间： 2010-09-29 21:00:19
收件人： HUANG, Ping
抄送：
主题： Re: [ncl-talk] The error from "dim_avg_n".
 
Dear Huang Ping,

  The fourth example of this function illustrates the case when the function performs averaging on the first and second dimensions (subscripts 0 and 1) of a four-dimensional variable. But the variable in your trail contains two dimensions only, that's why it does not work.


Best Regards,
Hoffman


2010/9/29 HUANG, Ping <ph0007@ustc.edu>

Hi all,

Here I report a error from the function "dim_avg_n".

In the online document http://www.ncl.ucar.edu/Document/Functions/Built-in/dim_avg_n.shtml, dim_avg_n can perform average in multi-dimension as in example 4:

Example 4
Let z be defined as z(time,lev,lat,lon). Compute the time average at each latitude/longitude grid point.
    zAvg = dim_avg_n(z, (/0,1/)) ; ==> zAvg(nlat,nlon)

If metadata is desired use:
    zAvg = dim_avg_n_Wrap(z, (/0,1/)) ; ==> zAvg(nlat,nlon)

However, the error occurs when I try to use the multi-dimension average as above. And I test a simple example as following.


 NCAR Command Language Version 5.1.1
 The use of this software is governed by a License Agreement.
 See http://www.ncl.ucar.edu/ for more details.
ncl 0> a = (/ (/1,2,3/),(/4,5,6/) /)
ncl 1> print(a)
Variable: a
Type: integer
Total Size: 24 bytes
            6 values
Number of Dimensions: 2
Dimensions and sizes: [2] x [3]
Coordinates:
(0,0) 1
(0,1) 2
(0,2) 3
(1,0) 4
(1,1) 5
(1,2) 6
ncl 2> temp = dim_avg_n( a , (/0,1/) )
fatal:NclReturnValue: Incomplete information to create return value from builtin function
fatal:Execute: Error occurred at or near line 2

ncl 3> print (dim_avg_n( a , 1 ))
(0) 2
(1) 5

What's the correct usage of multi-dimension average in dim_avg_n?

Best Regards,

Thanks

Huang Ping



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Received on Wed Sep 29 08:37:11 2010