[ncl-talk] Coherence analysis

[Soma Roy]

I am trying with the attached script as you said. But getting constant
values..

Summary of the input data along with intermediate steps are as follows;

Variable: dslp
Type: double
Total Size: 93312000 bytes
            11664000 values
Number of Dimensions: 3
Dimensions and sizes:   [time | 45] x [lat | 360] x [lon | 720]
Coordinates:
            time: [25748..41819]
            lat: [-89.75..89.75]
            lon: [-179.75..179.75]
Number Of Attributes: 5
  long_name :   diurnal temperature range
  units :       degrees Celsius
  _FillValue :  9.969209968386869e+36
  missing_value :       9.969209968386869e+36
  correlation_decay_distance :   750

Variable: dslp2
Type: double
Total Size: 259200 bytes
            32400 values
Number of Dimensions: 2
Dimensions and sizes:   [time | 45] x [lon | 720]
Coordinates:
            time: [25748..41819]
            lon: [-179.75..179.75]
Number Of Attributes: 6
  _FillValue :  9.969209968386869e+36
  long_name :   diurnal temperature range
  units :       degrees Celsius
  correlation_decay_distance :   750
  missing_value :       9.969209968386869e+36
  average_op_ncl :      dim_avg_n over dimension(s): lat

Variable: tslp2
Type: double
Total Size: 259200 bytes
            32400 values
Number of Dimensions: 2
Dimensions and sizes:   [time | 45] x [lon | 720]
Coordinates:
            time: [25748..41819]
            lon: [-179.75..179.75]
Number Of Attributes: 6
  _FillValue :  9.969209968386869e+36
  long_name :   precipitation
  units :       mm/month
  correlation_decay_distance :   450
  missing_value :       9.969209968386869e+36
  average_op_ncl :      dim_avg_n over dimension(s): lat

Variable: pr
Type: double
Total Size: 5760 bytes
            720 values
Number of Dimensions: 1
Dimensions and sizes:   [720]
Coordinates:
Number Of Attributes: 20
  yslope :      1e+36
  ylag1 :       1e+36
  yvaro :       1e+36
  yvari :       1e+36
  yavei :       1e+36
  xslope :      1e+36
  xlag1 :       1e+36
  xvaro :       1e+36
  xvari :       1e+36
  xavei :       1e+36
  coher_probability :   (    0,    0,    0,    0 )
  bw :  1e+36
  phase :       <ARRAY of 22 elements>
  coher :       <ARRAY of 22 elements>
  quspc :       <ARRAY of 22 elements>
  cospc :       <ARRAY of 22 elements>
  frq : <ARRAY of 22 elements>
  spcy :        <ARRAY of 22 elements>
  spcx :        <ARRAY of 22 elements>
  _FillValue :  9.969209968386869e+36

Variable: h1
Type: double
Total Size: 176 bytes
            22 values
Number of Dimensions: 1
Dimensions and sizes:   [22]
Coordinates:

Variable: h2
Type: double
Total Size: 176 bytes
            22 values
Number of Dimensions: 1
Dimensions and sizes:   [22]
Coordinates:


All values are constant like;
 yslope :      1e+36
  ylag1 :       1e+36
  yvaro :       1e+36
  yvari :       1e+36
and so on..

Please let me know where I am doing wrong/missing something.

Thanking you,
Soma

On Wed, Mar 20, 2019 at 8:07 PM Soma Roy <somaroy892 at gmail.com> wrote:

> Can you kindly give me a hint how to use the function over a variable (say
> 3D variable as time, lat, lon) as you said?
>
> Thanking you,
> Soma
>
> On Wed, Mar 20, 2019, 20:00 Dennis Shea <shea at ucar.edu wrote:
>
>> For sure, these were created with NCL. However, I am not sure how these
>> were created.
>>
>> NCL's *specxy_anal*
>> <http://www.ncl.ucar.edu/Document/Functions/Built-in/specxy_anal.shtml>
>>
>> could have been applied *at each longitude* (loop over longitudes) and
>> the results stored in arrays:
>>
>>    COHER(frq,lon), PHASE(frq,lon), COSPC(frq,lon),  QUSPC(frq,lon)
>>
>> ===
>> Other, possibly useful, links:
>>
>> *http://www.ncl.ucar.edu/Applications/space_time.shtml*
>> <http://www.ncl.ucar.edu/Applications/space_time.shtml>
>>
>> *http://www.ncl.ucar.edu/Applications/mjoclivar.shtml*
>> <http://www.ncl.ucar.edu/Applications/mjoclivar.shtml>
>> *Example 11*
>> ====
>>
>> Good luck
>>
>> On Wed, Mar 20, 2019 at 2:42 AM Soma Roy <somaroy892 at gmail.com> wrote:
>>
>>> Hello,
>>>
>>> I am trying to calculate Coherence, Cospectrum, Quadrature and phase
>>> between two variables (two signals).
>>>
>>> Is there any function available in ncl to plot like below attached
>>> figure for the above?
>>>
>>> Please kindly inform me.
>>>
>>> Thanking you,
>>> Soma
>>> _______________________________________________
>>> ncl-talk mailing list
>>> ncl-talk at ucar.edu
>>> List instructions, subscriber options, unsubscribe:
>>> http://mailman.ucar.edu/mailman/listinfo/ncl-talk
>>>
>>
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