# [ncl-talk] Wondering why I am getting this dimensions error

Rashed Mahmood rashidcomsis at gmail.com
Wed Nov 27 12:31:24 MST 2019

```Hi Barry,
Obviously, you know what you are doing. However, I still can't get it. What
do you mean by "it should become an array of just 0s and 1s" and most
importantly how could it become an array of 0's and 1s?
Anyway, you can ignore this message, if nothing more to discuss.

On Wed, Nov 27, 2019 at 11:20 AM Barry Lynn <barry.h.lynn at gmail.com> wrote:

> Hi:
>
> Normally, it would be a sum of 2s and 1s, but because I am only doing the
> sum once (for each k), it should becomes an array of  just 0's and  1s.
>
> Originally, I thought if I set a 1 D array equal to the where statement,
> it would sum the 2d array.  To do that, I had to actually sum it (add_q).
>
> Barry
>
> On Wed, Nov 27, 2019 at 8:58 PM Rashed Mahmood <rashidcomsis at gmail.com>
> wrote:
>
>> Sorry for chipping in here, and may be I am wrong but I do not follow the
>> logic:
>>
>> If you do: sum_q :=  where(qs(k,:,:).ge.0.1,sum_q+1,sum_q)
>>
>> The variable "sum_q" would be a 2d array containing *2s* and *1s*. Do
>> you want a sum of 2s and 1s or you want a sum of qs(k,:,:) where it is
>> greater than 0.1?
>>
>>
>>
>>
>>
>>
>>
>> On Wed, Nov 27, 2019 at 10:50 AM Barry Lynn via ncl-talk <
>> ncl-talk at ucar.edu> wrote:
>>
>>> Hi:
>>>
>>> The problem with the previous suggestion was that the sum_q became a 2
>>> dimensional variable..  I needed it to be a 1D variables. I found this out
>>> by using the "function" printVarSummary
>>>
>>> Here is the correct solution for my needs, based on the very helpful
>>> comments up to now.
>>>
>>> Thanks
>>>
>>> (sum_q was defined as a 2d variable -- note: sum_q is not really a sum,
>>> as used here, but defined as 1 whereever qs > 0.1).
>>>
>>>        sum_q = 0
>>>
>>>        sum_q(0,0) = 1 ; just so I don't divide by 0!
>>>
>>>        sum_q =  where(qs(k,:,:).ge.0.1,sum_q+1,sum_q)
>>>
>>>        add_q = sum(sum_q); a 1d variable
>>>
>>>  ;      printVarSummary(qs_1(k))
>>>
>>>   ;     printVarSummary(sum_q)
>>>
>>>
>>>        qs_1(k)  = sum(qs(k,:,:))/add_q+qs_1(k)
>>>
>>> On Wed, Nov 27, 2019 at 8:18 PM Dennis Shea <shea at ucar.edu> wrote:
>>>
>>>> re:   :=
>>>> Yes.
>>>>
>>>> On Wed, Nov 27, 2019 at 10:49 AM Barry Lynn via ncl-talk <
>>>> ncl-talk at ucar.edu> wrote:
>>>>
>>>>> Hi Dave:
>>>>>
>>>>> Thank you for your suggestions.
>>>>>
>>>>> I actually need to sum_q for all elements of the remaining (:,:) 2d
>>>>> array to obtain a single number.
>>>>>
>>>>> I am dividing one number by it.
>>>>>
>>>>> I assume that it is okay to put the := and that I will get the sum
>>>>> over all 2d elements?
>>>>>
>>>>> On Wed, Nov 27, 2019 at 7:40 PM Dave Allured - NOAA Affiliate <
>>>>> dave.allured at noaa.gov> wrote:
>>>>>
>>>>>> "sum_q = 1." defines this variable as scalar.  Then the where
>>>>>> statement attempts to write a 2-D array onto a scalar.  The assignment
>>>>>> statement is not allowed to change dimensions.
>>>>>>
>>>>>> One way to fix this would be to use the reassignment operator ":=",
>>>>>> which IS allowed to change dimensions on assignment.
>>>>>>
>>>>>> Another way to fix this would be to define sum_q as a 2-D array
>>>>>> before the start of the loop.  I suspect that is what you really intended.
>>>>>>
>>>>>>
>>>>>> On Wed, Nov 27, 2019 at 10:22 AM Barry Lynn via ncl-talk <
>>>>>> ncl-talk at ucar.edu> wrote:
>>>>>>
>>>>>>> Hi:
>>>>>>>
>>>>>>> I have some simple code.
>>>>>>>
>>>>>>>       do k = 0,dims3d(0)-1
>>>>>>>
>>>>>>>        qs(k,:,:) = where(qs(k,:,:).lt.0.1,q_null(k,:,:),qs(k,:,:))
>>>>>>>
>>>>>>>        sum_q = 1.
>>>>>>>
>>>>>>>        sum_q =  where(qs(k,:,:).ge.0.1,sum_q+1,sum_q)
>>>>>>>
>>>>>>>        qs_1(k) = sum(qs(k,:,:))/sum_q+qs_1(k)
>>>>>>>
>>>>>>>       end do
>>>>>>>
>>>>>>>
>>>>>>> Why can't I do the "where" sum?
>>>>>>>
>>>>>>>
>>>>>>> fatal:Number of dimensions on right hand side do not match number of
>>>>>>> dimension in left hand side
>>>>>>>
>>>>>>> --
>>>>>>> Barry H. Lynn, Ph.D
>>>>>>> Senior Associate Scientist, Lecturer,
>>>>>>> The Institute of the Earth Science,
>>>>>>> The Hebrew University of Jerusalem,
>>>>>>> Givat Ram, Jerusalem 91904, Israel
>>>>>>> Tel: 972 547 231 170
>>>>>>> Fax: (972)-25662581
>>>>>>>
>>>>>>> C.E.O, Weather It Is, LTD
>>>>>>> Weather and Climate Focus
>>>>>>> http://weather-it-is.com
>>>>>>> Jerusalem, Israel
>>>>>>> Local: 02 930 9525
>>>>>>> Cell: 054 7 231 170
>>>>>>> Int-IS: x972 2 930 9525
>>>>>>>
>>>>>>
>>>>>
>>>>> --
>>>>> Barry H. Lynn, Ph.D
>>>>> Senior Associate Scientist, Lecturer,
>>>>> The Institute of the Earth Science,
>>>>> The Hebrew University of Jerusalem,
>>>>> Givat Ram, Jerusalem 91904, Israel
>>>>> Tel: 972 547 231 170
>>>>> Fax: (972)-25662581
>>>>>
>>>>> C.E.O, Weather It Is, LTD
>>>>> Weather and Climate Focus
>>>>> http://weather-it-is.com
>>>>> Jerusalem, Israel
>>>>> Local: 02 930 9525
>>>>> Cell: 054 7 231 170
>>>>> Int-IS: x972 2 930 9525
>>>>>
>>>>> _______________________________________________
>>>>> ncl-talk mailing list
>>>>> ncl-talk at ucar.edu
>>>>> List instructions, subscriber options, unsubscribe:
>>>>> http://mailman.ucar.edu/mailman/listinfo/ncl-talk
>>>>
>>>>
>>>
>>> --
>>> Barry H. Lynn, Ph.D
>>> Senior Associate Scientist, Lecturer,
>>> The Institute of the Earth Science,
>>> The Hebrew University of Jerusalem,
>>> Givat Ram, Jerusalem 91904, Israel
>>> Tel: 972 547 231 170
>>> Fax: (972)-25662581
>>>
>>> C.E.O, Weather It Is, LTD
>>> Weather and Climate Focus
>>> http://weather-it-is.com
>>> Jerusalem, Israel
>>> Local: 02 930 9525
>>> Cell: 054 7 231 170
>>> Int-IS: x972 2 930 9525
>>>
>>> _______________________________________________
>>> ncl-talk mailing list
>>> ncl-talk at ucar.edu
>>> List instructions, subscriber options, unsubscribe:
>>> http://mailman.ucar.edu/mailman/listinfo/ncl-talk
>>
>>
>
> --
> Barry H. Lynn, Ph.D
> Senior Associate Scientist, Lecturer,
> The Institute of the Earth Science,
> The Hebrew University of Jerusalem,
> Givat Ram, Jerusalem 91904, Israel
> Tel: 972 547 231 170
> Fax: (972)-25662581
>
> C.E.O, Weather It Is, LTD
> Weather and Climate Focus
> http://weather-it-is.com
> Jerusalem, Israel
> Local: 02 930 9525
> Cell: 054 7 231 170
> Int-IS: x972 2 930 9525
>
>
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