From: Bithi De <bde_at_nyahnyahspammersnyahnyah>

Date: Tue Aug 13 2013 - 14:07:28 MDT

Date: Tue Aug 13 2013 - 14:07:28 MDT

Hi,

Thanks Dennis for the reply.

Let me explain my question clearly.

* I have rectilinear grid.

* I have U-component and V-component at each grid point , with print

variable summary like this: (where 12= no. of months and 32= no. of

years)

Variable: Qvv

Type: float

Total Size: 16146432 bytes

4036608 values

Number of Dimensions: 4

Dimensions and sizes: [12] x [32] x [lon | 144] x [lat | 73]

Coordinates:

lon: [ 0..357.5]

lat: [90..-90]

Number Of Attributes: 1

_FillValue : 9.96921e+36

Variable: Quu

Type: float

Total Size: 16146432 bytes

4036608 values

Number of Dimensions: 4

Dimensions and sizes: [12] x [32] x [lon | 144] x [lat | 73]

Coordinates:

lon: [ 0..357.5]

lat: [90..-90]

Number Of Attributes: 1

_FillValue : 9.96921e+36

* I want to calculate line integration along the east, west boundary

of an area for u component and line integration along the south and

north boundary of an area for v component.

I tried like the following:

re = 6.37122e06

rad = 4.0* atan(1.0) / 180.0

con = re * rad

clat = cos(lat * rad) ; cosine of latitude

dlon = (lon(2) - lon(1))

dlat = (lat(2) - lat(1))

dx = con * dlon * clat ; dx at each latitude

dy = con * dlat ; dy is constant

dx1 = conform(Quu,dx,3)

dx1!3 = "lat"

dx1!2 = "lon"

dx1&lat = lat

dx1&lon = lon

printVarSummary(dx1)

printVarSummary(dy)

;***********************************************************************************

; transport across the boundary of the region

;***********************************************************************************

Qu1 = Quu(:,:,{270},{60:80}) ;quu component value across east

boundary at longitude 270

printVarSummary (Qu1)

Qu2 = Quu(:,:,{357},{60:80}) ;quu component value across west

boundary at longitude 357.5

printVarSummary (Qu2)

Qv1 = Qvv(:,:,{270:357},{60}) ;Qvv component across

south boundary at latitude 60

Qv2 = Qvv(:,:,{270:357},{80}) ;Qvv component across

north boundary at latitude 80

printVarSummary (Qv1)

printVarSummary (Qv2)

dx_1=dx1(:,:,{270:357},{60})

dx_2=dx1(:,:,{270:357},{80})

printVarSummary (dx_1)

printVarSummary (dx_2)

L = sum((Qv1*dx_1)+Qu2*dy+(Qv2*dx_2)+Qu1*dy)

For calculating L, I am getting an error like this:

fatal:Plus: Dimension size, for dimension number 2, of operands does

not match, can't continue

Did I calculate dx and dy in wrong way? What should be the right approach?

Thanks for your time.

Bithi

On 8/12/13, Dennis Shea <shea@ucar.edu> wrote:

*> Hi Bithi,
*

*>
*

*> This is offline. Respond to ncl-talk@ucar.edu only
*

*>
*

*> I hesitate to answer because I am very busy and I do
*

*> not have a lot of time to answer ncl-talk questions.
*

*>
*

*> What type of grid do you have? rectilinear or curvilinear?
*

*>
*

*> What have *you* tried? We at ncl-talk sometimes feel people
*

*> want us to write the code for them. We do not have the time.
*

*>
*

*>
*

*>
*

*> <= left
*

*>
*

*> + + + + 60
*

*>
*

*> + + 50
*

*> |
*

*> down + + lat up 40
*

*>
*

*> + + 30
*

*>
*

*> + + + + 20
*

*>
*

*> lon =>
*

*>
*

*> 130 140 150 160
*

*>
*

*> You have U and V at each grid point. Usually, you must go
*

*> counter clockwise around for the circulation theorm.
*

*>
*

*> U(time,lat,lon), V(time,lat,lon)
*

*>
*

*> Here is a crude approach for a rectilinear grid.
*

*>
*

*>
*

*> C = sum( U(:,{20},{130:160})*dx({20}) \
*

*> +V(:,{20:60},{160}) *dy) \
*

*> +U(:,{60},{130:160})*dx(60) \
*

*> +V(:,{20:60},{130}) +dy )
*

*>
*

*> C(ntim)
*

*>
*

*>
*

*> Please ask your advisor or a colleague.
*

*>
*

*>
*

*> On 8/9/13 6:02 PM, Bithi De wrote:
*

*>> Hi All,
*

*>> Is it possible to calculate line integration using NCL? I need to
*

*>> calculate line integration along each boundary of an area.
*

*>>
*

*>> Thanks .
*

*>> Bithi
*

*>>
*

*>
*

-- Bithi De Graduate Student , Research Assistant International Arctic Research Center , University of Alaska Fairbanks Fairbanks , Alaska -99775 USA _______________________________________________ ncl-talk mailing list List instructions, subscriber options, unsubscribe: http://mailman.ucar.edu/mailman/listinfo/ncl-talkReceived on Tue Aug 13 14:07:37 2013

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