Re: Maximum Covariance Analysis

> fatal:svdcov: The rightmost dimension of the homlft/hetlft arrays must
> be the same as the leftmost dimension of x, and the leftmost dimension

Is "ncolf1" equal to nlat*mlon ?
Is "ncolf2" equal to nlat1*mlon ?

leonardo.silva@cptec.inpe.br wrote:
> Hi all again
>
> I'm trying to use the svdcov function but it don't work well.
>
> ncl 0> load "$NCARG_ROOT/lib/ncarg/nclscripts/csm/gsn_code.ncl"
> ncl 1> load "$NCARG_ROOT/lib/ncarg/nclscripts/csm/gsn_csm.ncl"
> ncl 2> load "$NCARG_ROOT/lib/ncarg/nclscripts/csm/contributed.ncl"
> ncl 3>
> ncl 4>
> ncl 5>
> ncl 6> latS = -21.
> ncl 7> latN = 32.
> ncl 8> lonL = -74.
> ncl 9> lonR = 15.
> ncl 10>
> ncl 11> nsvd = 2
> ncl 12> ncolf1 = 471128
> ncl 13> ncolf2 = 471128
> ncl 14>
> ncl 15>
> ncl 16> homlft = new((/nsvd,ncolf1/),float)
> ncl 17> hetlft = new((/nsvd,ncolf1/),float)
> ncl 18> homrgt = new((/nsvd,ncolf2/),float)
> ncl 19> hetrgt = new((/nsvd,ncolf2/),float)
> ncl 20>
> ncl 21> f1 = addfile ("EH5_OM_20C_2_TSURF_DETRENDRUNMEAN.nc", "r")
> ncl 22> tsm = f1->tsurf
> ncl 23>
> ncl 24> f2 = addfile ("EH5_OM_20C_2_U10M_DETRENDRUNMEAN.nc", "r")
> ncl 25> u = f2->u10
> ncl 26>
> ncl 27> dimtsm = dimsizes(tsm)
> ncl 28> ntim = dimtsm(0)
> ncl 29> nlat = dimtsm(1)
> ncl 30> mlon = dimtsm(2)
> ncl 31>
> ncl 32> dimu10 = dimsizes(u)
> ncl 33> ntim1 = dimu10(0)
> ncl 34> nlat1 = dimu10(1)
> ncl 35> mlon1 = dimu10(2)
> ncl 36>
> ncl 37> T = onedtond( ndtooned(tsm), (/ntim,nlat*mlon/))
> ncl 38> U = onedtond( ndtooned(u), (/ntim1,nlat1*mlon1/))
> ncl 39>
> ncl 40> covar = svdcov(T,U,nsvd,homlft,hetlft,homrgt,hetrgt)
>
> and I got it like answer:
> fatal:svdcov: The rightmost dimension of the homlft/hetlft arrays must
> be the same as the leftmost dimension of x, and the leftmost dimension
> must be nsvx
> fatal:Execute: Error occurred at or near line 40
>
> I think the problem is in the space allocate to the matrices
>
> The two fields used in the calculus are shown below:
>
> dimensions:
> lon = 47 ;
> lat = 28 ;
> time = UNLIMITED ; // (358 currently)
> variables:
> double lon(lon) ;
> lon:long_name = "longitude" ;
> lon:units = "degrees_east" ;
> lon:standard_name = "longitude" ;
> double lat(lat) ;
> lat:long_name = "latitude" ;
> lat:units = "degrees_north" ;
> lat:standard_name = "latitude" ;
> double time(time) ;
> time:units = "day as %Y%m%d.%f" ;
> time:calendar = "proleptic_gregorian" ;
> float u10(time, lat, lon) ;
> u10:long_name = "10m u-velocity" ;
> u10:units = "m/s" ;
> u10:code = 165 ;
> u10:table = 128 ;
> u10:grid_type = "gaussian" ;
>
> dimensions:
> lon = 47 ;
> lat = 28 ;
> time = UNLIMITED ; // (358 currently)
> variables:
> double lon(lon) ;
> lon:long_name = "longitude" ;
> lon:units = "degrees_east" ;
> lon:standard_name = "longitude" ;
> double lat(lat) ;
> lat:long_name = "latitude" ;
> lat:units = "degrees_north" ;
> lat:standard_name = "latitude" ;
> double time(time) ;
> time:units = "day as %Y%m%d.%f" ;
> time:calendar = "proleptic_gregorian" ;
> float tsurf(time, lat, lon) ;
> tsurf:long_name = "surface temperature" ;
> tsurf:units = "K" ;
> tsurf:code = 169 ;
> tsurf:table = 128 ;
> tsurf:grid_type = "gaussian" ;
>
> May I ask if anyone can help me?
>
> I appreciate any help.
>
> Thanks a lot
>
> Leonardo
> = = = = = = = =
> Quoting Dennis Shea <shea@ucar.edu>:
>
>> http://www.ncl.ucar.edu/Document/Functions/Built-in/svdcov.shtml
>>
>> function svdcov (
>> x [*][*] : numeric,
>> y [*][*] : numeric,
>> nsvd : integer,
>> homlft [*][*] : numeric,
>> hetlft [*][*] : numeric,
>> homrgt [*][*] : numeric,
>> hetrgt [*][*] : numeric
>> )
>>
>>
>> You took
>>> tempsup = tsm( time|:, lat|:, lon|: ) ; 3d
>>> uwnd = u( time|:, lat|:, lon|: ) ; 3d
>>
>> which are 3-dimensional, and then invoked svdcov
>>
>>> covar = svdcov(tempsup(time|:, tsurf|:),uwnd(time|:, \
>>> tsurf|:),nsvd,homlft,hetlft,homrgt,hetrgt)
>>
>> with
>> tempsup(time|:, tsurf|:) ; 2d
>> and
>> uwnd(time|:, tsurf|:) ; 2d
>>
>>
>> Where did "tsurf" come from?
>>
>> A transformation from 3d-to-2d does not happen automatically.
>> The user must do this.
>>
>> dimu = dimsizes( u )
>> ntim = dimu(0)
>> nlat = dimu(1)
>> mlon = dimu(2)
>>
>> T = onedtond( ndtooned(tempsup), (/ntim,nlat*mlon/)) ; 2D
>> U = onedtond( ndtooned( uwnd ), (/ntim,nlat*mlon/)) ; 2D
>>
>> covar = svdcov(T,U,nsvd,homlft,hetlft,homrgt,hetrgt)
>>
>>
>> ===
>> If you are new to NCL I suggest you read the mini-language manual.
>> Later, if interested in the graphics, the min-graphics manual.
>>
>> http://www.ncl.ucar.edu/Document/Manuals/
>>
>> They are pdf. They do have color so if you have a color
>> printer, I suggest using it.
>>
>> Good luck
>>
>> leonardo.silva@cptec.inpe.br wrote:
>>> Hi all,
>>>
>>> I'm a new ncl user and I would like to construct an Atlantic
>>> Meridional Mode (AMM) Index like done by ERSL
>>> (http://www.esrl.noaa.gov/psd/data/timeseries/monthly/AMM/). I have
>>> to apply a Maximum Covariance Analysis to a SST field (left field)
>>> and the zonal and meridional 10m wind (right field) through a
>>> Singular Value Decomposition (SVD). I have to extract the first
>>> left (SST) and right (winds) maps resulting from singular value
>>> decomposition of the covariance matrix. The AMM time series is
>>> calculated via projecting SST or the 10m wind field. onto the
>>> spatial structure resulting from the MCA.
>>>
>>> I tried to construct that thing using the scrpt below:
>>>
>>> load "$NCARG_ROOT/lib/ncarg/nclscripts/csm/gsn_code.ncl"
>>> load "$NCARG_ROOT/lib/ncarg/nclscripts/csm/gsn_csm.ncl"
>>> load "$NCARG_ROOT/lib/ncarg/nclscripts/csm/contributed.ncl"
>>>
>>>
>>>
>>> latS = -21.
>>> latN = 32.
>>> lonL = -74.
>>> lonR = 15.
>>>
>>> nsvd = 2
>>> ncolf1 = 1316
>>> ncolf2 = 1316
>>>
>>> homlft = new((/nsvd,ncolf1/),float)
>>> hetlft = new((/nsvd,ncolf1/),float)
>>> homrgt = new((/nsvd,ncolf2/),float)
>>> hetrgt = new((/nsvd,ncolf2/),float)
>>>
>>> f1 = addfile ("EH5_OM_20C_2_TSURF_DETRENDRUNMEAN.nc", "w")
>>> tsm = f1->tsurf
>>> f1!0 = "time"
>>> f2 = addfile ("EH5_OM_20C_2_U10M_DETRENDRUNMEAN.nc", "w")
>>> u = f2->u10
>>> tempsup = tsm( time|:, lat|:, lon|: )
>>> uwnd = u( time|:, lat|:, lon|: )
>>>
>>> covar = svdcov(tempsup(time|:, tsurf|:),uwnd(time|:,
>>> tsurf|:),nsvd,homlft,hetlft,homrgt,hetrgt)
>>>
>>> asciiwrite("mca.dat", covar(0,:))
>>>
>>> and I got it like answer:
>>>
>>> ncl 28> covar = svdcov(tempsup(time|:, tsurf|:),uwnd(time|:,
>>> tsurf|:),nsvd,homlft,hetlft,homrgt,hetrgt)
>>> fatal:Number of subscripts do not match number of dimensions of
>>> variable,(2) Subscripts used, (3) Subscripts expected
>>> fatal:Execute: Error occurred at or near line 28
>>>
>>> I have more one question:
>>>
>>> How can I put the wind (u+v) components onto a one variable? Have I
>>> to sum the u and v.nc files?
>>>
>>> Regards
>>>
>>> Leonardo
>>>
>>> _______________________________________________
>>> ncl-talk mailing list
>>> List instructions, subscriber options, unsubscribe:
>>> http://mailman.ucar.edu/mailman/listinfo/ncl-talk
>
>
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Received on Mon Nov 30 19:10:24 2009