**Previous message:**Sylvia Murphy: "new version of emacs mode available"**Messages sorted by:**[ date ] [ thread ] [ subject ] [ author ]

Hi. I had a question about equivalent sample size and ftest.

I created variables sst1(lat,lon,time) and sst2(lat,lon,time),

and applied a low-pass filter to them. Then I calculated their

variances. For land pts. I use the FillValue of 1e+35.

Now, I want to determine if their variances are significantly

different using the ftest. I included my approach below.

However, the equiv_sample_size command leads to this error:

==>SLATEC/NCL: DGAMMA:

ANSWER LT HALF PRECISION BECAUSE X TOO NEAR NEGATIVE INTEGER: NERR=

1: LEVEL= 1

==>SLATEC/NCL: DBETAI: P AND/OR Q IS LE ZERO: NERR= 2: LEVEL=

2

==>SLATEC/NCL: DLBETA: BOTH ARGUMENTS MUST BE GT ZERO: NERR= 1

: LEVEL= 2

==>SLATEC/NCL: DGAMMA: X IS A NEGATIVE INTEGER: NERR= 4: LEVEL=

2

Previously, I did the same thing for surface air temperature without any errors.

Any idea what is wrong here? Thanks.

Mike

**********************

xEqv = equiv_

sample_size (sst1, 0.1,0)

yEqv = equiv_sample_size (sst2, 0.1,0)

gwt = latGauWgt (128, "lat", "gaussian weights", "dimension_less ")

xN = wgt_areaave (xEqv, gwt, 1., 0)

yN = wgt_areaave (yEqv, gwt, 1., 0)

alpha=new((/128,128/),float)

alpha = 100.*(1. - ftest(var1,xN,var2,yN,0))

alpha!0="lat"

alpha!1="lon"

alpha&lat=lat

alpha&lon=lon

alpha@_FillValue=1e+35

alpha=mask(alpha,oro,0)

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