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960517: xdrposix_putlong() segmentation fault problems

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  • Subject: 960517: xdrposix_putlong() segmentation fault problems
  • Date: Fri, 17 May 96 09:37:22 -0600
Magnus,

>Date: Fri, 17 May 1996 11:15:27 +0200 
>From: Magnus Weis <address@hidden>
>Organization: . 
>To: Steve Emmerson <address@hidden>
>Subject: 960513: xdrposix_putlong() segmentation fault problems 
>Keywords: 199605091033.AA23012

In the above message you wrote:

...
>  > I think the problem is the last line:
>  > 
>  >     call ncvpt(ncid, ncv, nc2cor, nc2cnt, xi, errno)
>  > 
>  > According to the above code, you're trying to write the following array:
>  > 
>  >     REAL xi(IMAX+1,record)
>  > 
>  > into the netCDF dataset beginning at coordinates (1,record).
>  > Unfortunately, the array `xi' doesn't appear to be dimensioned properly
>  > (indeed, it doesn't appear to be an array at all -- merely a scalar
>  > variable).
>  > 
>  > Also, the `t' variable requires that a DOUBLEPRECISION variable be used
>  > in any NCVPT1 call.  The one you are using appears to be only REAL.
>  > 
> 
> Sorry for causing some missunderstanding. I did not show you all my
> declarations. Here they are:
> 
>       float*8 t
>       float*8 xi(0:IMAX)
> 

If the array xi() is dimensioned as above, then you're trying to write
more data than you have.  The relevant section of your code is

    ncv = ncvid(ncid, 'xi', errno)
    nc2cor(1) = 1
    nc2cor(2) = record
    nc2cnt(1) = IMAX + 1
    nc2cnt(2) = nc2cor(2)       ! problem here
    call ncvpt(ncid, ncv, nc2cor, nc2cnt, xi, errno)

Because of the values in the `nc2cnt' array, the netCDF library
expects that the `xi' array in the call to ncvpt() is dimensioned
xi(IMAX+1,record) -- and it will try to write all (IMAX+1)*record
elements.  The more records you write, the greater the `record' index
will be and the larger the netCDF library will expect the `xi' array to
be.

I suspect that you should use the following code:

    ncv = ncvid(ncid, 'xi', errno)
    nc2cor(1) = 1
    nc2cor(2) = record
    nc2cnt(1) = IMAX + 1
    nc2cnt(2) = 1               ! change here
    call ncvpt(ncid, ncv, nc2cor, nc2cnt, xi, errno)

The above code will write one `xi' record per call -- which is what you
want, I suspect.

--------
Steve Emmerson   <address@hidden>