byteswapped and yrev

[N Jyothi]

While creating and transferring data files from one platform to another, I
was not sure about the right option to be specified in the grads control
file.

Thanks Douglas for the explanation.

Regards - Jyothi

----- Original Message -----
From: "Douglas Clark" <dbcl at CEH.AC.UK>
To: <GRADSUSR at LIST.CINECA.IT>
Sent: Wednesday, February 01, 2006 4:14 PM
Subject: Re: byteswapped and yrev


> I'm not sure I can give you much detail, beyond what's in the web
> documentation, but here are the basics:
>
> 'yrev' means that the data are stored in your file in "north to south"
> order.
> Without yrev, GrADS expects the data to be stored in "south to north"
> order, that is, the southernmost row of data first, then the next
> row...,ending with the northernmost row (eg 90S, 80S, 70S,...,80N,
> 90N).
> With yrev, the northernmost row is stored first (eg 90N, 80N,...).
> GrADS uses yrev when it reads data from the file, so that it knows to
> reverse the row order before plotting.
>
> 'byteswapped' means that the order of the bytes in the data file is not
> the default for your computer. Again, GrADS uses this when it reads data
> in. If you only ever use GrADS on the same computer that you use to
> write the data files, chances are you won't ever need byteswapped. (The
> little_endian and big_endian options are argueably more useful, as the
> ctl files can then be used on any machine, regardless of byte order).
>
> Often you don't need either of the yrev or byteswapped options - it
> just depends on your data files.
>
> Doug
>
>
> >>> njyothi at CDAC.IN 01/02/2006 10:03:24 >>>
> Hello Grads Users
>         I haven't entirely understood the 'yrev' and 'byteswapped'
> options
> in grads. Can someone pls explain these options in detail?
>
> Jyothi
>
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