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[McIDAS #FIP-506235]: Modifying a schema file

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  • Subject: [McIDAS #FIP-506235]: Modifying a schema file
  • Date: Wed, 01 Jun 2016 09:26:18 -0600
Hi Kwan,

re:
> I would like to modify the default ISHP schema to allow acceptance of the
> WMO weather codes similar to the WXC1, WXC2, WXC3, WXC4 in the ISFC
> schema.

OK.  Be aware that you should never modify a system schema unless you are
prepared to deal with a variety of issues from this point forward.  Instead,
the thing to do is to create a new schema, register it in the SCHEMA file
and then use it.

re:
> The end result is for PTDISP to be able to display weather
> symbols given decoded ship observations in an MD file.  (The default ISHP
> does contain WXP but it does not allow weather symbols to be plotted.)

I believe I understand what you want to do.

re:
> What are the necessary steps to go about modifying ISHP to include WXC?

The easiest thing is to:

- convert the existing ISFC schema file into ASCII text (it is in LW format
  in the distribution and always has been)

  LWTODOS DCISFC DCJSFC.txt

  DCJSFC.txt should be created in your McIDAS working directory as defined
  by the MCDATA environment variable.

- edit DCJSFC.txt and make the modifications you want

  Be careful to follow the example entries that you will find in the original
  DCJSFC.txt file created by the LWTODOS conversion.  In particular, make sure
  to rename the schema inside the schema template file.  If you don't, and if
  you are using the ISFC schema, things will get munged!

- register your new schema in the McIDAS SCHEMA file:

  SCHE DCJSFC.txt

- test using the newly modified and registered schema

Review McIDAS User's Guide pages on:

- LSCHE, SCHE, LWTODOS, DOSTOLW

re:
> Thanks again,

No worries.

Cheers,

Tom
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Ticket Details
===================
Ticket ID: FIP-506235
Department: Support McIDAS
Priority: Normal
Status: Closed
===================
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