20010222: MCIDAS-X 7.7 RAOB cross sections

>From: alan anderson <address@hidden>
>Organization: St. Cloud State
>Keywords: 200102221913.f1MJDPL26671 McIDAS-X 7.7x XSECT XSECTG mapurx.for

Alan,

>We have noticed that when plotting a raob cross section (using 
>default values from MCGUI,  Display,  Obs., Raob Cross Sect. )
>the cross section plots, but the small inset map does not locate
>the "line" or stations in the correct place.
>
>For example, a default cross section lat bounds  30 55 and 
>longitude bounds 105 105,  the inset map shows the station
>line through  MO and IA  which is offset well to the east
>of the desired longitude.
>
>This same problems shows up on both  ver. 7.700 and 7.704 for me.
>
>This problem does NOT appear on our terminals witn ver. 7.613.

Thanks for alerting me to this problem.  This bug is an unexpected
side effect of the 7.7 upgrade of the MAP command.  What is happening
is the following:

o the new MAP command uses context tables to define map backgrounds;
  default projections; map colors; line widths; etc.

o I sent out the core context file MAP.CORE with the default projection
  set to CONF:

In ~mcidas/data/MAP.CORE::

 ...
# History: 20000924 - Changed default projection to CONF

GLOBAL  PROJECTION=    CONF \
 ...

o both XSECT and XSECTG call the subroutine MAPURX (mapurx.for) to
  draw maps in the upper right hand corner of the cross section display.

  They both are assuming that the map will be drawn in MERCator projection,
  so the PRO= keyword is not being included on the MAP command line that
  MAPURX executes.  Since the default projection was changed to CONF,
  the MAP invocation in MAPURX is expanded to something that was
  unintended (something like MAP DEF col LAT=... ... LON=... ... PRO=CONF')
  The addition of PRO=CONF is incorrect for the LAT,LON boundaries
  of the intended MAP.  This is why the cross section line AND map are
  incorrect.

There are two solutions to the problem:

as the user 'mcidas', do:

1) change the default MAP projection in MAP.CORE

cd ~mcidas/data
<edit MAP.CORE>
change:

GLOBAL  PROJECTION=    CONF \

to:

GLOBAL  PROJECTION=    MERC \

2) update the XSECT and XSECTG executables with a fix in mapurx.for:

cd ~mcidas/mcidas7.7/src
ftp ftp.unidata.ucar.edu
  <user> anonymous
  <pass> your_email_address
  cd pub/mcidas
  get mapurx.for
  quit
touch mapurx.for
make xsect.k xsectg.k
rm ~/bin/xsect.k ~/bin/xsectg.k
ln xsect.k xsectg.k ~/bin

For now, I recommend the second option over the first (even though I
may go back and change the default PROJECTION for MAP to MERC for
the next addendum).  This must be done on every machine where McIDAS-X
is installed.

>I got the same problem when specifying other latitude and longitude
>ranges using MCGUI on a terminal with 7.70x.

Right, the problem is in mapurx.for.

>Thanks

Sorry for the oversight on my part.

Tom