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Table of contents
Procedure
BODVRD ( Return d.p. values from the kernel pool )
SUBROUTINE BODVRD ( BODYNM, ITEM, MAXN, DIM, VALUES )
Abstract
Fetch from the kernel pool the double precision values
of an item associated with a body.
Required_Reading
KERNEL
NAIF_IDS
Keywords
CONSTANTS
Declarations
IMPLICIT NONE
INCLUDE 'zzctr.inc'
CHARACTER*(*) BODYNM
CHARACTER*(*) ITEM
INTEGER MAXN
INTEGER DIM
DOUBLE PRECISION VALUES ( * )
Brief_I/O
VARIABLE I/O DESCRIPTION
-------- --- --------------------------------------------------
BODYNM I Body name.
ITEM I Item for which values are desired. ('RADII',
'NUT_PREC_ANGLES', etc. )
MAXN I Maximum number of values that may be returned.
DIM O Number of values returned.
VALUES O Values.
Detailed_Input
BODYNM is the name of the body for which ITEM is requested.
BODYNM is case-insensitive, and leading and trailing
blanks in BODYNM are not significant. Optionally, you
may supply the integer ID code for the object as an
integer string. For example both 'MOON' and '301' are
legitimate strings that indicate the moon is the body
of interest.
ITEM is the item to be returned. Together, the NAIF ID
code of the body and the item name combine to form a
kernel variable name, e.g.,
'BODY599_RADII'
'BODY401_POLE_RA'
The values associated with the kernel variable having
the name constructed as shown are sought. Below
we'll take the shortcut of calling this kernel variable
the "requested kernel variable."
Note that ITEM *is* case-sensitive. This attribute
is inherited from the case-sensitivity of kernel
variable names.
MAXN is the maximum number of values that may be returned.
The output array VALUES must be declared with size at
least MAXN. It's an error to supply an output array
that is too small to hold all of the values associated
with the requested kernel variable.
Detailed_Output
DIM is the number of values returned; this is always the
number of values associated with the requested kernel
variable unless an error has been signaled.
VALUES is the array of values associated with the requested
kernel variable. If VALUES is too small to hold all
of the values associated with the kernel variable, the
returned values of DIM and VALUES are undefined.
Parameters
None.
Exceptions
1) If the input body name cannot be translated to an ID code,
and if the name is not a string representation of an integer
(for example, '399'), the error SPICE(NOTRANSLATION) is
signaled.
2) If the requested kernel variable is not found in the kernel
pool, the error SPICE(KERNELVARNOTFOUND) is signaled.
3) If the requested kernel variable is found but the associated
values aren't numeric, the error SPICE(TYPEMISMATCH) is
signaled.
4) If the dimension of VALUES indicated by MAXN is too small to
contain the requested values, the error SPICE(ARRAYTOOSMALL)
is signaled. The output array VALUES must be declared with
sufficient size to contain all of the values associated with
the requested kernel variable.
5) If the input dimension MAXN indicates there is more room
in VALUES than there really is---for example, if MAXN is
10 but values is declared with dimension 5---and the dimension
of the requested kernel variable is larger than the actual
dimension of VALUES, then this routine may overwrite
memory. The results are unpredictable.
Files
None.
Particulars
This routine simplifies looking up PCK kernel variables by
constructing names of requested kernel variables and by
performing error checking.
This routine is intended for use in cases where the maximum number
of values that may be returned is known at compile time. The
caller fetches all of the values associated with the specified
kernel variable via a single call to this routine. If the number
of values to be fetched cannot be known until run time, the
lower-level routine GDPOOL should be used instead. GDPOOL supports
fetching arbitrary amounts of data in multiple "chunks."
This routine is intended for use in cases where the requested
kernel variable is expected to be present in the kernel pool. If
the variable is not found or has the wrong data type, this
routine signals an error. In cases where it is appropriate to
indicate absence of an expected kernel variable by returning a
boolean "found flag" with the value .FALSE., again the routine
GDPOOL should be used.
Examples
The numerical results shown for this example may differ across
platforms. The results depend on the SPICE kernels used as
input, the compiler and supporting libraries, and the machine
specific arithmetic implementation.
1) Retrieve the radii of the Earth from the kernel pool, using
both 'RADII' and 'radii' as the item name to return. Since
the ITEM variable possesses case sensitivity, the later case
should fail. Trap the error and print it to the output.
Use the PCK kernel below to load the required triaxial
ellipsoidal shape model for the Earth.
pck00008.tpc
Example code begins here.
PROGRAM BODVRD_EX1
IMPLICIT NONE
C
C Local parameters.
C
INTEGER NVALS
PARAMETER ( NVALS = 3 )
C
C Local variables.
C
DOUBLE PRECISION VALUES (NVALS)
INTEGER DIM
C
C Load a PCK.
C
CALL FURNSH ( 'pck00008.tpc' )
C
C When the kernel variable
C
C BODY399_RADII
C
C is present in the kernel pool---normally because a PCK
C defining this variable has been loaded (as is the case
C here)---the call
C
CALL BODVRD ( 'EARTH', 'RADII', 3, DIM, VALUES )
C
C returns the dimension and values associated with the
C variable 'BODY399_RADII'
C
WRITE(*,'(A,3F10.3)') 'EARTH RADII: ', VALUES
C
C The call
C
CALL BODVRD ( 'earth', 'RADII', 3, DIM, VALUES )
C
C will produce the same results since the case of the
C input argument BODYNM is not significant.
C
WRITE(*,'(A,3F10.3)') 'earth RADII: ', VALUES
C
C The call
C
CALL BODVRD ( '399', 'RADII', 3, DIM, VALUES )
C
C will also produce the same results since strings
C containing integer codes are accepted
C by this routine.
C
WRITE(*,'(A,3F10.3)') '''399'' RADII: ', VALUES
C
C The ITEM variable possesses case sensitivity. This
C call should cause an error.
C
CALL BODVRD ( 'EARTH', 'radii', 3, DIM, VALUES )
WRITE(*,'(A,3F10.3)') 'EARTH radii: ', VALUES
END
When this program was executed on a Mac/Intel/gfortran/64-bit
platform, the output was:
EARTH RADII: 6378.140 6378.140 6356.750
earth RADII: 6378.140 6378.140 6356.750
'399' RADII: 6378.140 6378.140 6356.750
============================================================***
Toolkit version: N0066
SPICE(KERNELVARNOTFOUND) -- The Variable Was not Found in th***
Pool.
The variable BODY399_radii could not be found in the kernel ***
A traceback follows. The name of the highest level module i***
BODVRD
Oh, by the way: The SPICELIB error handling actions are USER-
TAILORABLE. You can choose whether the Toolkit aborts or co***
when errors occur, which error messages to output, and where***
the output. Please read the ERROR "Required Reading" file, ***
the routines ERRACT, ERRDEV, and ERRPRT.
============================================================***
Warning: incomplete output. 8 lines extended past the right
margin of the header and have been truncated. These lines are
marked by "***" at the end of each line.
Note that, usually, the last call will cause a
SPICE(KERNELVARNOTFOUND) error to be signaled, because this
call will attempt to look up the values associated with a
kernel variable of the name
'BODY399_radii'
Since kernel variable names are case sensitive, this
name is not considered to match the name
'BODY399_RADII'
which normally would be present after a text PCK
containing data for all planets and satellites has
been loaded.
Restrictions
None.
Literature_References
None.
Author_and_Institution
N.J. Bachman (JPL)
J. Diaz del Rio (ODC Space)
B.V. Semenov (JPL)
W.L. Taber (JPL)
I.M. Underwood (JPL)
Version
SPICELIB Version 1.2.1, 27-AUG-2021 (JDR)
Edited the header to comply with NAIF standard.
Added complete example code based on the existing fragments.
Removed note about GDPOOL being entry point of POOL from
$Particulars section.
SPICELIB Version 1.2.0, 19-SEP-2013 (BVS)
Updated to save the input body name and ZZBODTRN state counter
and to do name-ID conversion only if the counter has changed.
SPICELIB Version 1.1.0, 22-JUL-2004 (NJB)
Updated to use BODS2C.
SPICELIB Version 1.0.0, 23-FEB-2004 (NJB) (BVS) (WLT) (IMU)
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Fri Dec 31 18:36:00 2021