| wnsumd_c |
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Table of contents
Procedure
wnsumd_c ( Summary of a double precision window )
void wnsumd_c ( SpiceCell * window,
SpiceDouble * meas,
SpiceDouble * avg,
SpiceDouble * stddev,
SpiceInt * idxsml,
SpiceInt * idxlon )
AbstractSummarize the contents of a double precision window. Required_ReadingWINDOWS KeywordsWINDOWS Brief_I/OVARIABLE I/O DESCRIPTION -------- --- -------------------------------------------------- window I Window to be summarized. meas O Total measure of intervals in window. avg O Average measure. stddev O Standard deviation. idxsml, idxlon O Locations of shortest, longest intervals. Detailed_Input
window is a window containing zero or more intervals.
`window' must be declared as a double precision SpiceCell.
CSPICE provides the following macro, which declares and
initializes the cell
SPICEDOUBLE_CELL ( window, WINDOWSZ );
where WINDOWSZ is the maximum capacity of `window'.
Detailed_Output
meas is the total measure of the intervals in the input
window. This is just the sum of the measures of the
individual intervals.
avg is the average of the measures of the intervals in the
input window.
stddev is the standard deviation of the measures of the
intervals in the input window.
idxsml,
idxlon are the locations of the shortest and longest intervals
in the input window. The shortest interval is
[ SPICE_CELL_ELEM_D( window, idxsml ),
SPICE_CELL_ELEM_D( window, idxsml+1 ) ]
and the longest is
[ SPICE_CELL_ELEM_D( window, idxlon ),
SPICE_CELL_ELEM_D( window, idxlon+1 ) ]
`idxsml' and `idxlon' are both -1 if the input window
contains no intervals.
If `window' contains multiple intervals having the shortest
length, `idxsml' is the index of the first such interval.
Likewise for the longest length.
Indices range from 0 to 2N-2, where N is the number of
intervals in the window.
ParametersNone. Exceptions
1) If `window' has odd cardinality, the error
SPICE(INVALIDCARDINALITY) is signaled by a routine in the call
tree of this routine.
2) Left endpoints of stored intervals must be strictly greater
than preceding right endpoints. Right endpoints must be
greater than or equal to corresponding left endpoints.
Invalid window data are not diagnosed by this routine and may
lead to unpredictable results.
3) If the `window' cell argument has a type other than
SpiceDouble, the error SPICE(TYPEMISMATCH) is signaled.
FilesNone. Particulars
This routine provides a summary of the input window, consisting
of the following items:
- The measure of the window.
- The average and standard deviation of the measures
of the individual intervals in the window.
- The indices of the left endpoints of the shortest
and longest intervals in the window.
All of these quantities are zero if the window contains no
intervals.
Examples
The numerical results shown for these examples 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) Define a window with six intervals, and calculate the
summary for that window.
Example code begins here.
/.
Program wnsumd_ex1
./
#include <stdio.h>
#include "SpiceUsr.h"
int main( )
{
/.
Local parameters.
./
#define WNSIZE 12
/.
Local variables.
./
SpiceDouble avg;
SpiceDouble left;
SpiceDouble meas;
SpiceDouble right;
SpiceDouble stddev;
SPICEDOUBLE_CELL ( window, WNSIZE );
SpiceInt idxlon;
SpiceInt idxsml;
SpiceInt intlon;
SpiceInt intsml;
/.
Validate the window with size WNSIZE and zero elements.
./
wnvald_c ( WNSIZE, 0, &window );
/.
Insert the intervals
[ 1, 3 ] [ 7, 11 ] [ 18, 18 ] [ 23, 27 ] [ 30, 69 ] [ 72, 80 ]
into `window'.
./
wninsd_c ( 1.0, 3.0, &window );
wninsd_c ( 7.0, 11.0, &window );
wninsd_c ( 18.0, 18.0, &window );
wninsd_c ( 23.0, 27.0, &window );
wninsd_c ( 30.0, 69.0, &window );
wninsd_c ( 72.0, 80.0, &window );
/.
Calculate the summary for `window'.
./
wnsumd_c ( &window, &meas, &avg, &stddev, &idxsml, &idxlon );
/.
`idxsml' and `idxlon' refer to the indices of
the SPICE Cell data array.
./
intsml = idxsml/2;
intlon = idxlon /2;
printf( "Measure : %f\n", meas );
printf( "Average : %f\n", avg );
printf( "Standard Dev : %f\n", stddev );
printf( "Index shortest : %d\n", idxsml );
printf( "Index longest : %d\n", idxlon );
printf( "Interval shortest : %d\n", intsml );
printf( "Interval longest : %d\n", intlon );
/.
Output the shortest and longest intervals.
./
wnfetd_c( &window, intsml, &left, &right );
printf( "Shortest interval : [ %f, %f ]\n", left, right );
wnfetd_c( &window, intlon, &left, &right );
printf( "Longest interval : [ %f, %f ]\n", left, right );
return( 0 );
}
When this program was executed on a Mac/Intel/cc/64-bit
platform, the output was:
Measure : 57.000000
Average : 9.500000
Standard Dev : 13.413302
Index shortest : 4
Index longest : 8
Interval shortest : 2
Interval longest : 4
Shortest interval : [ 18.000000, 18.000000 ]
Longest interval : [ 30.000000, 69.000000 ]
2) Let A contain the intervals
[ 1, 3 ] [ 7, 11 ] [ 23, 27 ]
Let B contain the singleton intervals
[ 2, 2 ] [ 9, 9 ] [ 27, 27 ]
The measures of A and B are
(3-1) + (11-7) + (27-23) = 10
and
(2-2) + (9-9) + (27-27) = 0
respectively. Each window has three intervals; thus, the average
measures of the windows are 10/3 and 0. The standard deviations
are
------------------------------------------
| 2 2 2
| (3-1) + (11-7) + (27-23) 2 1/2
| --------------------------- - (10/3) = (8/9)
| 3
\ |
\|
and 0. Neither window has one "shortest" interval or "longest"
interval; so the first ones found are returned: `idxsml' and
`idxlon' are 0 and 2 for A, 0 and 0 for B.
RestrictionsNone. Literature_ReferencesNone. Author_and_InstitutionN.J. Bachman (JPL) J. Diaz del Rio (ODC Space) H.A. Neilan (JPL) W.L. Taber (JPL) I.M. Underwood (JPL) E.D. Wright (JPL) Version
-CSPICE Version 1.1.0, 05-AUG-2021 (JDR)
Changed output argument names "shortest" and "longest" to
"idxsml" and "idxlon" for consistency with other routines.
Edited the header to comply with NAIF standard. Added complete code
example.
Extended description of argument "window" in -Detailed_Input to include
type and preferred declaration method.
Fixed error in documentation of arguments "idxsml" and "idxlon": if the
input window contains no intervals, both are -1 and not zero.
Added entries #1 and #2 in -Exceptions section.
-CSPICE Version 1.0.1, 27-JAN-2009 (EDW)
Corrected argument names shown in Brief I/O list.
"short" to "shortest"; "long" to "longest".
-CSPICE Version 1.0.0, 29-JUL-2002 (NJB) (HAN) (WLT) (IMU)
Index_Entriessummary of a d.p. window |
Fri Dec 31 18:41:15 2021