Description:
Given an array of I,J coordinates calculate the histogram of all points onto this grid of size NX
∗ NY.
Just tells you how many data points there are per cell. Returns the histogram and the highest value in
the histogram
Invocation
CALL SURFLIB_HISTOGRAM_GRID (N_PTS, NX, NY, USEDATA, IN_DATA,
IN_QUALITY, BADBIT, IJ, GRID, IMAX, JMAX, NMAX, STATUS )
Arguments
N_PTS =
INTEGER (Given)
Number of I,J pairs supplied
NX = INTEGER (Given)
Size of X
dimension
NY = INTEGER (Given)
Size of Y dimension
USEDATA = LOGICAL (Given)
If TRUE the histogram takes bad data points into account by not including them in the
histogram. If false the straight histogram of the I,J’s is constructed.
IN_DATA(N_PTS) = REAL
(Given)
Input data
IN_QUALITY(N_PTS) = BYTE (Given)
Input quality
BADBIT
= BYTE (Given)
Bad bits mask for quality array
IJ ( 2, N_PTS ) = INTEGER (Given)
Positions of each point (I,J) in output grid
GRID (NX, NY) = INTEGER (Given & Returned)
Histogram. Note that array is not cleared by this routine leaving the possibility that the
routine can be called multiple times to include more than one data set.
IMAX = INTEGER
(Returned)
I position of maximum [first one encountered]
JMAX = INTEGER (Returned)
J
position of maximum [first one encountered]
NMAX = INTEGER (Returned)
Maximum
value in histogram
STATUS = INTEGER (Given & Returned)
Global Status
Notes:
-
If USEDATA is TRUE the data and quality array are used so that bad pixels can be identified and not
included into the histogram of positions.
-
GRID is not initialised by this routine
-
A warning error is raised if the bounds of the histogram are exceeded. It is up to the caller to decide
whether this is a fatal error.
Copyright
Copyright ©1995,1996,1997,1998,1999 Particle Physics and
Astronomy Research Council. All Rights Reserved.