CALL HDIFFB (ID1,ID2,TOL,NBINS,CHOPT,NBAD*,DIFFS*)
Action: Compare two histograms, bin by bin. For each bin, return the probability that the contents are from the same distribution. For details of the method see below.
The comparison may be done between two 1-dimensional histograms, two 2-dimensional histograms, or between two profile histograms.
A and C.
A and C.ID1, ID2 are a pair of 1-D, 2-D, or profile
histograms booked with the same number of bins.
S and C, TOL
is a number between 0 and 1 which
represents the smallest probability considered as an acceptable
match.
TOL=0.05 will cause DIFFS to reject the
bin as bad if there is less than a 5% probability the
two bins came from the same distribution.
Under option A, TOL is the degree of precision of
match required for the test to be considered as passed.
TOL=2.0
means that a data bin differing from the reference mean by
less than 2.0 times the reference error is compatible.
DIFFS below.
S and C options,
in 1- and 2-dimensional histograms,
the means are adjusted for the
relative numbers of entries (including any overflow or
underflow bins requested) in ID1 and ID2.
No adjustment is ever made for profile histograms.
O option is used, this is automatic.
U option uses this automatically.
R, but for the Y-Axis.
L for the Y-Axis.
TOL and
DIFFS.
ID1)
as perfectly describing the true distribution.
Calculates the probability that the data
(from ID2) was produced from that distribution.
For 1- or 2-dimensional histograms, the Poisson
mean is deduced from ID1.
For profile histograms, the test assumes a Gaussian
with mean and standard deviation given by the ID1.
The C option should be used when comparing data
to a function, a well-known reference, or a
calibration distribution.
C test, except that
TOL and DIFFS are in terms of the number
of standard deviations, rather probability.
The test is on the number of standard deviations by
which the data from ID2 deviates from the mean.
Both the mean and the standard deviation are deduced
from ID1.
Error bars must be on for this option.
This forbids overflow bins, underflow bins, and
2-dimensional histograms.
The A option ignores bins with zero contents
in reference histogram.
S option, ignores bins with zero
contents in either histogram.
For the C and A option, ignores bins
with zero contents in the reference histogram.
The default action is to consider all
bins as significant.
S
option (statistical comparison), ignores underflow
and overflow bins, and automatically corrects for the
difference in entries between ID1 and ID2.
TOL and CHOPT.
S and C, deviations for option A).
Results are passed back in the form:
DIFFS(NX) for no over or underflow or
DIFFS(0:NX+1),
for overflow and/or underflow.
DIFFS(NX,NY) or DIFFS(0:NX+1, 0:NY+1).