[DISPLAY\]STATISTIC [DataCube [FirstPlane [LastPlane]]
[/EDGE Margin] [/NOISE VarNoise]
Compute some basic statistics (min, max, mean, rms,...) on the specified
DataCube buffer (default: CLEAN) and planes (default: variables FIRST
and LAST). The current polygon or mask (see commands SUPPORT and MASK)
is used to define the area on which the pixels are to be taken into ac-
count, except when /EDGE 0 is mentionned.
In addition to Min and Max, the command prints 3 noise numbers:
- the rms inside the current support (whose value depends on the source
strength and structure)
- the rms outside of the support (a good estimate of the effective
noise), returned in variable STAT_NOISE.
- the theoretical thermal noise (that would be the expected noise unless
the data is dynamic range limited, or unless the weights were
not set properly)
Caution: Statistics on primary-beam corrected images (SKY) cannot be
properly computed in this way, because the noise is non uniform.
Subsections
Gildas manager
2023-06-01