Functions which perform aggregating operations on array-valued cells.
The functions in this class such as mean
, sum
,
maximum
etc can only be used on values which are already arrays.
In most cases that means on values in table columns which are declared
as array-valued. FITS and VOTable tables can have columns which contain
array values, but other formats such as CSV cannot.
There is also a set of functions named array
with various
numbers of arguments, which let you assemble an array value from a list
of scalar numbers. This can be used for instance to get the mean of
a set of three magnitudes by using an expression like
"mean(array(jmag, hmag, kmag))
".
sum( array )
array
is not a numeric array, null
is returned.array
(Object): array of numbersarray
mean( array )
array
is not a numeric array, null
is returned.array
(Object): array of numbersarray
variance( array )
array
is not a numeric array,
null
is returned.array
(Object): array of numbersarray
stdev( array )
array
is not a numeric array,
null
is returned.array
(Object): array of numbersarray
minimum( array )
array
is not a numeric array, null
is returned.array
(Object): array of numbersarray
maximum( array )
array
is not a numeric array, null
is returned.array
(Object): array of numbersarray
median( array )
array
is not a numeric array, null
is returned.array
(Object): array of numbersarray
quantile( array, quant )
quant
value;
values of 0, 0.5 and 1 give the minimum, median and maximum
respectively. A value of 0.99 would give the 99th percentile.array
(Object): array of numbersquant
(floating point): number in the range 0-1 deterining which quantile
to calculatequant
size( array )
array
is not an array, zero is returned.array
(Object): arrayarray
count( array )
array
is not an array, zero is returned.array
(Object): array (may or may not be numeric)array
array( x1 )
x1
(floating point): array element 1array( x1, x2 )
x1
(floating point): array element 1x2
(floating point): array element 2array( x1, x2, x3 )
x1
(floating point): array element 1x2
(floating point): array element 2x3
(floating point): array element 3array( x1, x2, x3, x4 )
x1
(floating point): array element 1x2
(floating point): array element 2x3
(floating point): array element 3x4
(floating point): array element 4array( x1, x2, x3, x4, x5 )
x1
(floating point): array element 1x2
(floating point): array element 2x3
(floating point): array element 3x4
(floating point): array element 4x5
(floating point): array element 5array( x1, x2, x3, x4, x5, x6 )
x1
(floating point): array element 1x2
(floating point): array element 2x3
(floating point): array element 3x4
(floating point): array element 4x5
(floating point): array element 5x6
(floating point): array element 6array( x1, x2, x3, x4, x5, x6, x7 )
x1
(floating point): array element 1x2
(floating point): array element 2x3
(floating point): array element 3x4
(floating point): array element 4x5
(floating point): array element 5x6
(floating point): array element 6x7
(floating point): array element 7array( x1, x2, x3, x4, x5, x6, x7, x8 )
x1
(floating point): array element 1x2
(floating point): array element 2x3
(floating point): array element 3x4
(floating point): array element 4x5
(floating point): array element 5x6
(floating point): array element 6x7
(floating point): array element 7x8
(floating point): array element 8