Calculate the number of channels (elements) in each group.
Array_Type chanspergrp = grpGetChansPerGroup( Array_Type grouping )
This function returnes the number of channels (i.e. elements)
in each group.
The return value is an array whose length equals
that of the input data (the dataArray argument)
and each element within a group contains the same value.
As an example,
grpGetChansPerGroup( [1,-1,1,-1,1,1] )
will return the array
since the groups consist of the first two elements,
then the next two elements, with the last two elements
being un-grouped.
chips> nchan = grpGetChansPerGroup( grp )
The nchan array will contain the number of elements
in each group, as given in the grouping scheme
stored in the grp array.
The nchan array will have the same size as the grp
array. The following code shows
you how you can convert nchan into an array in
which each element corresponds to one group.
chips> i = where( grp == 1 )
chips> nelem = nchan[i]
Here we created an array i whose elements correspond
to those elements in the grp array with a value of 1
(this marks the start of a group). The nelem array is
then created by using this array to extract the
corresponding elements from the ncham array.
It could have been written in one line as:
chips> nelem = nchan[ where( grp == 1 ) ]
chips> x = [0.5:6.0:0.05]
chips> y = 3 + 30 * exp( - (x-2.0)^2 / 0.1 )
chips> ( grp, qual ) = grpNumCounts( y, 15 )
chips> ysum = grpGetGroupSum( y, grp )
chips> nchan = grpGetChansPerGroup( grp )
chips> i = where( grp == 1 and qual == 0 )
chips> xstart = x[i]
chips> yavg = ysum[i] / nchan[i]
Here we take the function
y = 3 + 30 * exp( -(x-2)^2 / 0.1 )
and group it by 15 counts per group.
We then filter the summed array (ysum) so that it
corresponds to only those elements at the start
of a group - the
condition - and for which the quality flag is "good" -
which is given by
This array is divided by the number of elements in each
group to calculate the average value in the group.
Note that the xstart array gives the start position of each
group.
- group
-
grpadaptive,
grpadaptivesnr,
grpbin,
grpbinfile,
grpbinwidth,
grpgetchanspergroup,
grpgetgroupsum,
grpgetgrpnum,
grpmaxslope,
grpminslope,
grpnumbins,
grpnumcounts,
grpsnr
- modules
-
group
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