1.2.1.0 ms.diffbuffer

ms.diffbuffer - Function

1.2.1 Differentiate or difference the internal buffer.
Description

Subtract the previous point from each data point in the buffer (for window equal 2), or subtract the average over a window (for window greater than 2) from each point. The window can be in the time / row direction or the frequency / channel direction. The input data can be float or complex but the output is always float. The function returns statistics over the buffer: median for each time and channel, the average absolute deviation from the median in time and channel direction and over all pixels.

Arguments


Inputs
direction	choose between time or channel direction: TIME or CHANNEL
	allowed:	string
	Default:
window	width of averaging window in timeslots or channels; integer greater than 0
	allowed:	int
	Default:

Returns
anyrecord

Example

ms.open("3C273XC1.MS")
ms.select({’antenna1’:[3]})
ms.fillbuffer("DATA")
ms.diffbuffer("TIME",15)
# {’aad’: array([[ 0.58959275],
#       [ 0.20988081],
#       [ 0.15907532],
#       [ 0.58837521]]),
# ’median’: array([[ 2.67179847],
#       [ 0.32471114],
#       [ 0.37952924],
#       [ 2.60897708]])}

We open the MS for reading, select a subset and then read the DATA, FLAG and FLAG_ROW column, we then subtract the average over a 15 point time-window from each data point.

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This code is available under the terms of the GNU General Public Lincense