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Next: ms.getbuffer - Function Up: ms - Tool Previous: ms.fillbuffer - Function


ms.diffbuffer - Function



Package general
Module ms
Tool ms


Differentiate or difference the internal buffer.


Synopsis
diffbuffer(direction, window)


Arguments

direction   choose between time or channel direction
    Allowed: String: TIME or CHANNEL
window   width of averaging window in timeslots or channels
    Allowed: Positive integer


Returns
Record, with statistics over the buffer if all went well



Description
Subtract the previous point from each data point in the buffer (for window=2), or subtract the average over a window (for window>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.



Example
myms:=ms("3C273XC1.MS");
myms.select([antenna1=3]);
myms.fillbuffer("DATA");
myms.diffbuffer("TIME",15)

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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