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From: Ping Y. <pin...@gm...> - 2007-09-05 07:18:47
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Hi,
I checked the manual and briefly searched the mailing list but did not
find this... Is there a table-like data type with rows as events and
columns as attributes that I can make plots with? This is called
"ntuple" in the high energy physics community.
Let me illustrate with an example. Assume that an event consists of 3
attributes (x, y, t). With N events we have a table of N x 3 data
items. Assume that the data items are read from a file "xyt.dat".
d = Table("xyt.dat")
d.plot("x", "t") # make a plot of x vs. t, N points are drawn
d.plot("x") # make a histogram plot of x, N entries in the histogram
d.plot("x", "y < 3") # make a histogram plot of x where y is less than 3.
# that is, only {x[i] | y[i] < 3} are used to make the histogram
If there is no existing modules for this I'll go ahead write one. :)
cheers,
Ping
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