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help for ^with^                                               (STB-40: dm52)
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Executing a command on a subset of data
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To execute a command on a subset of the data

	^with^ [varlist] [^if^ exp] [^in^ range] [^, nos^ave] ^:^  stata_cmd


Description
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^with^ temporarily drops all but a subset of the data and carries out the 
stata_cmd on the kept data. Any new variables or changes to the subset of the 
data resulting from the stata_cmd will be saved together with the original 
data. Essentially ^with^ does "keep [if] [in]" followed by "keep [varlist]".

^with^ is useful when one has a very large data set and the stata_cmd creates
many temporary variables. It can also be used with "home-made" programs that
do not handle "if" and "in" properly.

^nosave^ leaves the data unchanged after execution of the stata_cmd. The 
default is to combine any new variables created or changes made by stata_cmd
with the original data.

Examples
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	. ^with y x if group==3: running y x, gen(yfit)^
	. ^with meas* in 14001/15000: for meas*: replace @@=@@+1^


Author
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      Peter Sasieni
      Imperial Cancer Research Fund
      London
      email: p.sasieni@@icrf.icnet.uk


Also See
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    STB:  STB-40 dm52