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How to check if object (variable) is defined in R?
...on of "...is defined". E.g.
> exists("foo")
[1] FALSE
> foo <- 1:10
> exists("foo")
[1] TRUE
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Create a variable name with “paste” in R?
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In my case function eval() works very good. Below I generate 10 variables and assign them 10 values.
lhs <- rnorm(10)
rhs <- paste("perf.a", 1:10, "<-", lhs, sep="")
eval(parse(text=rhs))
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Only detect click event on pseudo-element
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PHP variables in anonymous functions
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answered Jul 10 '12 at 19:31
nickbnickb
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SQL SELECT speed int vs varchar
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Int comparisons are faster than varchar comparisons, for the simple fact that ints take up muc...
What is the difference between native code, machine code and assembly code?
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edited Aug 8 '10 at 12:35
answered Aug 8 '10 at 12:14
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Nested JSON objects - do I have to use arrays for everything?
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edited Jan 20 '10 at 0:47
answered Jan 20 '10 at 0:37
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How to get the name of a class without the package?
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answered Apr 22 '10 at 11:31
BozhoBozho
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How does the following LINQ statement work?
... Sandeep ChauhanSandeep Chauhan
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Is there a portable way to print a message from the C preprocessor?
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answered Sep 30 '10 at 0:24
YouYou
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