If we randomly put \(n(\ge1)\) balls into \(m(\ge1)\) boxes, what is the expectation of the number of empty boxes?
See my neat answer here.
Define Operator in R
One thing I do not like R is that operations on String in R
are not as convenient as in other programming langauges such as Java, Python and Ruby.
In these 3 programming languages,
you can simply use + to concatenate strings while in R you have to use the function …
Abuse of Vector in R
R is a language that is friendly to vector operation, so vector is an important data structure in R. A single data (of basic types, e.g., numeric or character) is essentially a vector of length 1. A matrix or an array in R is essentially a vector. R make …
Tips for VB/VB.net
About String Functions
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The uniform random variables generated by VB is pretty good. At least it's acceptable according to the test in R.
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String functions that return a string can be used with a dollar sign at the end, which is a faster version of the corresponding function.
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The function …