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Extract a dplyr tbl column as a vector
Is there a more succinct way to get one column of a dplyr tbl as a vector, from a tbl with database back-end (i.e. the data frame/table can't be subset directly)?
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Reasons for using the set.seed function
Many times I have seen the set.seed function in R, before starting the program. I know it's basically used for the random number generation. Is there any specific need to set this?
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Why can't C++ be parsed with a LR(1) parser?
...tes that:
"C++ grammar is ambiguous,
context-dependent and potentially
requires infinite lookahead to resolve
some ambiguities".
It goes on to give a number of examples (see page 147 of the pdf).
The example is:
int(x), y, *const z;
meaning
int x;
int y;
int *const z;
Compare to:
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How to draw a line in android
Can anybody tell how to draw a line in Android, perhaps with an example?
15 Answers
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What is the default access modifier in Java? [duplicate]
...odifier for a method or an instance variable if I do not state it explicitly?
13 Answers
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Run an OLS regression with Pandas Data Frame
...ict the values of column A from the values in columns B and C. Here is a toy example:
5 Answers
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How do I get the current date and time in PHP?
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The time would go by your server time. An easy workaround for this is to manually set the timezone by using date_default_timezone_set before the date() or time() functions are called to.
I'm in Melbourne, Australia so I have something like thi...
How can the Euclidean distance be calculated with NumPy?
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Use numpy.linalg.norm:
dist = numpy.linalg.norm(a-b)
You can find the theory behind this in Introduction to Data Mining
This works because Euclidean distance is l2 norm and the default value of ord parameter in numpy.linalg.norm ...
How can I change the color of pagination dots of UIPageControl?
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UPDATE:
This answer is 6 years old and very outdated, but it's still attracting votes and comments. Ever since iOS 6.0 you should be using the pageIndicatorTintColor and currentPageIndicatorTintColor properties on UIPageControl.
ORIGINAL ANSWER:
I ...
Python pandas: fill a dataframe row by row
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df['y'] will set a column
since you want to set a row, use .loc
Note that .ix is equivalent here, yours failed because you tried to assign a dictionary
to each element of the row y probably not what you want; converting to a Se...