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Cluster analysis in R: determine the optimal number of clusters
...ewbie in R, I'm not very sure how to choose the best number of clusters to do a k-means analysis. After plotting a subset of below data, how many clusters will be appropriate? How can I perform cluster dendro analysis?
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How to extract numbers from a string in Python?
I would extract all the numbers contained in a string. Which is the better suited for the purpose, regular expressions or the isdigit() method?
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Update value of a nested dictionary of varying depth
I'm looking for a way to update dict dictionary1 with the contents of dict update wihout overwriting levelA
24 Answers
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Does “\d” in regex mean a digit?
I found that in 123 , \d matches 1 and 3 but not 2 . I was wondering if \d matches a digit satisfying what kind of requirement? I am talking about Python style regex.
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Accessing dict keys like an attribute?
I find it more convenient to access dict keys as obj.foo instead of obj['foo'] , so I wrote this snippet:
27 Answers
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How to sum all the values in a dictionary?
Let's say I have a dictionary in which the keys map to integers like:
9 Answers
9
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How fast is D compared to C++?
I like some features of D, but would be interested if they come with a
runtime penalty?
8 Answers
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Incrementing a date in JavaScript
I need to increment a date value by one day in JavaScript.
16 Answers
16
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Speed up the loop operation in R
...e a big performance problem in R. I wrote a function that iterates over a data.frame object. It simply adds a new column to a data.frame and accumulates something. (simple operation). The data.frame has roughly 850K rows. My PC is still working (about 10h now) and I have no idea about the runt...
Is D a credible alternative to Java and C++? [closed]
Is the D language a credible alternative to Java and C++? What will it take to become a credible alternative? Should I bother learning it? Does it deserve evangelizing?
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