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Identify if a string is a number
...you can discard the out parameter
var isNumeric = int.TryParse("123", out _);
The var s can be replaced by their respective types!
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Mutable vs immutable objects
...entations do not necessarily need to copy (clone) the entire collection in order to provide that immutability. The simplest example is the stack implemented as a singly linked list and the push/pop operations. You can reuse all of the nodes from the previous collection in the new collection, adding ...
How to compute the similarity between two text documents?
... package, computing cosine similarities is as easy as
from sklearn.feature_extraction.text import TfidfVectorizer
documents = [open(f) for f in text_files]
tfidf = TfidfVectorizer().fit_transform(documents)
# no need to normalize, since Vectorizer will return normalized tf-idf
pairwise_similarity ...
How to see which flags -march=native will activate?
...ere (I guess): echo | gcc-6 -dM -E - -march=sandybridge | grep AVX #define __AVX__ 1 but cache sizes do seem absent.
– rogerdpack
Jul 14 '16 at 0:37
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Populating a ListView using an ArrayList?
... onCreate(Bundle saveInstanceState) {
setContentView(R.layout.your_layout);
lv = (ListView) findViewById(R.id.your_list_view_id);
// Instanciating an array list (you don't need to do this,
// you already have yours).
List<String> your_array_list ...
Trimming a huge (3.5 GB) csv file to read into R
...with readLines. This piece of a code creates csv with selected years.
file_in <- file("in.csv","r")
file_out <- file("out.csv","a")
x <- readLines(file_in, n=1)
writeLines(x, file_out) # copy headers
B <- 300000 # depends how large is one pack
while(length(x)) {
ind <- grep("^[^...
Async image loading from url inside a UITableView cell - image changes to wrong image while scrollin
...URLSession sharedSession] dataTaskWithURL:url completionHandler:^(NSData * _Nullable data, NSURLResponse * _Nullable response, NSError * _Nullable error) {
if (data) {
UIImage *image = [UIImage imageWithData:data];
if (image) {
dispatch_async(dispatch_...
How does Go compile so quickly?
...instructions in binary form. Extra work (but not much) needs to be done in order to transform the text into binary.
The Go compiler targets only a small number of CPU architectures, while the GCC compiler targets a large number of CPUs
Compilers which were designed with the goal of high compilation ...
Good MapReduce examples [closed]
... for a million records would take a while, and this would only increase in order of magnitute when the complexity of the query increases.
Map Reduce provides a cluster based implementation where data is processed in a distributed manner
Here is a wikipedia article explaining what map-reduce is a...
Remove Select arrow on IE
... browser, it is easy to set the same background image for the drop-down in order to have the same arrow.
To do so, you have to reset the browser's default style for the select tag and set new background rules (like suggested before).
select {
/* you should keep these firsts rules in place to m...