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EF Migrations: Rollback last applied migration?
...some clarification to this thread:
Update-Database -TargetMigration:"name_of_migration"
What you are doing above is saying that you want to rollback all migrations UNTIL you're left with the migration specified. Thus, if you use GET-MIGRATIONS and you find that you have A, B, C, D, and E, then u...
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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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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Is it more efficient to copy a vector by reserving and copying, or by creating and swapping? [duplic
...VecFast(vec<int> original) // no reference
{
vector<int> new_;
new_.swap(original);
}
That would work, but an easier way is
vector<int> new_(original);
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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 ...
Deleting multiple elements from a list
...
As a function:
def multi_delete(list_, *args):
indexes = sorted(list(args), reverse=True)
for index in indexes:
del list_[index]
return list_
Runs in n log(n) time, which should make it the fastest correct solution yet.
...
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_...
Should IBOutlets be strong or weak under ARC?
...efault and that the developer docs are being updated.
https://twitter.com/_danielhall/status/620716996326350848
https://twitter.com/_danielhall/status/620717252216623104
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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("^[^...