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R: += (plus equals) and ++ (plus plus) equivalent from c++/c#/java, etc.?
...= question. In other languages += can be applied to immutable types (like strings in .net). The operation simply creates a new object and assigns the given variable to that new object. Immutability is maintained and the variable is updated.
– SFun28
Apr 21 '...
The specified type member 'Date' is not supported in LINQ to Entities Exception
... are implemented by converting to SQL where the datetime is converted to a string and that is truncated. This makes the query run significantly slower, in proportion to the number of records processed.
– urig
Mar 21 '17 at 13:08
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Cluster analysis in R: determine the optimal number of clusters
...uld be indicated by this method:
Two. You can do partitioning around medoids to estimate the number of clusters using the pamk function in the fpc package.
library(fpc)
pamk.best <- pamk(d)
cat("number of clusters estimated by optimum average silhouette width:", pamk.best$nc, "\n")
plot(pam(d...
What are the benefits of Java's types erasure?
...) ends up with [7,8]
I know from the type that it doesn't do one thing for String and one thing for Int.
Furthermore, I know that the List.add function can not invent values of T out of thin air. I know that if my asList("3") has a "7" added to it, the only possible answers would be constructed out...
How can I pop-up a print dialog box using Javascript?
...message box in asp net core for instance:
await JSRuntime.InvokeAsync<string>("alert", "Hello user, this is the message box");
To have a confirm message box:
bool question = await JSRuntime.InvokeAsync<bool>("confirm", "Are you sure you want to do this?");
if(question == true)
...
Cannot simply use PostgreSQL table name (“relation does not exist”)
...
Put the dbname parameter in your connection string. It works for me while everything else failed.
Also when doing the select, specify the your_schema.your_table like this:
select * from my_schema.your_table
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How to specify more spaces for the delimiter using cut?
...e spaces with the cut command? (like " "+) ?
For example: In the following string, I like to reach value '3744', what field delimiter I should say?
...
How to create the branch from specific commit in different branch
...ev. Branching out from a commit of master (older than the merge) won't provide you with the changes of dev.
If you want to permanently integrate new changes from master into your feature branches, you should merge master into them and go on. This will create merge commits in your feature branches...
Perform debounce in React.js
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2018: try promise debouncing
We often want to debounce API calls to avoid flooding the backend with useless requests.
In 2018, working with callbacks (Lodash/Underscore) feels bad and error-prone to me. It's easy to encounter boilerplate and concurrency issues due to API calls resolving in an a...
iPhone UITextField - Change placeholder text color
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Since the introduction of attributed strings in UIViews in iOS 6, it's possible to assign a color to the placeholder text like this:
if ([textField respondsToSelector:@selector(setAttributedPlaceholder:)]) {
UIColor *color = [UIColor blackColor];
textField....