大约有 40,000 项符合查询结果（耗时：0.0699秒） [XML]
How to work with complex numbers in C?
...h:
creal(z1): get the real part (for float crealf(z1), for long double creall(z1))
cimag(z1): get the imaginary part (for float cimagf(z1), for long double cimagl(z1))
Another important point to remember when working with complex numbers is that functions like cos(), exp() and sqrt() must be repl...
How to set -source 1.7 in Android Studio and Gradle
...
This is essentially the same as the accepted answer.
– Kerem
Aug 12 '15 at 12:20
1
...
Split comma-separated strings in a column into separate rows
...solution,
and two additional variants of Jaap's data.table methods.
Overall 8 different methods were benchmarked on 6 different sizes of data frames using the microbenchmark package (see code below).
The sample data given by the OP consists only of 20 rows. To create larger data frames, these 20...
Subscripts in plots in R
... How to load "2" from the variable? I have a loop and need to plot x_[1] x_[2] x_[3] ...
– 0x2207
Dec 11 '14 at 11:38
6
...
What do the terms “CPU bound” and “I/O bound” mean?
...U (doing calculations). A program that computes new digits of π will typically be CPU-bound, it's just crunching numbers.
A program is I/O bound if it would go faster if the I/O subsystem was faster. Which exact I/O system is meant can vary; I typically associate it with disk, but of course networ...
How do I measure the execution time of JavaScript code with callbacks?
... put this at the top of my app.
var start = process.hrtime();
var elapsed_time = function(note){
var precision = 3; // 3 decimal places
var elapsed = process.hrtime(start)[1] / 1000000; // divide by a million to get nano to milli
console.log(process.hrtime(start)[0] + " s, " + elapsed....
Saving interactive Matplotlib figures
...some fancy figure editor like Adobe Illustrator (or Inkscape).
EDIT post Fall 2012: As others pointed out below (though mentioning here as this is the accepted answer), Matplotlib since version 1.2 allowed you to pickle figures. As the release notes state, it is an experimental feature and does no...
Get list of all routes defined in the Flask app
... with the @app.route('/...') decorator. Is there a way to get a list of all the routes that have been declared throughout my app? Perhaps there is some method I can call on the app object?
...
What is the best collation to use for MySQL with PHP? [closed]
...site where you aren't 100% sure of what will be entered? I understand that all the encodings should be the same, such as MySQL, Apache, the HTML and anything inside PHP.
...
Read only file system on Android
...
Not all phones and versions of android have things mounted the same.
Limiting options when remounting would be best.
Simply remount as rw (Read/Write):
# mount -o rw,remount /system
Once you are done making changes, remount t...