大约有 13,909 项符合查询结果（耗时：0.0363秒） [XML]
How do you do natural logs (e.g. “ln()”) with numpy in Python?
...
Correct, np.log(x) is the Natural Log (base e log) of x.
For other bases, remember this law of logs: log-b(x) = log-k(x) / log-k(b) where log-b is the log in some arbitrary base b, and log-k is the log in base k, e.g.
here k = e
l = np.l...
How do I view the SQL generated by the Entity Framework?
...
You can do the following:
IQueryable query = from x in appEntities
where x.id == 32
select x;
var sql = ((System.Data.Objects.ObjectQuery)query).ToTraceString();
or in EF6:
var sql = ((System.Data.Entity.Core.Objects.ObjectQuery)query)
...
How to use a custom comparison function in Python 3?
In Python 2.x , I could pass custom function to sorted and .sort functions
6 Answers
...
How are msys, msys2, and msysgit related to each other?
...know what to look for.) I do understand that MSYS is a minimal port of Linux tools to support development using MinGW, but I'm not clear on the relationship between the three of them or the teams that developed/maintain them.
...
Foreign key constraint may cause cycles or multiple cascade paths?
...ade paths and, rather than trying to work out whether any cycles actually exist, it assumes the worst and refuses to create the referential actions (CASCADE): you can and should still create the constraints without the referential actions. If you can't alter your design (or doing so would compromise...
Write to .txt file?
How can I write a little piece of text into a .txt file?
I've been Googling for over 3-4 hours, but can't find out how to do it.
...
convert a JavaScript string variable to decimal/money
...ent.getElementById(amtid4).innerHTML);
For formatting numbers, use toFixed:
var num = parseFloat(document.getElementById(amtid4).innerHTML).toFixed(2);
num is now a string with the number formatted with two decimal places.
...
An error occurred while installing pg (0.17.1), and Bundler cannot continue
...
Some kind of error resported here Installing PG gem on OS X - failure to build native extension
To install dependencies on Ubuntu try this:
sudo apt-get install libpq-dev
and this
gem install pg
share...
remove all variables except functions
...
Here's a one-liner that removes all objects except for functions:
rm(list = setdiff(ls(), lsf.str()))
It uses setdiff to find the subset of objects in the global environment (as returned by ls()) that don't have mode function (as returned by lsf.str())
...
Pad a string with leading zeros so it's 3 characters long in SQL Server 2008
...
@dwiener you got this behaviour because a char is a fixed length data type, so in your case char(6) means 6 chars long. If your actual value is less than 6 it is padded with blanks to the right so the proposed answer would produce incorect result for a char(6).
...