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STL or Qt containers?
... (see the std::string COW controversy). Some STL implementations are especially
bad.
provide hashes, which are not available unless you use TR1
The QTL has a different philosophy from the STL, which is well summarized by J. Blanchette: "Whereas STL's containers are optimized for raw speed, Qt's co...
NoSQL (MongoDB) vs Lucene (or Solr) as your database
...arned:
You can easily use Lucene/Solr in lieu of MongoDB for pretty much all situations, but not vice versa. Grant Ingersoll's post sums it up here.
MongoDB etc. seem to serve a purpose where there is no requirement of searching and/or faceting. It appears to be a simpler and arguably easier trans...
See :hover state in Chrome Developer Tools
...t not if you make changes onhover using JS.
– matthew_360
Feb 6 '15 at 16:31
Here's a quick video I threw together dem...
Changing the maximum length of a varchar column?
...
You need
ALTER TABLE YourTable ALTER COLUMN YourColumn <<new_datatype>> [NULL | NOT NULL]
But remember to specify NOT NULL explicitly if desired.
ALTER TABLE YourTable ALTER COLUMN YourColumn VARCHAR (500) NOT NULL;
If you leave it unspecified as below...
ALTER TABLE Your...
Should I write script in the body or the head of the html? [duplicate]
...
I would answer this with multiple options actually, the some of which actually render in the body.
Place library script such as the jQuery library in the head section.
Place normal script in the head unless it becomes a performance/page load issue.
Place script associa...
Get the date (a day before current time) in Bash
... a one-liner, so cut and paste should work -- no line endings assumed. date_days_past () { days_past=${1:-0}; if ! date -v-${days_past}d +%Y%m%d 2>/dev/null; then date --date="-${days_past} day" +%Y%m%d; fi }
– Noah Spurrier
May 16 '16 at 21:29
...
Histogram Matplotlib
... compute the widths using np.diff, pass the widths to ax.bar and use ax.set_xticks to label the bin edges:
import matplotlib.pyplot as plt
import numpy as np
mu, sigma = 100, 15
x = mu + sigma * np.random.randn(10000)
bins = [0, 40, 60, 75, 90, 110, 125, 140, 160, 200]
hist, bins = np.histogram(x,...
Difference between static and shared libraries?
...
Shared libraries are .so (or in Windows .dll, or in OS X .dylib) files. All the code relating to the library is in this file, and it is referenced by programs using it at run-time. A program using a shared library only makes reference to the code that it uses in the shared library.
Static librar...
How do I call a dynamically-named method in Javascript?
I am working on dynamically creating some JavaScript that will be inserted into a web page as it's being constructed.
9 An...
SQL update query using joins
...
I usually start with semicolon to terminate previous statement (if any). CTE rocks ! Simple to design complicated query / joined updates. I use it all the time...
– Adam W
Dec 17 '15 at 5:19
...