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Select first 4 rows of a data.frame in R
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Use head:
dnow <- data.frame(x=rnorm(100), y=runif(100))
head(dnow,4) ## default is 6
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Using jQuery how to get click coordinates on the target element
...api.jquery.com/position/
HTML
<body>
<div id="A" style="left:100px;"> Default <br /> mouse<br/>position </div>
<div id="B" style="left:300px;"> offset() <br /> mouse<br/>position </div>
<div id="C" style="left:500px;"> posit...
Getting key with maximum value in dictionary?
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You can use operator.itemgetter for that:
import operator
stats = {'a':1000, 'b':3000, 'c': 100}
max(stats.iteritems(), key=operator.itemgetter(1))[0]
And instead of building a new list in memory use stats.iteritems(). The key parameter to the max() function is a function that computes a key t...
Python time measure function
...()
print '%s function took %0.3f ms' % (f.func_name, (time2-time1)*1000.0)
return ret
return wrap
And the usage is very simple, just use the @timing decorator:
@timing
def do_work():
#code
Python 3:
def timing(f):
def wrap(*args, **kwargs):
time1 = time.time()
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pyplot axes labels for subplots
...import matplotlib.pyplot as plt
x = range(1, 101)
y1 = [random.randint(1, 100) for _ in xrange(len(x))]
y2 = [random.randint(1, 100) for _ in xrange(len(x))]
fig = plt.figure()
ax = fig.add_subplot(111) # The big subplot
ax1 = fig.add_subplot(211)
ax2 = fig.add_subplot(212)
# Turn off axis lin...
How do I keep CSS floats in one line?
...iv> that uses this cross-browser min-width hack:
.minwidth { min-width:100px; width: auto !important; width: 100px; }
You may also need to set "overflow" but probably not.
This works because:
The !important declaration, combined with min-width cause everything to stay on the same line in IE...
Reset C int array to zero : the fastest way?
Assuming that we have a T myarray[100] with T = int, unsigned int, long long int or unsigned long long int, what is the fastest way to reset all its content to zero (not only for initialization but to reset the content several times in my program)? Maybe with memset?
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How can I truncate a double to only two decimal places in Java?
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If you need it for calculations, use java.lang.Math:
Math.floor(value * 100) / 100;
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Approximate cost to access various caches and main memory?
...5 cycles ( 40.2 - 22.5 ns )
remote L3 CACHE (Ref: Fig.1 [Pg. 5]) ~100-300 cycles ( 160.7 - 30.0 ns )
local DRAM ~60 ns
remote DRAM ~100 ns
EDIT2:
The most important is the notice under the...
How to draw a circle with text in the middle?
...is is your best bet:
http://cssdeck.com/labs/aplvrmue
.badge {
height: 100px;
width: 100px;
display: table-cell;
text-align: center;
vertical-align: middle;
border-radius: 50%; /* may require vendor prefixes */
background: yellow;
}
.badge {
height: 100px;
width: 100px;
...