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How can I get a precise time, for example in milliseconds in Objective-C?
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Core Animation (QuartzCore.framework) also provides a convenience method, CACurrentMediaTime(), that converts mach_absolute_time() directly into a double.
– otto
Feb 27 '13 at 4:28
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Is there a difference between foo(void) and foo() in C++ or C?
Consider these two function definitions:
4 Answers
4
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Plotting two variables as lines using ggplot2 on the same graph
...t() from package reshape or reshape2) or gather()/pivot_longer() from the tidyr package:
library("reshape2")
library("ggplot2")
test_data_long <- melt(test_data, id="date") # convert to long format
ggplot(data=test_data_long,
aes(x=date, y=value, colour=variable)) +
geom_line()
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Vagrant reverse port forwarding?
...rKnownHostsFile=/dev/null -o StrictHostKeyChecking=no -o LogLevel=ERROR -o IdentitiesOnly=yes -i ~/.vagrant.d/insecure_private_key vagrant@127.0.0.1
SSH supports forwarding ports in the direction you want with the -R guestport:host:hostport option. So, if you wanted to connect to port 12345 on the ...
Differences between “BEGIN RSA PRIVATE KEY” and “BEGIN PRIVATE KEY”
...ally just the key object from PKCS#8, but without the version or algorithm identifier in front. BEGIN PRIVATE KEY is PKCS#8 and indicates that the key type is included in the key data itself. From the link:
The unencrypted PKCS#8 encoded data starts and ends with the tags:
-----BEGIN PRIVATE KE...
List all svn:externals recursively?
...s; fx, if we have external to folder and there is an external somewhere inside this folder - this won't show up b) the question is tagged tortoise svn, but answer is related to command line client
– pmod
Dec 8 '11 at 12:45
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JSON: why are forward slashes escaped?
... when embedding JSON in a <script> tag, which doesn't allow </ inside strings, like Seb points out.
Some of Microsoft's ASP.NET Ajax/JSON API's use this loophole to add extra information, e.g., a datetime will be sent as "\/Date(milliseconds)\/". (Yuck)
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difference and when to use getApplication(), getApplicationContext(), getBaseContext() and someClass
I'm new to android and I'm trying to understand the difference between getApplication() , getApplicationContext( ), getBaseContext() , getContext() and someClass.this and especially when to use the these methods in the following code lines:
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Enums and Constants. Which to use when?
.... There isn't a range of PI values, there is just PI.
Other points to consider are:
a: Constants don't necessarily indicate a relationship between the constants, whereas an enumeration indicates that something can be one of the set defined by the enum.
b: A defined enumeration can help you with t...
How to use shell commands in Makefile
...is supposed to be a make variable, these variables need to be assigned outside the recipe portion, e.g.:
FILES = $(shell ls)
all:
echo $(FILES)
Of course, that means that FILES will be set to "output from ls" before running any of the commands that create the .tgz files. (Though as Kaz n...