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To find whether a column exists in data frame or not
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202
Assuming that the name of your data frame is dat and that your column name to check is "d", you...
mongodb count num of distinct values per field/key
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XAMPP, Apache - Error: Apache shutdown unexpectedly
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How to show popup message like in Stack Overflow
... {
font-family:Arial,Helvetica,sans-serif;
position:fixed;
top:0px;
left:0px;
width:100%;
z-index:105;
text-align:center;
font-weight:bold;
font-size:100%;
color:white;
padding:10px 0px 10px 0px;
background-color:#8E1609;
}
#message span {
text-al...
How to deserialize a list using GSON or another JSON library in Java?
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edited Jul 15 '16 at 20:56
answered Nov 30 '10 at 21:14
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Getting and removing the first character of a string
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170
See ?substring.
x <- 'hello stackoverflow'
substring(x, 1, 1)
## [1] "h"
substring(x, 2)
## ...
Can you list the keyword arguments a function receives?
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edited Oct 13 '08 at 9:12
answered Oct 13 '08 at 9:02
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Resharper- Find all unused classes
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edited Oct 14 '14 at 2:07
answered Jan 10 '11 at 11:22
u...
Android: How to enable/disable option menu item on button click?
...example_foobar).setEnabled(false);
}
return true;
}
On Android 3.0 and higher, the options menu is considered to always be open when menu items are presented in the action bar. When an event occurs and you want to perform a menu update, you must call invalidateOptionsMenu() to request that...
Override compile flags for single files
...add_compile_options
add_compile_options(-Wall -Weffc++ -pedantic -std=c++0x)
or for CMake versions < 3.0 to do something more like:
set(CMAKE_CXX_FLAGS "${CMAKE_CXX_FLAGS} -Wall -Weffc++ -pedantic -std=c++0x")
In response to further questions in the comments below, I believe it's impossi...