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How to set size for local image using knitr for markdown?
... using this function is that it is portable in the sense that it works for all document formats that knitr supports, so you do not need to think if you have to use, for example, LaTeX or Markdown syntax, to embed an external image. Chunk options related to graphics output that work for normal R plot...
Convert char to int in C and C++
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Well, in ASCII code, the numbers (digits) start from 48. All you need to do is:
int x = (int)character - 48;
Or, since the character '0' has the ASCII code of 48, you can just write:
int x = character - '0'; // The (int) cast is not necessary.
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How to change background color in android app
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Ravi VyasRavi Vyas
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How do I know which version of Javascript I'm using?
...eaten-path one is IE9 - it implements ECMAScript 5, but doesn't implement all the features of JavaScript 1.8.5 (not sure what they're calling this version of JScript, engine codenamed Chakra, yet).
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Why does Oracle 9i treat an empty string as NULL?
...r exists but is not known by the user, data where there is no answer, etc. all of which constitute some sense of NULL).
By the time that the SQL standard came around and agreed that NULL and the empty string were distinct entities, there were already Oracle users that had code that assumed the two ...
Why is it Valid to Concatenate Null Strings but not to Call “null.ToString()”?
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11 Answers
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How can I start an interactive console for Perl?
...ms to provide the best almost-out-of-the-box solution (you may have to install rlwrap). All third-party REPL/console solutions, including perlconsole, are cumbersome to install and often have more limitations.
– mklement0
Jul 8 '15 at 3:09
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How to get the difference between two arrays in JavaScript?
... The fastest way is the most obviously naive solution. I tested all of the proposed solutions for symmetric diff in this thread, and the winner is: function diff2(a, b) { var i, la = a.length, lb = b.length, res = []; if (!la) return b; else if (!lb) r...
What's the use/meaning of the @ character in variable names in C#?
...terfacing with other
programming languages. The character @
is not actually part of the
identifier, so the identifier might be
seen in other languages as a normal
identifier, without the prefix. An
identifier with an @ prefix is called
a verbatim identifier.
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jquery disable form submit on enter
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Usually form is submitted on Enter when you have focus on input elements.
We can disable Enter key (code 13) on input elements within a form:
$('form input').on('keypress', function(e) {
return e.which !== 13;
});
DEMO: ...