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Count number of rows within each group
..., there is no need to rename each variable in by= like list(year=df1$year) etc. A data.frame is a list already so aggregate(df1[c("Count")], by=df1[c("Year", "Month")], FUN=sum, na.rm=TRUE) will work.
– thelatemail
Jul 17 '19 at 22:27
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C99 stdint.h header and MS Visual Studio
...thout this header I have no definitions for useful types such as uint32_t, etc.
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Why cannot cast Integer to String in java?
....toString(myInt, radix) that lets you specify whether you want hex, octal, etc. If you want to be consistent in your code (purely aesthetically, I guess) the second form can be used in more places.
Edit 2 I assumed you meant that your integer was an int and not an Integer. If it's already an Intege...
POST data with request module on Node.JS
...sing form will make the arrays into field[0].attribute, field[1].attribute etc. Instead use body like so.
var jsonDataObj = {'mes': 'hey dude', 'yo': ['im here', 'and here']};
request.post({
url: 'https://api.site.com',
body: jsonDataObj,
json: true
}, function(error, response, body...
Convert timestamp to readable date/time PHP
...are using PHP date(), you can use this code to get the date, time, second, etc.
$time = time(); // you have 1299446702 in time
$year = $time/31556926 % 12; // to get year
$week = $time / 604800 % 52; // to get weeks
$hour = $time / 3600 % 24; // to get hours
$minute = $time / 60 ...
How to get just the parent directory name of a specific file
...ame FilenameUtils class to grab the name from the result, use lastIndexOf, etc.
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CSS background-image - What is the correct usage?
...e from your css file it can be
{background-image: url(your image.png/jpg etc);}
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CodeIgniter - accessing $config variable in view
...our controller should collect all the information from databases, configs, etc. There are many good reasons to stick to this. One good reason is that this will allow you to change the source of that information quite easily and not have to make any changes to your views.
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What does PermGen actually stand for?
...know what PermGen is, what it's used for, why it fails, how to increase it etc.
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Visual Studio Expand/Collapse keyboard shortcuts [duplicate]
...M or CTRL + M + O to collapse all code blocks, regions, namespaces, etc.
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