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Summarizing multiple columns with dplyr? [duplicate]
...le(1:5, 10, replace=T),
grp = sample(1:3, 10, replace=T))
# Convert to tidy format using gather
df %>%
gather(key = variable, value = value, a:d) %>%
group_by(grp, variable) %>%
summarize(mean = mean(value)) %>%
spread(variable, mean)
#> Source: local da...
How to measure time in milliseconds using ANSI C?
...y, so if you have a ticks value and the frequency is known, you can easily convert ticks to elapsed time. It is actually not guaranteed that a monotonic clock reflects the current system time in any way, it may also count ticks since a system startup. But it guarantees that a clock is always run up ...
What is the JavaScript equivalent of var_dump or print_r in PHP? [duplicate]
...o know the original data type of member, since JS
//always converts it to a string and no other way to parse objects.
sContents += repeatString(' ', recursionLevel) + " " + member +
": " + dump(v[member], "none", recursionLevel + 1) + "\n";
...
PowerShell script to return versions of .NET Framework on a machine?
... slightly again, so there's now a nice MSDN article here explaining how to convert the Release value to a .Net version number, it's a total train wreck :-(
This looks right to me (note that it outputs separate version numbers for WCF & WPF on 3.0. I don't know what that's about). It also output...
When restoring a backup, how do I disconnect all active connections?
... multiuser
mode. If error occurs please execute following command it will convert
database in multi user.*/
ALTER DATABASE YourDB SET MULTI_USER
GO
Reference : Pinal Dave (http://blog.SQLAuthority.com)
Official reference: https://msdn.microsoft.com/en-us/library/ms345598.aspx
...
Is Fortran easier to optimize than C for heavy calculations?
...t heavily use c++ for their high performance modeling. Additionally Sandia converted one of their modeling software (LAMMPS) over from fortran to c++ adding in a number of awesome enhancements.
– Zachary Kraus
Sep 9 '15 at 3:46
...
What's invokedynamic and how do I use it?
...ions on the types of values supplied to its operations (e.g. Java)
Weak - converts (casts) arguments of an operation if those arguments have incompatible types (e.g. Visual Basic)
Knowing that Java is a Statically and Weakly typed, how do you implement Dynamically and Strongly typed languages on t...
Why doesn't the example compile, aka how does (co-, contra-, and in-) variance work?
...?
slot.get will then throw an error at runtime as it was unsuccessful in converting an Animal to Dog (duh!).
In general mutability doesn't go well with co-variance and contra-variance. That is the reason why all Java collections are invariant.
...
insert multiple rows via a php array into mysql
...duct of a 1400 by 1400 set of int values many of which are zero. I need to convert that to a many to many relationship using an intermediary table to save space hence the need for inserts as opposed to a bulk insert
– toofarsideways
Apr 23 '09 at 2:26
...
This Handler class should be static or leaks might occur: IncomingHandler
...the whole point. Unless he has some ultra cool compiler that automatically converts inner classes to static classes when they don't use class variables.
– Sogger
Jan 7 '15 at 18:22
...