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Reshape three column data frame to matrix (“long” to “wide” format) [duplicate]
...hape2 and the tidyverse came plyr, with the daply function, as shown here: https://stackoverflow.com/a/7020101/210673
library(plyr)
daply(tmp, .(x, y), function(x) x$z)
## y
## x a b c
## x 1 2 3
## y 3 3 2
Using matrix indexing:
This is kinda old school but is a nice demonstration of m...
Overloading Macro on Number of Arguments
... ...
PS: __NARG__ is copied from Laurent Deniau & Roland Illig here: https://groups.google.com/group/comp.std.c/browse_thread/thread/77ee8c8f92e4a3fb/346fc464319b1ee5?pli=1
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Entity Framework rollback and remove bad migration
...SCRIPTION
This topic describes the Entity Framework Core commands. See https://docs.efproject.net for information on Entity Framework Core.
The following Entity Framework cmdlets are included.
Cmdlet Description
-------------------------- -------------...
What's is the difference between train, validation and test set, in neural networks?
... used to report the generalization error on the selected model. From here: https://www.coursera.org/learn/machine-learning/lecture/QGKbr/model-selection-and-train-validation-test-sets
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How do I sort an observable collection?
...exity of the interface involved and its relatively poor documentation (see https://stackoverflow.com/a/5883947/33080).
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How can I use optional parameters in a T-SQL stored procedure?
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Difference between core and processor
...g the complexity of a modern multi-processor, multi-core system.
Source:
https://software.intel.com/en-us/articles/intel-performance-counter-monitor-a-better-way-to-measure-cpu-utilization
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Hash and salt passwords in C#
...ctions like SHA256 weren't really intended for use with storing passwords:
https://patrickmn.com/security/storing-passwords-securely/#notpasswordhashes
Instead adaptive key derivation functions like PBKDF2, bcrypt or scrypt were. Here is a PBKDF2 based one that Microsoft wrote for PasswordHasher in...
C++ STL Vectors: Get iterator from index?
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Is there any way to close a StreamWriter without closing its BaseStream?
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