An nvarchar column can store any Unicode data. A varchar column is restricted to an 8-bit codepage. Some people think that varchar should be used because it takes up less space. I believe this is not the correct answer. Codepage incompatabilities are a pain, and Unicode is the cure for codepage problems. With cheap disk … Read more
The Inversion of Control (IoC) and Dependency Injection (DI) patterns are all about removing dependencies from your code. For example, say your application has a text editor component and you want to provide spell checking. Your standard code would look something like this: What we’ve done here creates a dependency between the TextEditor and the … Read more
This is caused when there is a class file that your code depends on and it is present at compile time but not found at runtime. Look for differences in your build time and runtime classpaths.
On some (especially older) platforms (see the comments below) you might need to and then include the necessary header file: and the value of pi can be accessed via: In my math.h (2014) it is defined as: but check your math.h for more. An extract from the “old” math.h (in 2009): However: on newer platforms … Read more
%<>% isn’t exported by dplyr (only %>% is). You need to load magrittr instead. Your reproducible example is running into a subtle magrittr bug, which causes the evaluation of pipeline expressions to search for some operators in magrittr’s scope, rather than in the calling scope. That way, x %<>% y %>% z, which evaluates as … Read more
Here’s how you would use a for loop;
I have two local git repositories, both pointing to the same remote repository. In one git repository, if I do git format-patch 1, how can I apply that patch to the other repository?
This GitPro page does summarize the consequence of a git submodule update nicely When you run git submodule update, it checks out the specific version of the project, but not within a branch. This is called having a detached head — it means the HEAD file points directly to a commit, not to a symbolic … Read more
If you know what the Collatz conjecture is, I’m trying to make a calculator for that. I want to have x as my input so I don’t have to change x’s number and save every time I want to try out a new number. I get below error TypeError: not all arguments converted during string … Read more
As it is, both dimensions of your vector are 0. Instead, initialize the vector as this: This will give you a matrix of dimensions RR * CC with all elements set to 0.