Code Comments

How to Find Interquartile Range in Java

In this post, I explained how to find quartiles in a list of numbers. As a slight add-on to that functionality, you can easily get the interquartile range. This basically means that you are finding the difference between the first and third quartiles. So I use the code to compute the quartiles and then use simple

How to Get Quartiles in Java

For a brief overview of what quartiles are, you might read the Wikipedia page on this topic. Basically, what it means is that if you were to break a list of numbers into four even parts, these would be the values that would separate them. But it gets a little complicated when your list doesn’t break

Java: Is an Integer an Odd Number?

This is a pretty simple tip, but I still thought I would share it for anyone who is interested. To find out whether an integer is odd, you can use the modulo operator. This operator tells you the remainder after dividing the number by some other number. If you divide any integer by 2, you

Research on Effectiveness of Software Development Practices

I came across an interesting summary of research that was performed at Microsoft regarding the effectiveness of commonly used software development practices, including test-driven development, code coverage, small teams, etc. It was interesting that the researchers tried to quantify how well these practices work, rather than rely on what supposed “experts” say. See the summary,

Troubleshooting Cygwin Error: “ssh command not found”

Cygwin is a software tool that allows you to run Linux programs in Windows. I have had good success in using it to run commands locally and to connect to other servers via ssh, scp, etc. I just got a new computer and installed the latest version of Cygwin, but when I tried to ssh

In Java, Use StringBuilder When Constructing Large Strings

This bit of advice is not new to me nor to the software development community. But recently I had one of those experiences where I put together a quick solution (to keep my code as simple as possible), and later I ran into a performance problem. And it was because I was violating this principle. I

Read Contents of Text File Into a Variable in a Bash Script

I’m learning something new about Linux every day, so this is something that will probably be obvious to many of you out there. But I needed today to read the contents of a file into a variable in a bash script. The simple way to go about doing this is to use the following command: myvar=`cat

How Training and Testing Works in Data Mining / Machine Learning

Imagine you wanted to come up with a “classifier” to predict whether Georgia would win a given American football game. So you might get (training) data from all their games from the previous two years. Then you might come up with rules based on that data. For example, if the quarterback throws for 300+ yards,

Save Text to a File in C

I had an occasion to learn a little about programming in C for the first time. One thing I needed to be able to do was save text to a file, but it was hard to find help for this on the Internet. This may be because it is called something slightly different in C

Execute a Command-line Script in Another Directory in Linux

I am running an application in one location on the file system, and I need to be able to invoke an application that is in a different directory on the file system. Due to personal preference, this other directory is not specified in the PATH variable. So I’m wondering how I can get Linux to