{"id":3754,"date":"2012-07-27T07:34:35","date_gmt":"2012-07-27T12:34:35","guid":{"rendered":"https:\/\/blogs.mathworks.com\/pick\/?p=3754"},"modified":"2012-07-27T07:35:39","modified_gmt":"2012-07-27T12:35:39","slug":"1000-unit-converters-at-your-fingertips","status":"publish","type":"post","link":"https:\/\/blogs.mathworks.com\/pick\/2012\/07\/27\/1000-unit-converters-at-your-fingertips\/","title":{"rendered":"1000 unit converters at your fingertips!"},"content":{"rendered":"
\r\n

Jiro<\/a>'s pick this week is Unit Converters<\/a> by Chad Greene<\/a>.\r\n <\/p>\r\n

This week's pick comes from Sam G's recommendation<\/a>. I really like what he has to say about it:\r\n <\/p>\r\n

I like functions that I can use without asking myself, \"now how do I use this function again? What are the inputs and outputs?\r\n What is the name of the function?\" The NaN suite and unit conversion functions both meet this criteria.<\/i><\/p>\r\n

He makes a great point. I always make sure (and encourage others) to comment the code and create very meaningful help. But\r\n having a well thought-out function name and calling syntax can make a world of difference. I also make sure that the variable\r\n name used for the input arguments are well-named. This ensures that the function hints<\/a> display a meaningful text.\r\n <\/p>\r\n

So what do Chad's functions do? In a nutshell, they are a collection of over a 1000 functions for converting units of various\r\n quantities, including acceleration, angle, area, computing, force, frequency, energy, length, mass, power, pressure, speed,\r\n temperature, time, and volume. His functions follow a consistent naming convention of \"from2to\". For example, 3 miles in kilometers\r\n is,\r\n <\/p>

mi2km(3)<\/pre>
ans =\r\n    4.8280\r\n<\/pre>
In the feedback section<\/a> of the entry, I noticed a few dialogs about whether the functions should be organized in separate folders. I've chimed in\r\n      suggesting the use of packages<\/a>. Ultimately, it also has to do with preference, and Chad makes a good point that his functions are very easy to remember\r\n      and use, so simply putting everything in one folder and adding it to the path is sufficient.\r\n   <\/p>\r\n   
But since I brought it up, let me explain a little bit about the benefits of packages in this case. Packages allow you to\r\n      put functions together in their own namespace. In Chad's case, you can put the 1000+ functions into a folder, and name the\r\n      folder starting with a \"+\". For example, I put them in a folder named \"+convert\". Then, as long as the folder containing \"+convert\"\r\n      is in the MATLAB path, you can call them like this:\r\n   <\/p>
convert.mi2km(3)<\/pre>
By using packages, your functions need only be uniquely named within the package. You won't have to worry about other functions\r\n      developed by others clashing with your function names.\r\n   <\/p>\r\n   
Another benefit of packages is the ease of discoverability of the functions. Some of you may have used tab-completion<\/a> to find functions you're looking for. By putting functions in packages, you can narrow the scope of the search to just the\r\n      package. If I type \" convert.m2<\/tt> \" and the Tab key, it will show only the functions that start with \" m2<\/tt> \" in my \"convert\" package.\r\n   <\/p>\r\n   
Typically, if I'm creating individual functions that aren't related to each other, I don't bother placing them in packages.\r\n      But when I have lots of related functions, that's when I may use packages.\r\n   <\/p>\r\n   
Comments<\/b><\/p>\r\n   
Thanks Chad for giving us over a thousand useful conversion functions at our fingertips. And thanks Sam G for the recommendation!<\/p>\r\n   
Let us know what you think here<\/a> or leave a comment<\/a> for Chad.\r\n   <\/p>\r\n   
By the way, a few months ago Brett<\/a> wrote a Pick of the Week post<\/a> on another unit conversion tool<\/a> . It's a very powerful class with utilities for automatic conversion and error checking. I highly recommend checking it out\r\n      as well.\r\n   <\/p>