Month: December 2015

Missing XMLData2.xml File

A number of readers have written to report that XMLData2.xml is missing from the downloadable source for Python for Data Science for Dummies. You encounter this file in Chapter 6, on page 108. The publisher has already added the file to the downloadable source, but you might be missing the file from your copy. If so, you can download it by clicking XMLData2.zip. I’m truly sorry about any problems that the missing file might have caused. Please be sure to let me know about your book specific question at [email protected].

 

The Internet – The Home of Old Data Made New

I have to admit to making this error myself.  I’ll perform a search online and fail to fully check the freshness date of the information I obtain. Of course, there are several levels of freshness date to consider. The first level is the information source. This is the easiest level of data to check. You simply look at the date of the material when you get to the page. Unfortunately, some authors don’t date their work, so you can’t always rely on a posting date. The next best alternative is to ask the search engine to list only those entries that come from a certain time frame. In most cases, you can verify that the information appearing in an article or other posting is current enough for your needs.

Unfortunately, just verifying the posting date may not be good enough. The second level of check is the version of the products discussed as part of the post. For example, you might come to my blog and find a post on CodeBlocks. Unless you read the article carefully, you might think that I’m discussing the latest version of CodeBlocks. However, I have a number of books that rely on CodeBlocks, so I might actually be discussing an older version of CodeBlocks that I used in a specific book. Reading carefully and ensuring you understand version issues is the best way to verify this second level of information.

A third level of freshness checking is the information sources used by the author. This is where things get tricky because the author could truly think that the information source used for an article is the most current available, yet it’s outdated before the author even uses it. Some technologies change so fast that using a resource even a few months old is deadly. These resources become outdated so quickly that they can blindside even a professional author, much less someone who writes on the side. Verifying this level of information requires that you depend on at least three information sources (I recommend finding as many as you can). Gently nudging an article author and mentioning that the information sources might contain outdated material is often helpful when done in a constructive manner.

Freshness checking can occur at even deeper levels. The point is that you can’t be sure that a resource that keeps information literally forever contains the latest information on any given topic. In addition, even when that information is available, it’s up to you to find it. I do try to provide the latest information available when I can. However, when the topic is a question on an older book, I need to address the question in the context of that book and will provide you with some sort of version information so you know what to expect. If you ever question the freshness of the information I provide, please feel free to contact me at [email protected].

 

Predicting Processed Rabbit Weight

One of the issues that faces someone who raises meat rabbits is how to predict the dressed or processed weight of the rabbit based on the live weight. After all, you can’t add more weight after the fact. First of all, you need to weigh the rabbit before you feed it, rather than after. Using the before feeding weight seems to provide more predictable results. I’ve found that rabbits can be picky eaters at times, so using this baseline ensures I’m not weighing different amounts of ingested food. Couple the before feeding weigh-in with a same time of day feeding time to ensure you get predictable results. (I also feed right before sundown because rabbits are nocturnal and will feed better at night.) However, there is always some variance, so you need to expect some range in the dressed weight of the rabbit.

Younger rabbits tend to dress out at a higher percentage of their live weight. Most people wait at least eight weeks before attempting to process rabbits. However, these younger rabbits are also considerably smaller than a more mature rabbit. Waiting until thirteen to fifteen weeks often produces a nicer rabbit even if the live weight to processed weight ratio is smaller.

What you feed the rabbit will also make a difference in the ratio because some types of food tend to produce more fat, than lean meat. Adding corn or other grains to the feed will cause the rabbit to be more tender and grow faster, but at a lower ratio and with more inner fat (the fat that isn’t removed with the skin). When you feed anything other than alfalfa pellets, you change the texture of the rabbit and its fat content, and therefore the ratio of live weight to processed weight. For example, feeding the rabbit grass will tend to make it leaner.

The kind of rabbit can also make a big difference. A New Zealand rabbit may only provide a ratio of 55% live weight to processed weight, while a Dutch can provide a ratio as high as 60%. Mixed breed rabbits increase the uncertainty of yield, but do provide advantages in genetic diversity, which can improve the taste of the meat and reduce the need to use medications that pure bred rabbits could require. In short, you need to consider the trade-offs of various decisions you make during the entire process.

In general, you can expect a ratio as low as 50% for a mixed breed rabbit and somewhere around 65% for a Californian/New Zealand mix. However, you must take all sorts of other factors into consideration as previously mentioned. To help me calculate the processed weight better, I started to keep records of live weight to processed weight ratios, ensure I fed the rabbits the same diet, and kept my stock as close as possible to the same mix. Even so, I find that each processing session provides slightly different ratios. Let me know about your live weight to processed weight insights at [email protected].