22 May 2013

The Ruby Reflector

Topic

Comma-Separated Values

  Source Favicon

Kalzumeus Podcast 4: Apps That Matter, Angel Investing, and B2B Sales with Matt Wensing of Stormpulse

By Patrick of Kalzumeus Software 1 month ago.
Email

…data which is available in the public domain, and transform it from GBs of opaque CSV files into predictions like "The factory which makes the widget that you're running low on has a high probability of closure three days from now as a result of this hurricane", which lets the user take consequential actions like "Put in a rush order at our alternate supplier so our main production line doesn't block on lack of input 6 days from now." When factory lines go down …

kalzumeus.com Read
  Source Favicon

Visualising classifier results with R and ggplot2

By Paul Ingles of pingles 2 months ago.
Email
binary classification plot

Our results were captured in a CSV file and looked a little like this:

A,0.25,0.15 A,0.2,0.19 B,0.19,0.25

Each line contains the item's actual class, the predicted probability for membership of class A, and the predicted probability for membership of class B. Using ggplot2 we produce the following:

Items have been classified into 2 groups- A and B. The axis show the log probability (we're using Naive Bayes to classify items) that the item belongs to the specified class. We …

oobaloo.co.uk Read
  Source Favicon

Evaluating classifier results with R part 2

By Paul Ingles of pingles 2 months ago.
Email

…of test data and capture both the actual class and the predicted class. Our results are stored in a CSV file and will look a little like this:

actual, predicted A, B B, B, C, C B, A

Analysing with Caret

With our results data as above we can run the following to produce a confusion matrix with caret:

results.matrix now contains a confusionMatrix full of information. Let's take a look at some of what it shows. The first table shows the contents of our matrix:

Reference Prediction …

oobaloo.co.uk Read
  Source Favicon

Selling Info Products: Discounts Help, But Not A Ton

By Giles Bowkett of Giles Bowkett 3 months ago.
Email

I downloaded a CSV from PayPal, which I use (despite obvious misgivings) for the majority of my info product business. I then filtered it only for sales of my book, and did a little math. The code's in a gist . The numbers look like this:

discount regular total copies sold 71 368 439 income 1,569.95 13,176.51 14,746.46

This means the discounted copies made up about 16% of the total copies sold and 10.6% of the total income from the product. I did this a couple days ago, …

gilesbowkett.blogspot.com Read
  Source Favicon

Bingo Card Creator (and other stuff) Year in Review 2012

By Patrick of Kalzumeus Software 5 months ago.
Email

I'm Patrick McKenzie (occasionally better known as patio11). When I started my business six years ago, I was greatly inspired by a few other folks who published the minutiae of their software businesses, particularly actual sales and expenses numbers. I resolved to do it for Bingo Card Creator, my (first) software business, and then just kept up the habit. I traditionally post the year's numbers and my reflections on what worked and what didn't right before Christmas: see years …

kalzumeus.com Read
  Source Favicon

Auditing login attempts in MySQL

By Miguel Angel Nieto of MySQL Performance Blog 5 months ago.
Email

…be lost. So if you really need that information you should copy it to another table or export to a csv for further analysis.

Conclusion

We don't have too many audit capabilities in MySQL Community so logging all events and then filter them with custom-made scripts is the best solution we have nowadays. If you are using Percona Server you can get more detailed information about what a particular user is doing. All options can be combined to meet your needs.

The post Auditing …

mysqlperformanceblog.com Read
  Source Favicon

MySQL Minutiae: Table Engines

By Davey Shafik of Engine Yard Developer Blog 5 months ago.
Email

You can easily flip this and INSERT INTO ... SELECT from the CSV table to pull in existing CSV data.

CSV is great for maintaining portability and interoperability, since it is essentially just a CSV file.

MERGE

The MERGE table engine allows you to create a table that represents a UNION between two or more identical MyISAM tables.

MERGE can allow you to split large datasets across multiple disks, this can be help in alleviating performance issues when doing schema updates (e.g. …

engineyard.com Read
  Source Favicon

12 Gems of Christmas #3 - thor

By Mike Perham of Mike Perham 5 months ago.
Email

…its wiki for many common use cases. Consider a simple example, create a task to process a CSV file:

# inventory.thor class Inventory < Thor include Thor::Actions desc "process_csv FILE" , "process the nightly inventory update" method_option :delete , :aliases => "-d" , :desc => "Delete the file after parsing it" def process_csv ( file ) # do something, maybe like: # require 'inventory_file' #InventoryFile.new(file).process! …

mikeperham.com Read
  Source Favicon

#396 Importing CSV and Excel

On RailsCasts 5 months ago.
Email

Allow users to import records into the database by uploading a CSV or Excel document. Here I show how to use Roo to parse these files and present a solution for validations.

railscasts.com Read
  Source Favicon

Rounded Corners 351 — Data Kalashnikov

By Assaf of Labnotes 8 months ago.
Email

…the testing culture in Github projects , for example:

Because contribution has become so easy, project owners reported seeing what they called drive-by commits.

§ PIN number analysis : and the winner is ... 1234!

§ Friedrich Lindenberg :

CSV is the data Kalashnikov: not pretty, but many wars have been fought with it and kids can use it. # okfest

blog.labnotes.org Read