Thursday, April 29, 2010

Microsoft Office Lullaby

[This was originally posted at http://timstall.dotnetdevelopersjournal.com/microsoft_office_lullaby.htm]

Somehow, after having three kids, I started singing this kind of lullaby (sung to the classic theme "Hush little baby"):

Hush little baby, don't say a word, Daddy's going to teach you Microsoft Word.

And if that MS Word does not spell, then Daddy's going to teach you Microsoft Excel

And if that Excel doesn't save the day, then Daddy's going to teach you VBA

And if VBA doesn't hit the mark, then Daddy's going to teach you how to program C#.

Wednesday, April 28, 2010

Chicago Code Camp this Saturday

[This was originally posted at http://timstall.dotnetdevelopersjournal.com/chicago_code_camp_this_saturday.htm]

This Saturday is the 2010 Chicago Code Camp (Last year's rocked!) For those who have a passion for coding, this is the event for you!

 

Wednesday, April 21, 2010

Technology is the engine, but the Business is the steering wheel

[This was originally posted at http://timstall.dotnetdevelopersjournal.com/technology_is_the_engine_but_the_business_is_the_steering_w.htm]

I like analogies. Initially, I was thinking of polar coordinates, where technology is the magnitude, but the Business is the direction - however that sounded too techy.

The idea is that you can have the most powerful technology in the world, but if it's not focused in a profitable direction, your business (which pays for the technology) will never get to the right place.

You need both tech and business, else you plateau very quickly. Without business understanding, the technologists can build amazing things - that no one wants. That's fine for hobbyists and CS college students, but not sustainable for companies.

Without technical understanding, the business people can dream of profitable ideas - that no one can build.

Monday, April 19, 2010

Unit testing random methods

[This was originally posted at http://timstall.dotnetdevelopersjournal.com/unit_testing_random_methods.htm]

You can unit test random methods by running the method in a loop and checking for statistical results.

For example, say you have a method to return a random integer between 1 and 10 (this could just as easily be to return any type between any range). You could run the test 100,000 times and confirm that the statistical distribution makes sense. With a sufficient sample size, there should be at least one of each value. The mathematically advanced could apply better statistics, like checking the proper distribution.

Here's a simple sample. It runs the random method in a loop, and checks just that each value was returned at least once.

public class MathHelper
{
    private static Random _r = new Random();

    public static int GetRandomInt()
    {
        //return Random int between 1 and 10
        //recall that upper bound is exclusive, so we use 11
        return _r.Next(1, 11);
    }
}

[TestMethod]
public void Random_1()
{
    int iMinRandomValue = 1;
    int iMaxRandomValue = 10;

    //Initialize results array
    //ignore 0 value
    int[] aint = new int[11];
    for (int i = iMinRandomValue; i <= iMaxRandomValue; i++)
    {
        aint[i] = 0;
    }

    //Run method many times, record result
    //Every time a number is returned, increment its counter
    const int iMaxLoops = 1000;
    for (int i = 0; i < iMaxLoops; i++)
    {
        int n = MathHelper.GetRandomInt();
        aint[n] = aint[n] + 1;
    }

    //assert that each value, 1-10, was returned
    for (int i = iMinRandomValue; i <= iMaxRandomValue; i++)
    {
        Assert.IsTrue(aint[i] > 0,
            string.Format("Value {0} never returned.", i));
    }

}

Of course, this assumes you're explicitly trying to test the random method - you could mock it out if the method is just a dependency and you're trying to test something else.