Question

I am trying to write a method that converts from engineering notation to double. The case I have now is very special! I mean I am not going to look for powers like “Mega, Giga and …” I am just looking for floating points.

Some valid examples of my Case are:

1.0 A should be 1

1.0064 mA or 1.0064 Ma should be 0.0010064 Note that I count both M and m as mili…that can be achived using ToLower() method. and that A or a counts as Ampere for current.

I have the same case for Voltage, so in that user can enter V or v instead.

again some valid cases:
256ma 366 m a 10.665 uA

So at the end before I pass this string to my converting method, I do text.ToLower().Remove(" ", string.Empty); this will hopefully leave me with a easy string to work on.

Now the second step is to split numbers from characters:
10.665ua should result in 10.665 and ua so then I can check for first character of ua against a list of allowed strings and find the power factor.

private List<string> AllowedCurrentStrings = new List<string>() { "a", "ma", "m", "ua", "u", "na", "n", "pa", "p" };

So I am looking for your help. first I need to know how to split numbers from characters and then group the characters into a string (Or do I need to do the later one?)

Or if you think my approach is not good, it would be nice to hear a better one from you!

Answer 1

You could try this:

    public double ConvertMeasure(string measure)
    {
        measure = measure.ToLower().Replace(" ", "");
        measure = measure.Substring(0, measure.Length - 1);
        char m = measure.Last();
        if (char.IsDigit(m))
            return double.Parse(measure, CultureInfo.InvariantCulture);

        double ret = double.Parse(measure.Substring(0, measure.Length - 1),
                                  CultureInfo.InvariantCulture);
        switch (m)
        {
            case 'm': return ret / 1E3;
            case 'u': return ret / 1E6;
            case 'n': return ret / 1E9;
            case 'p': return ret / 1E12;
        }
        return ret;
    }