Friday, July 22, 2005

Channeling Grumperina

During the Pearland SnB on Tuesday, Monkee (aka giver of the Zephyr) asked me if I had enough yarn to finished my shawl. At the time, I thought I did. But after knitting for a few more days and watching the ball of yarn begin to shrink drastically with each row, I started getting nervous. Was I going to make it? And more importantly, how could I find out? Luckily for me, Grumperina has taken obsessive-compulsive knitting to a whole new level and I have learned from the best.

Step 1: Determine how much of the shawl is finished. I thought about doing this early on, but I didn't want to do it because I knew the numbers would make me unhappy. I knew that I would discover that I wasn't as far along as I thought I was. But I finally reached a point when I had to do the calculations. My first attempt was to do lots of mental math to try to derive a single elegant algebraic expression that calculated the percentage of shawl finished. Feel free to laugh out loud.

So, taking a cue from the Grumpster, off to the excel spreadsheet I went. Using my slowly decaying spreadsheet skills, I created at table that calculated the number of stitches in each row, the total number of stitches completed after each row, and the percentage of the shawl finished.
Excel Madness

Now, the spreadsheet calculations aren't perfect because some rows have double or triple yarn overs which are counted as one stitch instead of two or three. However, the "extra" stitches created by the double/triple yarn overs are decreased away on the following right side rows, so they didn't mess up the overall stitch count equation. But, I know my total stitch count is short. However, I'm not going to take the time to add in those extra stitches.

Result of step 1: I have 62.82% of the shawl finished. As predicted, the number made me very, very sad. I thought I was closer to 75% finished.

Step 2: Find weight of yarn not yet used. Easy to do (again following Grumperina's lead), just throw that baby on my digital food scale! Result: 1.125 oz
Not much there...

Step 3: Find weight of yarn knitted. Much more challenging because the shawl is still on a needle and has lots of stitch markers in place. Therefore, I need to weigh the entire shawl and subtract the weight of the needle and the stitch markers. But how do I weigh the needle alone when it is still in the shawl?

Hypothesis 1: The weight of a 40" US size 2 Addi Turbo is "close enough" to the weight of a 40" US size 3 Addi Turbo. (Size 3 being the needle in use.)

Corollary to Hypothesis 1: The weight of a 40" US size 1 Addi Turbo is "close enough" to the weight of a 40" US size 2 Addi Turbo.

If the corollary is true, then by a great leap of faith, the hypothesis is true.

Tests of the corollary prove the corollary to be false. (size 1 = 0.125 oz, size 2 = 0.25 oz)
Hummm....what to do? Obviously, I must propose a currently untestable Hypothesis 2 and pretend that it is true.

Hypothesis 2: The combined weight of a 40" US size 1 Addi Turbo and a US size 2 Addi Turbo is "close enough" to the weight of a 40" US size 3 Addi Turbo. (1 + 2 = 3, right?)

Now, weigh the shawl (2.625 oz)
Shawl still squashes nicely

Weigh an equivalent number of stitch makers and the size 1 and 2 needles (0.50 oz)
No witty caption

Result of step 3: 2.125 oz of yarn has been knitted.

Step 4: find percentage of yarn knitted. 2.125 / (2.125 + 1.125) = 65.38%

Step 5: Scream!

Step 6: Start planning bribes to get more yarn from Monkee.


Laura said...

Yes, I'm commenting on my own blog. I just wanted to say (before anyone else pointed it out) that I know that I'm using a ridiculous number of significant digits in my calculations especially considering how inexact my spreadsheet calculations are. But I don't care. :-)

Jennifer said...

Significant digits... Math... Calculations!!! I'm getting heart palpitations just reading your post. Must go lay down now... :)

monkeemaven said...

I bow to your mad number skillz! Do you want me to wind off a bit (knowing how accurate that is :\) or would you like the cone for a while?

(Was the Marmite & Vegemite some sort of precognitive bribe? ;) )

amylovie said...

EEekk! Way to scientific for my blood. I bow to your superior math skills.


carriescribe said...

Okay, does it totally give me away as a chemistry teacher if I tell you that the very first thought I had as I read was "that's an "optimistic" definition of significant?"

Your shawl looks lovely (well, not so much stuffed onto the scale, but much more so from your entry yesterday). Good luck with the bribing. :)

grumperina said...

I LOVE IT! This is exactly the kind of nonsense I would do. And then I'd think about it for a few hours and decide, yes, it would be worthwhile to post about it and throw the stuff back on the scale for photo opps :). As for needle weight, temporarily transfer all sts to size 2, weigh the size 3 and the markers, subtract from 2.625 oz. This may be worthwhile because I have a feeling the needle and markers make up a signifcant amt of the total project weight. Good luck!

Cordelia said...

Tee-hee. Love it. Especially the concern about significant digits.

Luck you, to have such a generous supplier!