Re: Calculation Error

Ah, that’s great, we can get a useful result without as big an impact as I thought it might be.

I suggest two actions:

1.  We try to come to one measure for horizontal space increase.

2.  We use Wayne’s calculations (or a summary of) in the understanding doc to show the justification.

Wayne, we’re looking to come up with a total increase from possible letter space, font-family substitution and word spacing.

So if letter spacing is 0.045em, and word spacing is 0.16em, that makes a roughly 15% increase in width on my test sentence:
https://alastairc.ac/tests/word-spacing.html (at the bottom).

If we used a letter-spacing only of 0.065em, that comes out at the same size horizontally. (Note tiny differences in letter-spacing make a big difference, word-spacing not so much.)

Would that letter-spacing value suffice?

Cheers,

-Alastair


From: Wayne Dick


Just in  case I made some more errors, here is my code.

http://nosetothepage.org/fontApps/src/HTML/

http://nosetothepage.org/fontApps/src/js/

The relevant files are:
For indivudula font family at a time
fontWidth.html
fontWidthX.js
famStatt.HTML
famStats.js
famWidth.js
GoogleFonts.js
Please check my work

Wayne


On Thu, Jun 8, 2017 at 3:46 PM, Wayne Dick <wayneedick@gmail.com<mailto:wayneedick@gmail.com>> wrote:
The empirical test I left off: I used my sample string unicode 32-126 and inserted  spaces every five characters. Then I set the letter spacing to 0.045 and word spacing to 0.16. Then I ran the test on Tahoma. I got that the average space taken by each character was 9.24px. Without the spaces  and with normal spacing I got an average of 8.6px. 9.20/8.6=1.074. Pretty close to the theoretical estimate.

On Thu, Jun 8, 2017 at 3:10 PM, Wayne Dick <wayneedick@gmail.com<mailto:wayneedick@gmail.com>> wrote:
When Alastair did his computations and got 150% enlargement that set off a red flag for me. I double checked Alastair's computations and he is right.
Letter spacing should change to 0.045em NOT 0.12em.

My mistake was in using the research percentages applied to whole letters, not the space between them as the researcher MacLiesh suggested. Thus, our letter spacing should be applied to the spacing between letters, not to letters. That is 0.12x0.25=.03em.  There was actually an improvement up to 0.24 of the space between letters. Then the improvement flattened. I did a linear interpolation from 0 to 0.24 when I got 0.12. I think in this case the research max 0.06em could make size problems for developers, but the min 0.03em is a little small from my personal experience, and the research plots in the MacLeish research. Thus, I recommend linear interpolation again to get 0.045em.
Word spacing is correct because it is applied to 1em, (a space character approximately). However when we compute the size increase due to word spacing we must divide by the average word size (language dependent (about 5 in English usage)).  So, to compute the effect of letter spacing on text length we should apply the following multiplication factor:
(1+letter-spacing)(1+(1/5)word-spacing)<= (1+0.045)(1+0.32)=1.07844<1.08.
Empirical Evidence: Let us look at an average font like Tahoma. The average character width is 8.69px including normal letter spacing.

Conclusion:
Word spacing should not change. Letter spacing should change from 0.12em to 0.045em.
Wayne