Clever Maths people - I need your help!
 

This site:

http://46.101.125.20:8080

If you click on WIZARD it describes a Function / Equation that you need to enter to create a nomogram.

I'm trying to put together a PDF of a High resolution manoeuvring board in metric, and I need a nomograph for Minutes (0-200) to Metres / Kilometres (0 - 200?) then to Knots.

I'm fine with circles and triangles but equations like this and trying to create one that fits the requirement, I have no idea how to do that.

Can anyone please help?

Thanks

Seems like template #2 is the most similar to your Speed=Distance/Time. Where the third variable would need to be defined as function 1/z. But I let it generate with default settings (just to see it works) for 7 minutes now and nothing comes out. So I suspect it (or the back end) is buggy.

That's sad, as you found a nice gem in the interwebs with this one.

Yeah, 20 minutes later still nothing. Loosing the little bit of faith I had left in it just being slow. And I'm usually patient enough. Did you get any result?

There is a Windows installation procedure to let it run on your PC:
http://pynomo.org/wiki/index.php/Installation

I don't have the time to try it now. Maybe one day later I will try it. Supposedly you should be able to copy the script from the website to a text file and save it with .py extension.

Caveat: I'm no math wiz.


One Yard is 0.9144 meters - so you can pretty much use the yard scale on the existing MB as an estimation of meters (or kilometers) traveled in a given time period.


But, I did manage to modify the nomogram to make it slightly more accurate when using meters/kilometers.


Try it out and let me know what you think:


https://i.imgur.com/EYybfX9.png

Looks great. I guess you just streched the range scale to 1.09361 times the length of the original scale?

Thank you.



Actually, I tried scaling it based on the proportions - but that didn't seem to work so well. What I ended up doing was compressing*/repositioning it until various pre-calculated results [mostly] matched up.


I must admit, though, that I'm not entirely sure that I got it just right. That's why I'd be very interested in anyone's test results.


*Counter intuitively, the distance scale needs to be compressed rather than stretched.

YOU'RE AMAZING! :Kaleun_Salute: :Kaleun_Cheers: :Kaleun_Thumbs_Up:


Thank you SO much! That's fantastic!

Nathaniel B: The scale compression (or expansion) should not have been needed. An order of 10 on each scale should have the same difference in pixel coordinates. Only a horizontal shift of the distance scale would be needed to turn the yards into meters.

By how much? Draw a vertical line between the same mark on the time and speed scale. This crosses at a specific distance. Calculate what this should become: i.e. 10 kts in 10 minutes = 3086.67 meters. (=10min *10kts * 1852m/60 min)

Measure the pixel distance (on the original scan) between 3000m and 30000m.

Then the offset of the 3000m mark w.r.t. the 10kts and 10 minutes marks = ( log_10(3086.666)-log_10(3000) )*pixeldistance. The 3000m mark would come left of the vertical line so shift in the appropriate direction.

Interesting, thanks! I'm glad to receive any input that might make it more accurate. I'll mess around with it more when I have time to test more examples.

I corrected my formula above, I placed the difference of logarithms between brackets.