I want a chart that explains and converts hills in different "languages".
ie,
1 in 3 33% 18,43°
Can anyone clarify an easy system for calculating these three different systems if no website/java script already exists....
To convert from a fraction to a percent grade, divide: 1/3 = .33 = 33%.
To convert from a decimal fraction to an angle in degrees, take the inverse tangent ("arctangent"😉: atan(.33) = 18.43 degrees. If your calculator displayed 0.3218 instead, then you're in radians mode; either set your display for degrees mode or multiply the result by 180/pi (about 57.32). -- Ben Pfaff email: [email hidden] web: http://benpfaff.org
To convert from a fraction to a percent grade, divide: 1/3 = .33 = 33%.
To convert from a decimal fraction to an angle in degrees, take the inverse tangent ("arctangent"😉: atan(.33) = 18.43 degrees.
Yep, I got that after a little work in Excel. The thing is that working out your own forumlas for these things is usually unnecessary because someone else has more than likely already uploaded a java script somewhere...
Some time a go I worked out a conversion chart for gears to gear inches and gear metres based on tyre size and number of sprockets. It took some tweaking and just before I finished it someone pointed me to a working java script on a website which was even better than the one I was working on.
In this case for hills I used Excel and...
ARCTAN(1/x)*180/PI()
(Where x is value in the "one in x" phrase).
So a one in ten is 5.71°
Thanks for your feedback. I still think it is strange that I could not find any websites explaining the different hill measurments used.
It currently only calculates grade in percentage, because that seems to be (by far) the most common way of describing grade. I could enhance this feature with degrees, or "1 in x", but are these alternative grade descriptions at all common? All I've ever seen in my travels is grade stated in percentage terms, but perhaps those alternative descriptions are used in some places.
It currently only calculates grade in percentage, because that seems to be (by far) the most common way of describing grade. I could enhance this feature with degrees, or "1 in x", but are these alternative grade descriptions at all common? All I've ever seen in my travels is grade stated in percentage terms, but perhaps those alternative descriptions are used in some places.
In Hong Kong steep hills have signs which indicate grades as, for example, "1:6" or "1:8" placed on top of a picture of a right-angled triangle. They probably acquired this habit from the UK, where I recall seeing signs in this form as well, so I wouldn't be surprised if this was common at least in countries where the UK once had influence.
When I was in engineering school, long ago, we used to refer to the slopes of things like tunnels and shafts in mines, which could be steep, in degrees. I think this avoided the small awkwardness of talking about near-vertical slopes as a percentage approaching infinity.
"Dennis Ferguson" <[email hidden]> wrote in message news:[email hidden]...
Quoted message said:
GaryG garyg@shasta_SPAMBEGONE_software.com said:
It currently only calculates grade in percentage, because that seems to
be
Quoted message said:
Quoted message said:
(by far) the most common way of describing grade. I could enhance this feature with degrees, or "1 in x", but are these alternative grade descriptions at all common? All I've ever seen in my travels is grade stated in percentage terms, but perhaps those alternative descriptions
are
Quoted message said:
Quoted message said:
used in some places.
In Hong Kong steep hills have signs which indicate grades as, for example, "1:6" or "1:8" placed on top of a picture of a right-angled triangle.
They
Quoted message said:
probably acquired this habit from the UK, where I recall seeing signs in this form as well, so I wouldn't be surprised if this was common at least in countries where the UK once had influence.
When I was in engineering school, long ago, we used to refer to the slopes of things like tunnels and shafts in mines, which could be steep, in degrees. I think this avoided the small awkwardness of talking about near-vertical slopes as a percentage approaching infinity.
Dennis Ferguson
Interesting...thanks. As time permits, I'll add that (and degrees) to the Grade Calculator in CycliStats.
"Dennis Ferguson" <[email hidden]> wrote in message news:[email hidden]...
[snip]
Quoted message said:
In Hong Kong steep hills have signs which indicate grades as, for
example,
Quoted message said:
"1:6" or "1:8" placed on top of a picture of a right-angled
triangle. They
Quoted message said:
probably acquired this habit from the UK,
[snip]
Here in the UK there are some gradients given in %, but most of them are still in the form 1 in something. They seem to calculate only to the nearest whole number, 1:4, 1:3 etc and the % signs are obviously straight conversions of the old system, so a sign will be 25% or 33%, never, apparently, anything in between. Some roads can get pretty steep, being originally graded for trains of pack horses, but 33% is, I think the limit.