It's a simple example of truncation.
Rounding measurements
- Thread starter gar
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MAC702
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- Clark County, NV
Yes, and also of rounding, but not of a result of a calculation nor of an application of the principle. I'm confused how you thought it addressed my statement. Sorry.
gar
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171125-1931 EST
Within my black box of post #32 there are at least two ways that I can perform the specific rounding operation of rounding Up or DOWN.
One method uses calculations based limits and comparisons, and the other method uses truncation with a bias.
Both methods provide an identical input to output relationship.
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Within my black box of post #32 there are at least two ways that I can perform the specific rounding operation of rounding Up or DOWN.
One method uses calculations based limits and comparisons, and the other method uses truncation with a bias.
Both methods provide an identical input to output relationship.
.
MAC702
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- Clark County, NV
gar
Senior Member
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- Ann Arbor, Michigan
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- EE
171125-2340 EST
Suppose the shims increment by about 0.0007868", and the machine is an inch based machine, then how would you go about rounding the shim call to select a shim?
Also how would you label the shims to identify them?.
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Suppose the shims increment by about 0.0007868", and the machine is an inch based machine, then how would you go about rounding the shim call to select a shim?
Also how would you label the shims to identify them?.
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It isn't. They are quite different things
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- Retired PV System Designer
Normalize the full precision measurement to a multiple of the shim increment size. Then round or truncate as directed by the designer to get the proper shim size?
Or take the resulting number and add or subtract a specified offset before rounding or truncating.
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Tony S
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Indiana General Assembly bill 246. In 1897 Indiana decreed that π = 4.
gar
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- Ann Arbor, Michigan
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- EE
171126-0704 EST
The number 0.0007868 derives from the exact ratio 25.4/1 .
That this exact ratio be used as the standard was proposed, circa 1930, by C. E. Johansson. But this exact ratio did not become the official standard until 1959. Johansson's brother-in-law, Charlie Anderson, was a good friend of my father. One time when I was in high school Charlie Anderson took me down in the basement of the Ford Engineering Lab and showed me how he made and gaged the Johansson blocks.
Some interesting references:
http://nvlpubs.nist.gov/nistpubs/jres/112/1/V112.N01.A01.pdf
This has considerable discussion on Johansson and 20 deg C.
The following are quite redundant between each other https://en.wikipedia.org/wiki/History_of_measurement
https://en.wikipedia.org/wiki/Engli...ore/factsheets/history-of-length-measurement/
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The number 0.0007868 derives from the exact ratio 25.4/1 .
That this exact ratio be used as the standard was proposed, circa 1930, by C. E. Johansson. But this exact ratio did not become the official standard until 1959. Johansson's brother-in-law, Charlie Anderson, was a good friend of my father. One time when I was in high school Charlie Anderson took me down in the basement of the Ford Engineering Lab and showed me how he made and gaged the Johansson blocks.
Some interesting references:
http://nvlpubs.nist.gov/nistpubs/jres/112/1/V112.N01.A01.pdf
This has considerable discussion on Johansson and 20 deg C.
The following are quite redundant between each other https://en.wikipedia.org/wiki/History_of_measurement
https://en.wikipedia.org/wiki/Engli...ore/factsheets/history-of-length-measurement/
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MAC702
Senior Member
- Location
- Clark County, NV
Sheesh.
If you round 3.14159265359 to the nearest whole number you get 3.
If you truncate 3.14159265359 to a whole number you get, wait for it, 3.
So, yes, while they are "quite different things" we are all still wondering what your rounding/truncation of pi has to do with it.
gar
Senior Member
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- Ann Arbor, Michigan
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- EE
171126-1930 EST
In post #45 I tossed out what could be a real world problem for an electrician in an automotive plant.
This plant normally runs parts based on English measurements. For simplicity one wants to use simple numbers. For an automotive rear axle it is typical to use shims that increment by 0.001" for positioning the pinion.
The 0.001" increment is sufficiently small to accomplish the desired build quality and can be viewed as an integer. Integers are simpler for the brain and machine to work with.
The increment number I provided in #45 is the inch value of 0.02 mm. In the same application but built with a metric design one would choose this increment for the same reasons 0.001" is selected in the English system.
GoldDigger provided a way to work with this increment, and change very little. Another approach is to take the English measurement and multiply by 25.4 and then round based on the 0.02 increment.
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In post #45 I tossed out what could be a real world problem for an electrician in an automotive plant.
This plant normally runs parts based on English measurements. For simplicity one wants to use simple numbers. For an automotive rear axle it is typical to use shims that increment by 0.001" for positioning the pinion.
The 0.001" increment is sufficiently small to accomplish the desired build quality and can be viewed as an integer. Integers are simpler for the brain and machine to work with.
The increment number I provided in #45 is the inch value of 0.02 mm. In the same application but built with a metric design one would choose this increment for the same reasons 0.001" is selected in the English system.
GoldDigger provided a way to work with this increment, and change very little. Another approach is to take the English measurement and multiply by 25.4 and then round based on the 0.02 increment.
.
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