Hi,
I used "?mtcars" to read the documentation for the dataset. I
found a
mistake in how unit is listed, namely, that for the variable "wt," the
unit
should be listed as "1000 lb," not "lb/1000." However, I
don't know whom to
contact exactly for the correction. Please point me to the right place.
Thanks.
--Ming
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Hi Ming, In fact, the notation lb/1000 is correct, as the values represent the weight of the cars in pounds (lb) divided by 1000. I am not sure why this particular transformation of the measured values was used, but I'm sure it has caused confusion previously. Jim On Sat, Oct 24, 2015 at 11:59 AM, Ming-Lun Ho <minglho at gmail.com> wrote:> Hi, > I used "?mtcars" to read the documentation for the dataset. I found a > mistake in how unit is listed, namely, that for the variable "wt," the unit > should be listed as "1000 lb," not "lb/1000." However, I don't know whom to > contact exactly for the correction. Please point me to the right place. > Thanks. > --Ming > > [[alternative HTML version deleted]] > > ______________________________________________ > R-help at r-project.org mailing list -- To UNSUBSCRIBE and more, see > https://stat.ethz.ch/mailman/listinfo/r-help > PLEASE do read the posting guide > http://www.R-project.org/posting-guide.html > and provide commented, minimal, self-contained, reproducible code. >[[alternative HTML version deleted]]
Hi Jim,
Conventionally, the units listed in a data description should represent
how to interpret the values of a variable. You would label the wt-axis in a
graph with the unit "1000 lb," so that should be the unit in the data
description. At least that is how data dictionaries in the statistics texts
I've taught from are set up.
--Ming
On Sat, Oct 24, 2015, 01:10 Jim Lemon <drjimlemon at gmail.com> wrote:
> Hi Ming,
> In fact, the notation lb/1000 is correct, as the values represent the
> weight of the cars in pounds (lb) divided by 1000. I am not sure why this
> particular transformation of the measured values was used, but I'm sure
it
> has caused confusion previously.
>
> Jim
>
>
> On Sat, Oct 24, 2015 at 11:59 AM, Ming-Lun Ho <minglho at gmail.com>
wrote:
>
>> Hi,
>> I used "?mtcars" to read the documentation for the
dataset. I found a
>> mistake in how unit is listed, namely, that for the variable
"wt," the
>> unit
>> should be listed as "1000 lb," not "lb/1000."
However, I don't know whom
>> to
>> contact exactly for the correction. Please point me to the right place.
>> Thanks.
>> --Ming
>>
>> [[alternative HTML version deleted]]
>>
>> ______________________________________________
>> R-help at r-project.org mailing list -- To UNSUBSCRIBE and more, see
>> https://stat.ethz.ch/mailman/listinfo/r-help
>> PLEASE do read the posting guide
>> http://www.R-project.org/posting-guide.html
>> and provide commented, minimal, self-contained, reproducible code.
>>
>
>
[[alternative HTML version deleted]]
On 24/10/15 21:10, Jim Lemon wrote:> Hi Ming, > In fact, the notation lb/1000 is correct, as the values represent the > weight of the cars in pounds (lb) divided by 1000. I am not sure why this > particular transformation of the measured values was used, but I'm sure it > has caused confusion previously.I disagree --- and agree with Ming. The notation is incorrect. Surely "lb/1000" means thousandths of pounds. E.g. 12345 lb/1000 is equal to 12.345 lb. I'm sure that others will come up with all sorts of convoluted lawyerish arguments that the case is otherwise, but as far as I am concerned, any *sane* person would interpret "lb/1000" to mean thousandths of pounds. If in the unlikely event that the documentation for some data set said "Weight (gm/1000)", I'm pretty sure that this would be interpreted to mean milligrams and *not* kilograms! Since the description of the data was presumably taken from that given in the original source ("Motor Trend" magazine) it would probably be inappropriate to "correct" it. However a note/warning should be added to the mtcars help file indicating that Motor Trend got things upside-down. cheers, Rolf -- Technical Editor ANZJS Department of Statistics University of Auckland Phone: +64-9-373-7599 ext. 88276> On Sat, Oct 24, 2015 at 11:59 AM, Ming-Lun Ho <minglho at gmail.com> wrote: > >> Hi, >> I used "?mtcars" to read the documentation for the dataset. I found a >> mistake in how unit is listed, namely, that for the variable "wt," the unit >> should be listed as "1000 lb," not "lb/1000." However, I don't know whom to >> contact exactly for the correction. Please point me to the right place. >> Thanks. >> --Ming