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2007.12.10 02:10 "Re: dpi settings", by Ron Croonenberg
wow a lot of discussion here... what about: http://www.ansi.org/ http://www.nist.gov/ And you'll see that the unit for distance in the metric system is the meter. The unit for distance in the standard system is foot. things like mm (mili-meter) cm (centi meter) etc are part of the system and for sure not deprecated. (deci means 1/10, centi 1/100 milli 1/1000 etc. deca means 10, hecto means 100 and kilo means 1000). cm's, nor mm's are deprecated, it is simply the term for 1/100 of a meter (or 1/1000 resp.). The reason why there are no meter marks on a ruler and no millimeter 'posts' along the free way is the same as why tweezers don't weigh 10 lbs (appr. 4.8Kg). It's clumsy to work with. rulers over here a lot of times have both scales. metric on one side and standard on the other. (1" = 2.54 cm approx. btw) mm's and cm's are just used for convenience, they are not the standard unit. (that is 1 meter). Rainfall in meters, ven though the unit is the correct one, would simply have too many leading zero's As far as it comes to "partially successful" well... only the US and the United Kingdom uses something else than the metric system. (that is les than 300 million people out of 6 billion or so). I wouldn't call that 'partially' successful. Besides, in Science, medicine etc etc the metric system is the system of choice. (It became too expensive to watch rovers pass by mars because of a calculation errors I suppose) just my 2cts (that's metric again, 100 per $) Ron Graeme Gill wrote: > Bob Friesenhahn wrote: >> Here in the US, the ruler that I have available is marked with inches >> and centimeters. Are you saying that rulers in the rest of the world >> are no longer marked with centimeters? If they are not marked with >> centimeters, then what are they marked with? A ruler marked with >> millimeters or meters would not be so convenient. > > I'm saying that for some time, cm is a deprecated unit, > and mm is the preferred unit. Yes, many rulers > sold here are marked only in mm (although, naturally the > markings are at 10mm intervals :-) In some senses this is > a subtle distinction, but it's still an irritation to > be converting to/from cm, and adds possibly confusion > and room for misunderstanding. > >> It seems natural that centimeters was used since it is easiest to >> measure the width and height of a computer screen or page-sized object >> (e.g. sheet of paper) in centimeters rather than in meters or >> millimeters. > > I know what you mean and had a similar reaction myself initially, but it > turns out in practice that mm is pretty convenient, especially for paper > size, which is where I trip over the cm/mm thing all the time with desktop > applications. It's a whole number with adequate precision for very many > everyday tasks (woodworking is another one that springs to my mind). For > grosser scales, a one digit decimal on the meter is often the way to go > (ie. 3.1 meters). It's true though that in advertisements, cm is used for > TV display sizes. I guess for screen rulings and pixel density pixels/mm > isn't so great, although it is something I've standardized on internal in > my software (reduces my confusion). > > In much official usage (ie. rainfall - when there is any!), mm are what's > used. It's hardly uniform amongst the population - when the metric system > was introduced here we were taught cm, since they where closer in size > to inches, but since then there has been an attempt to standardize on > prefixes that are a multiple of 1000, that's been partially successful. > > I think that Andrey's observation about technical and non-technical > use probably reflects the situation here in Australia as well to a fair > degree, and it will come down to what's currently being taught in > schools as to what future trends in popular usage are. > > Graeme Gill. > > _______________________________________________ > Tiff mailing list: Tiff@lists.maptools.org > http://lists.maptools.org/mailman/listinfo/tiff > http://www.remotesensing.org/libtiff/ -- ================================================================= Ron Croonenberg | | Phone: 1 765 658 4761 Lab Instructor & | Fax: 1 765 658 4732 Technology Coordinator | | Department of Computer Science | e-mail: ronc@DePauw.edu DePauw University | 275 Julian Science & Math Center | 602 South College Ave. | Greencastle, IN 46135 | =================================================================