Talk:Truncation

This needs a link to floor function. Is it the same for negative numbers?

Quality Of English

"like when someone uses only the first few terms of an infinite series, or when one calculates an integral by approximating the area by finite trapezoids, or when the derivative of a function is found by using a finite deltax"

I dislike the use of "like", as well as this drawn on sentence. Could someone with more insight into the expected standards for English on Wikipedia please correct this? Thanks. —Preceding unsigned comment added by 64.230.94.119 (talk) 05:08, 5 January 2008 (UTC)

TeX

Hi, i just added the TeX and Rounding/floor function info. I made it easy myself by only allowing to use positive real numbers to be truncated. If you are shure it can be done for any real number, go ahead. --Abdull 16:57, 8 March 2006 (UTC)

I think truncation is referred to as truncating a mathematical procedure, like using a finite number of terms in an infinite series, or approximating an integral as a trapezoid, etc. What is referred as truncation in wikepedia is called chopping. Truncation and round off and chopping are used interchangeably so much that it can be confusing to the reader.

More general

In mathematics, truncation is the term used for reducing the number of digits right of the decimal point [...]

Generally speaking, you can also truncate a value before the decimal point. Truncating 817.23 two digits before the decimal point will make 800. --Abdull 17:06, 8 March 2006 (UTC)

Expanding Article

Would it be appropriate for this article to be expanded by including a mention and definition/discussion of chopping? Cah says doom (talk) 09:25, 24 October 2008 (UTC)

Meanings beyond mathematics.

I must point out that right or wrong the concept of truncation extends well beyond mathematics in it's common use in the English language.

Indeed, I don't believe it is a math derivative word, but rather a word used in mathematics.

The archaic definition of the word truncate simply means 'to lop' or to 'chop off'. Even the dictionary.com entry shows it's first definition to be the more general use of the word and the second to be it's use in mathematics or in programming, and then finally, it's biological connotation.

See here: http://dictionary.reference.com/browse/truncate

As such, this article should begin with the general and then perhaps expound on the mathematic specifics leaving the option for others to add the other common usages, or it should be a disambiguation page referencing separate pages on these topics.

Cheers.--Thistledowne (talk) 06:30, 18 November 2008 (UTC)

Thisledowne, please keep in mind that Wikipedia is not a dictionary. The many meanings of the word 'truncation' are not the topic of this article. If there are other encyclopedic meanings of truncation (I can't think of any), then they should have their own articles. The dictionary entry you reference suggests the adjective "truncate" means something specific in biology -- I don't know if there's anything encyclopedic there, but if there is, perhaps it deserves its own article. --macrakis (talk) 07:53, 18 November 2008 (UTC)

Opposite

Okay, truncation is removing digits to the right of the decimal, but what is it called when you remove to the left? I thought that'd be mentioned here. 161.184.230.55 (talk) 09:12, 25 August 2010 (UTC)

Truncation vs. Rounding vs. Floor

The article refers to rounding when dealing with negative numbers. But truncation isn't rounding. Someone should find a better way to explain it.

As described in the article, "rounding" towards zero would produce a counter-intuitive result for negative numbers. Truncating 123.45 would produce 123, while truncating -123.45 would produce 124.

For illustrative purposes, note the behavior of a C program that casts a float to an int (essentially a truncation operation):

 #include <stdio.h>
 
 int main(void) {
   float f = 123.45;
   float g = -123.45;
   printf("%d\n", (int)f);
   printf("%d\n", (int)g);
   return 0;
 }

The output is:

 123
 -123