-search precision- gives a full array of references, some but not all of
which have been mentioned previously. Note in particular
FAQ . . . . . . . . . . . . . . . . . . . Results of the mod(x,y)
function
. . . . . . . . . . . . . . . . . . . . . N. J. Cox and T. J.
Steichen
2/03 Why does the mod(x,y) function sometimes give
puzzling results?
Why is mod(0.3,0.1) not equal to 0?
http://www.stata.com/support/faqs/data/mod.html
FAQ . . . . . . . . . . . . . . . . . The accuracy of the float
data type
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . W.
Gould
5/01 How many significant digits are there in a float?
http://www.stata.com/support/faqs/data/prec.html
FAQ . . . . . . . . . Comparing floating-point values (the float
function)
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . J.
Wernow
3/01 Why can't I compare two values that I know are equal?
http://www.stata.com/support/faqs/data/float.html
FAQ . . . . . . . . . Why am I losing precision with large whole
numbers?
. . . . . . . . . . . . . . . . . . UCLA Academic Technology
Services
7/08 http://www.ats.ucla.edu/stat/stata/faq/longid.htm
SJ-8-2 pr0038 Mata Matters: Overflow, underflow & IEEE floating-point
format
. . . . . . . . . . . . . . . . . . . . . . . . . . . . J. M.
Linhart
Q2/08 SJ 8(2):255--268 (no
commands)
focuses on underflow and overflow and details of how
floating-point numbers are stored in the IEEE 754
floating-point standard
SJ-6-4 pr0025 . . . . . . . . . . . . . . . . . . . Mata matters:
Precision
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . W.
Gould
Q4/06 SJ 6(4):550--560 (no
commands)
looks at programming implications of the floating-point,
base-2 encoding that modern computers use
SJ-6-2 dm0022 . Tip 33: Sweet sixteen: Hexadec. formats & precision
problems
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . N.
J. Cox
Q2/06 SJ 6(2):282--283 (no
commands)
tip for using hexadecimal formats to understand precision
problems in Stata
Nick
[email protected]
Martin Weiss
Also note the FAQ on this point:
http://www.stata.com/support/faqs/data/float.html
http://www.stata.com/support/faqs/data/prec.html
David Airey
Why does the float function not work like this? I feel silly.
clear
input float x
0.00
0.01
0.03
0.10
0.30
1.00
end
generate str4 x_str = ""
replace x_str = "0.00" if float(x) == 0.0
replace x_str = "0.01" if float(x) == 0.01
replace x_str = "0.03" if float(x) == 0.03
replace x_str = "0.10" if float(x) == 0.1
replace x_str = "0.30" if float(x) == 0.3
replace x_str = "1.00" if float(x) == 1.0
list, clean
which gave
. list, clean
x x_str
1. 0 0.00
2. .01
3. .03
4. .1
5. .3
6. 1 1.00
*
* For searches and help try:
* http://www.stata.com/help.cgi?search
* http://www.stata.com/support/statalist/faq
* http://www.ats.ucla.edu/stat/stata/
