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gams:precision_of_data_within_gams [2007/08/17 14:22]
127.0.0.1 external edit
gams:precision_of_data_within_gams [2008/02/07 06:25] (current)
Franz Nelissen
Line 6: Line 6:
 There is also limit to the precision of these doubles - the relative error between any real number in the normalized range and the nearest representable double is at most 2.2204e-016. ​ In practice this means values will have at most 15 or 16 decimal digits of accuracy. GAMS will never print more than 15 decimals. ​ When GAMS reads numbers it will guarantee 15 digits of precision and will give an error message ($103) when getting a number with more than 16 digits, since there will be a loss of precision in storing the result and the extra digits are essentially meaningless:  ​ There is also limit to the precision of these doubles - the relative error between any real number in the normalized range and the nearest representable double is at most 2.2204e-016. ​ In practice this means values will have at most 15 or 16 decimal digits of accuracy. GAMS will never print more than 15 decimals. ​ When GAMS reads numbers it will guarantee 15 digits of precision and will give an error message ($103) when getting a number with more than 16 digits, since there will be a loss of precision in storing the result and the extra digits are essentially meaningless:  ​
   * The option $offdigit can be used to read in data which has more than 16 digits   * The option $offdigit can be used to read in data which has more than 16 digits
-  * The listing file only prints up to 8 decimals (3 by default)+  * The ''​display''​ statement ​only prints up to 8 decimals (3 by default) ​to the listing file. Use the option ''​decimals = n''​ to change it the n decimals.
   * To get maximal precision on a put statement one should ​ force '​scientific'​ format with plenty of room as shown below   * To get maximal precision on a put statement one should ​ force '​scientific'​ format with plenty of room as shown below
   * GDX in and out does not drop any precision, it takes the floating ​ point number bit by bit.   * GDX in and out does not drop any precision, it takes the floating ​ point number bit by bit.
IMPRESSUM / LEGAL NOTICEPRIVACY POLICY gams/precision_of_data_within_gams.txt ยท Last modified: 2008/02/07 06:25 by Franz Nelissen