SHAZAM Questions and Answers (Q&A) - RSS feedhttp://community.econometrics.com/questions/SHAZAM Econometrics, Statistics and Analytics Communityen<font color="white">Copyright <b>SHAZAM Analytics, 2018</b></font>Mon, 06 Jun 2011 10:58:19 +0000What is SHAZAM Quad Precision?http://community.econometrics.com/question/205/what-is-shazam-quad-precision/What is the "Use Quad Precision" mode for? It appears in the Options but there is no description in the online help.Sat, 28 May 2011 11:03:09 +0000http://community.econometrics.com/question/205/what-is-shazam-quad-precision/Answer by David for <p>What is the "Use Quad Precision" mode for? It appears in the Options but there is no description in the online help.</p>
http://community.econometrics.com/question/205/what-is-shazam-quad-precision/?answer=289#post-id-289Quad Precision is a higher precision mode of SHAZAM. Most analytical software packages (including SHAZAM) typically perform calculations in double precision but report the answer in less precision so that any accumulated rounding error is simply truncated in the reported results.
However, SHAZAM is also capable of Quadruple precision floating-point calculations where floating point numbers occupy 16bytes instead of the usual 8bytes used for double precision floating point calculations. This capability of SHAZAM is unique among the class of econometrics, statistics and analytics software that SHAZAM is part of.
Higher precision is useful when there are a lot of calculations being performed (such that rounding error accumulates to a large degree) or where source data is highly precise to begin with.
Note that Precision is different from Accuracy and measurements are usually considered valid when they are both Accurate and Precise. In optimization algorithms it is possible for higher precision internal calculations to lead to more accurate final results because tolerances are smaller.
Quadratic Precision mode is mentioned on pages 474, 475 and 477 of the SHAZAM version 10 Reference Manual.Sun, 29 May 2011 15:21:05 +0000http://community.econometrics.com/question/205/what-is-shazam-quad-precision/?answer=289#post-id-289Comment by cordul for <p>Quad Precision is a higher precision mode of SHAZAM. Most analytical software packages (including SHAZAM) typically perform calculations in double precision but report the answer in less precision so that any accumulated rounding error is simply truncated in the reported results. </p>
<p>However, SHAZAM is also capable of Quadruple precision floating-point calculations where floating point numbers occupy 16bytes instead of the usual 8bytes used for double precision floating point calculations. This capability of SHAZAM is unique among the class of econometrics, statistics and analytics software that SHAZAM is part of.</p>
<p>Higher precision is useful when there are a lot of calculations being performed (such that rounding error accumulates to a large degree) or where source data is highly precise to begin with.</p>
<p>Note that Precision is different from Accuracy and measurements are usually considered valid when they are both Accurate and Precise. In optimization algorithms it is possible for higher precision internal calculations to lead to more accurate final results because tolerances are smaller.</p>
<p>Quadratic Precision mode is mentioned on pages 474, 475 and 477 of the SHAZAM version 10 Reference Manual.</p>
http://community.econometrics.com/question/205/what-is-shazam-quad-precision/?comment=376#post-id-376thank you for your helpMon, 06 Jun 2011 10:58:19 +0000http://community.econometrics.com/question/205/what-is-shazam-quad-precision/?comment=376#post-id-376