From WeBWorK_wiki
Revision as of 14:01, 16 January 2010 by Pearson (talk | contribs)
Jump to navigation Jump to search

Formatting Decimals: PG Code Snippet

We show how to format decimals for display in PG problems. Note that these are insertions, not a complete PG file. This code will have to be incorporated into the problem file on which you are working.

Problem Techniques Index

PG problem file Explanation

Initialization: Standard.

$b = random(3,7,1);
# log is natural log, and ln is also natural log
$a = sprintf("%0.3f", log($b)/log(10) );

Setup: Use perl's sprintf( format, number ); command to format the decimal. The "%0.3f" portion truncates after 3 decimal places and uses zeros (not spaces) to right-justify. For answers involving money, you should set "%0.2f" for two decimal places and zero filling (for example, sprintf("%0.2f",0.5); returns 0.50). You can do a web search for more options to perl's sprintf, and also for WeBWorK's If you do further calculations with $a, be aware that numerical error may be an issue since you've reduced the number of decimal places.


\( $a = \) \{ ans_rule(20) \}


Main Text: Display the formatted number.

ANS( $a->cmp() );

Answer Evaluation: Standard.

Problem Techniques Index