## Forum archive 2000-2006

### Mark Schmitt - Strange display error ### Mark Schmitt - Strange display error

by Arnold Pizer -
Number of replies: 0 Strange display error topic started 9/27/2002; 3:48:39 AMlast post 9/28/2002; 4:34:39 AM Mark Schmitt - Strange display error 9/27/2002; 3:48:39 AM (reads: 801, responses: 3) I have b and d as non_zero_random(-10,10,.01). a and c are random(5,9,.01). When I try to display $$a x ? {b} = c x ? {d}$$, the last digit of $d disappears, but the last digit of$b is fine. Any idea what the issue might be? I have solved the issue temporarily by changing the problem to $$a x ?{b} = d + c x$$, but I would like to know if I should worry about the way additive problems are displayed. Thanks. Mark <| Post or View Comments |> John Jones - Re: Strange display error 9/27/2002; 5:43:36 PM (reads: 984, responses: 0) Mark, I can't reproduce the problem. What happens if you use: BEGIN_TEXTMy equation is $$a x +b = c x +d$$.END_TEXT John <| Post or View Comments |> Mark Schmitt - Re: Strange display error 9/28/2002; 3:14:32 AM (reads: 964, responses: 0) If I use that code, all the digits are displayed, but if $d or$b < 0, I see: 4.52x +-5.21 = 3.27x +-4.31. That is just as hard to read. I like the ability to have the right sign displayed without the extra +. But, as I said, I have a work around, by just putting the constant first. Mostly I'm wondering if this happens elsewhere. Mark <| Post or View Comments |> Michael Gage - Re: Strange display error 9/28/2002; 4:34:39 AM (reads: 977, responses: 0) Hi all, I have some sample code below, followed by it's output (on my machine) which may help explain these "features". You should also look at the description of the BEGIN_TEXT/END_TEXT construction at http://webwork.math.rochester.edu/docs/docs/pglanguage/tutorial/problemtext.html and the description of FEQ (which stands for 'Format EQuation'). In general the ? and ! constructions are legacy constructions and do not need to be used. The fact that ? defaults to formatting numbers in %4.3g notation is, I believe, what was puzzling Mark. (%4.3g appears to mean: 3 digits total in the result.) Hope this helps. --Mike DOCUMENT(); # This should be the first executable line in the problem.loadMacros(PGbasicmacros.pl,PGchoicemacros.pl,PGanswermacros.pl,PGauxiliaryFunctions.pl);$a= -1.1234;$b= -2.1234;$c= -3.1234;$d=-49876000000.1234;BEGIN_TEXTI get the following results:$PARA: $$a x ? {b} = c x ? {d}$$$PARB: $$a x ? {b:%4.1g} = c x ? {d:%4.3g}$$$PARThe following is the preferred syntax (within "BEGIN_TEXT/END_TEXT" blocks, or anywhere else that filters TeX modes through FEQ.$PARC: $${a}x + b = {c}x+d$$$PARD: $${a:%0.2f}x + {b:%0.2g} = {c:%0.1e}x+{d:%0.1g}$$$PARFinally three examples outside of the BEGIN_TEXT/END_TEXT blocks. The last version is exactly how the BEGIN_TEXT/END_TEXT blocks are defined. Why the previous line needs to be different is beyond me. I read it as an inconsistency of perl's handling of backslashes, but perhaps I'm missing something.$PAREND_TEXTTEXT(" \$$a x ? {b:%0.3f} = c x ? {d:%0.3f} \$$",$PAR);TEXT(FEQ(" \$$a x ? {b:%0.3f} = c x + {d:%0.3f} \$$"), $PAR);TEXT(EV3('\$$a x ? {b:%0.3f} = c x + {d:%0.3f} \$$'),$PAR);TEXT(EV3(<<'EOF'),\$PAR);$$a x ? {b:%0.3f} = c x + {d:%0.3f}$$EOF I get the following results: A: -1.1234 x - 2.12 = -3.1234 x - 4.99e+10 B: -1.1234 x - 2 = -3.1234 x - 4.99e+10 The following is the preferred syntax (within "BEGIN_TEXT/END_TEXT" blocks, or anywhere else that filters TeX modes through FEQ. C: -1.1234x - 2.1234 = -3.1234x - 49876000000.1234 D: -1.12x - 2.1 = -3.1e+00x - 5e+10 Finally three examples outside of the BEGIN_TEXT/END_TEXT blocks. The last version is exactly how the BEGIN_TEXT/END_TEXT blocks are defined. Why the previous line needs to be different is beyond me. I read it as an inconsistency of perl's handling of backslashes, but perhaps I'm missing something. ( -1.1234 x ? {-2.1234:%0.3f} = -3.1234 x ? {-49876000000.1234:%0.3f} ) ( -1.1234 x - 2.123 = -3.1234 x - 49876000000.123 ) -1.1234 x - 2.123 = -3.1234 x - 49876000000.123 -1.1234 x - 2.123 = -3.1234 x - 49876000000.123 <| Post or View Comments |>