formatting numbers in sagetex

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I worked on a ticket to help with this a while ago: http://trac.sagemath.org/sage_trac/ti...

You can see a comment from Carl Witty that gives a good approach: (I really like his option 1). Basically, it allows for setting options for printing any numbers from a RealField.

For an individual number, you're looking for the skip_zeroes argument to str:

sage: a=1.2
sage: a
1.20000000000000
sage: a.str(skip_zeroes=True)
'1.2'

Alternatively, this is the default behavior for python floats (as opposed to Sage floating point numbers), so if you either turn off the preparser or use python floats, you'll get what you want:

sage: float(1.2)*x
1.2*x
sage: preparser(False)
sage: 1.2*x
1.2*x

I find that the easiest way to to convert to a python floating point before printing.

float(24/5)          #-> 4.8
"%.4f" % float(26/3) #-> 8.6667

Depending on the type of calculations, you might be able to work in RDF, for example, or in `RealField(23)`, replacing 23 by whatever number gives you the desired precision.

Try \sage{(1.2).n(6)*V}. The .n(6) command specifies the number of significant bits used to represent the number. As a rule of thumb 3 bits ~ 1 digit.