On Wed, 16 Sep 2009, Gerhard Brunthaler wrote:
< Thanks a lot for you tip on plotting severeal curves with a loop at
< http://www.math.utexas.edu/pipermail/maxima/2006/002796.html
<
< f(n) := block(
< [curves : [], i],
< for i:1 thru n do curves : cons(x^i, curves),
< plot2d(curves, [x,-1,1])
< )$
<
< It helped me already a lot, but I have a question in order to understand
< what's going on.
<
< Why the statement with i in:
<
< [curves : [], i],
block([curves:[],i], ...)
sets up curves and i as variables local to the block, and initializes
curves to the empty list.
<
< it works also with just:
<
< curves : [],
This creates curves as a global variable.
<
< which creates an empty list. What is it good for to add the ", i]" ?
Since you probably don't need either variable outside of the block, it
makes sense to have them local variables.
This behaviour is documented in maxima's online help via
? function
or in section 39 of the user documentation.
Leo
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