On Thu, 24 Jun 2010, Jeffrey Hankins wrote:
< Okay...I cannot for the life of me figure out what is wrong with my code. The functions finalgrade and needgrade are supposed to reverse one another, but this is
< not what happens when I actually execute them. If anyone can read Maxima program code, I would be interested if they could tell me where I went wrong (unless it's
< a Maxima issue). finalgrade seems to be all right; the problem could be the if part of needgrade. This is pretty discouraging, especially considering that I
< haven't programmed in Maxima for very long.
<
< load(descriptive);
<
< drop (L,n) := if n=1 then delete(mini(L),L,1) else drop(drop(L,n-1),1);
<
< replace (L,x) := if x>mini(L) then cons(x,drop(L,1)) else L;
<
< finalgrade (dq,midterm,final) := ([fg],
< dq: drop(dq,2),
< midterm: replace(midterm,final),
< fg: 3*sum(dq[i],i,1,13)/13+(midterm[1]+midterm[2])/5+3*final/10,
< if fg>=89.5 then print("student got an A")
< elseif fg>=84.5 then print("student got a B+")
< elseif fg>=79.5 then print("student got a B")
< elseif fg>=74.5 then print("student got a C+")
< elseif fg>=69.5 then print("student got a C")
< elseif fg>=66.5 then print("student got a D+")
< elseif fg>=59.5 then print("student got a D")
< else print("student got an F"), fg)$
<
< needgrade (dq,midterm,desired) := ([need,lower,cutoff],
< dq: drop(dq,2),
< lower: lmin(midterm),
< cutoff: 3*sum(dq[i],i,1,13)/13+(midterm[1]+midterm[2])/5+3*lower/10,
< if desired>cutoff then block(
< drop(midterm,1),
< need: 2*(desired-3*sum(dq[i],i,1,13)/13-midterm[1]/5))
< else need: 10/3*(desired-3*sum(dq[i],i,1,13)/13-(midterm[1]+midterm[2])/5),need)$
<
<
Jeffrey,
To create an environment with local variables, use
block([x], ...)
The construction
([x], ...)
evaluates the list [x], and then the subsequent expressions.
Could you send an example that shows what your code produces
and what you would like it to produce?
Leo
--
The University of Edinburgh is a charitable body, registered in
Scotland, with registration number SC005336.