Thanks Joe and Robert, that works nicely.

Can that also be done using Arrays? 

Thanks Joe and Robert, that works nicely.

Can that also be done using Arrays? 

Thanks!  I was trying to get map to work, looks like zip is the better option.

Thanks!  I was trying to get map to work, looks like zip is the better option.

I didn't need it for anything in particular.  I just happened to come across it and wondered why the two couldn't be differentiated from one another.  But I just thought of a particular example ... it's no different than constant Pi and the symbol pi.  So I can see now why the two can't be differentiated. 

I didn't need it for anything in particular.  I just happened to come across it and wondered why the two couldn't be differentiated from one another.  But I just thought of a particular example ... it's no different than constant Pi and the symbol pi.  So I can see now why the two can't be differentiated. 

Mine is simpler. 

The centroid command within maple requires you to label the points and then use a name, not exactly what I had in mind.  All I wanted was something simple.

even simpler (since we already know what the command is for)

Centroid2 := proc (list)
local i:
add(i, i = list)/nops(list):
end proc:

a := [[2, 3], [5, 4], [5, 6], [3, 3]]

Centroid2(a)
                                 [15/4, 4]

Maple's centroid command code is quite involved to get what you want, you need to (as I understood it) for my example set the points up so the command could use it.

with(geometry):
a:= [point(A,2,3),point(B,5,4),point(C,5,6),point(F,3,3)]:
centroid(G,a):

coordinates(G)

Thanks, but if I assign a value to xi the same value is assigned to ξ.  Can I assign different values to them. 

I had suggested to keep the order rather than to upset the order for the reasons you explain.  The most voted up answer is not necessarily the best answer for the same reason as someone suggesting what code to use is easiest.  The answer to both is subjective and up for debate. 

... just thinking now, I thought it might (hindsight is always 20-20) but just lock the old mapleprimes but keep it open for searches and have the new mapleprimes open for all new commenting/posting/questions etc... that way nothing would have been messed up and all archives would still be there ... And the new mapleprimes would start fresh with a new set of posts and a new understanding rather than to try to upset / translate the old into the new which can sometimes be problematic and difficult to both parties (the mapleprime site programmers themselves and the audience that uses the site).   

By the way, what happened to the tools of maple masters threads / structure.  And the book pages structure of the old mapleprimes.  The top ten maple errors is no longer in the book pages their listed into the tips and techniques.  I think all the levels of the book pages were put into one level there.  Unless you knew the structure of it before the structure of it now is disbanded. 

Many of the topics and subtopics that were layers deep were hidden gems that made the old mapleprimes a cool jouney.  That structure was taken away because they wanted to make it simple, but I believe mapleprimers rather liked the complexity the old forum have.  Sort of niche in the forum world and it was fast, not very good for pasting code and it had it's own share of problems.  Hopefully things can get all worked out soon with this new site.

isgoal := proc () `if`(rand() mod 100 < 95, `goal`, `no goal`) end proc:

Very impressive!  How did you create the flags?  And are they only useable in a maplet?

The eloratings.net site seems to be down for the tournament but someone is updating them on wikipedia. 

Not sure if anyone else is attempting a document but there are lots of reads.  The first round of knockouts is already half over .. wonder if someone will come up with something before the end of the tournament.  3 of my 4 teams are already knocked out.  England was robbed of a goal and had they stood with their goal keeper that mishandled a goal in the round robin I'm sure the game would have been closer.  And Mexico lost out on offside, clearly soccer needs an overhaul of the rules and replay brought in however .... I digress and that's a discussion for another place. 

As of June 25 before the knockouts began, here are the ratings from wikipedia

A simple similar recreation of the first steps taken on the mathematica worksheet.  A problem I ran into is that  Maple didn't plot if I didn't specify the x range.  And a small change is that I added gridlines.

with(plots):

f := x-> exp(-(x-alpha)/beta)*exp(-exp(-(x-alpha)/beta))/beta:

alpha:=0:
beta:=400/log(10):

a:=plot(f(x-2100),x=1000..3000,filled=true,color=yellow,transparency=0.6):
b:=plot(f(x-1605),x=1000..3000,filled=true,color=blue,transparency=0.6):
aa:=plot(f(x-2100),x=1000..3000,color=green):
bb:=plot(f(x-2100),x=1000..3000,color=blue):

display(aa, a, bb, b, axes = boxed, labels = [Performance, Probability], labeldirections = [default, vertical], title = "Elo performance distribution for Slovakia and Brazil", axis = [gridlines = [color = grey]])

**edit -- mapleprimes problems --  it appears the graphics on the right got cut off, I had to re-edit and resize .. done .. Also when pasting pictures they are thrown in at the top of the message .. (just had to copy and paste further down then delete the original).

I was unable to log into the eloratings.net site.

However, as of June 20 the eloratings for the final 16 are listed below

Maple will have a hard time with the graphics manipulation otherwise we should get started.  Final 16 starts tomorrow, time is short.   How fast can we collaborate and finish a worksheet before the end of the weekend?

The extreme value distribution in mathematica is the fisher-Tippet distribution.  Others use Gumbel as was mentioned above, also sometimes called Log-Weibull distribution.

Extreme Value Distribution function:
    f(x)=1/beta*exp(-(x-alpha)/beta)*exp(-exp(-(x-alpha)/beta))

where alpha=0 and beta=400/ln(10) in the mathematica's worksheet