## 189 Reputation

16 years, 255 days

## MaplePrimes Activity

### These are answers submitted by maplenoob

ah ok......what a bad luck to choose such digits :)

thx for your help, for other numbers it really takes longer.....

but where did you find the information about igcd ? i tried to google the name Weber but i found just pages where it is mentiond that this guy made a gcd implementation but i couldn't find a pseudocode (or a real implementation).......

do you have info why maple use this (slow) algo?

## i use a 2.4 GHz system (core...

i use a 2.4 GHz system (core duo, does maple 11 take advantage of multi-core systems?).

the implementation i used for the euklid algo is the one that is written on wikipedia. here a link to my worksheet with my code. at the end the runtime of each algo is printed:

btw.
where did you find the information on igcd ? maple help didn't give me clue ???

## for example: igcd(150000!,...

for example:

igcd(150000!, 250000!)

(real big numbers), this example needs on my maschine for example 7 seconds do be solved. my euklid-implementation needs just 0.3 seconds !

## . if i use tallyInto with...

. if i use tallyInto with the "default" value maple splits my values in 5 groups like i wanted it, but i don't unterstand why my first attempt was wrong.

Regarding the frequency function: I need to know the function itself not a table of it nor a Plot how do i get the function?

## thank you so far, i still...

```thank you so far, i still have a problem. i would like to have an ouput that tells me the binary code for the single letters i use for example e= 00 f= 010 d=100 g=110 and so on
I tried to solve that problem by adding the 0 and 1 to an listlist and record my binary code for each letter. but whatever i am doing it doesn't seems to be fine with the maple syntax.

compare := proc(a::list,b::list) #Sortieren
evalb(a[2] > b[2])
end proc:

ShannonFano := proc(L :: listlist, Q :: listlist)
local n,k,i,q,v,tot,cumul;
n := nops(L);

if n < 2 then
print(Q);
return L[];
end if;

tot := add(v[2], v in L);
cumul := 0;

for k to nops(L) while cumul < tot/2 do
cumul := cumul + L[k,2];
end do;

print("New Node: ", L);

if nops(L[1..k-1]) = 1 then
print("Leaf");
end if;
print("0",L[1..k-1]);

for i from 1 to nops(L[1..k-1]) do        #add 0 to the letters that are reached with 0
for q from 1 to nops(L[1..k-1]) do
if Q[i,1] = L[q,1] then
Q[1,2] := cat(Q[1,2], "0");
print(Q);
end if;
end do;
end do;

if nops(L[k..n]) = 1 then
print("Leaf");
end if;
print("1",L[k..n]);

for i from 1 to nops(L[k..n]) do            #add 1 to the letters that are reached with 1
for q from 1 to nops(L[1..k-1]) do
if Q[i,1] = L[q,1] then
Q[1,2] := cat(Q[1,2], "1");
print(Q);
end if;
end do;
end do;

[procname(L[1..k-1],Q), procname(L[k..n],Q)];

end proc:

listA :=[[a,41],[b,33],[c,23],[d,25],[e,100]]:
listB := sort(listA, compare);
listC := [[a,{}],[b,{}],[c,{}],[d,{}],[e,{}]]:
ShannonFano(listB,listC);

```

Maple tells me that i use formal parameters wrong. what am i doing wrong with the listlist syntax?

## thank you for your...

looks like it work, just one question

tot := add(v[2], v in L);          #1
cumul := 0;
for k to nops(L) while cumul < tot/2 do       #2
cumul := cumul + L[k,2];
end do;

what exactly does command #1 do? why do you access v with an index ? i suppose you just count the total amount of elements in my listlist?

in the for-loop you split up the list in 2 parts, but what does L[k,2] do? you take the list at position k in length 2 ? until you reach the half list of the whole list (tot/2) ? is that right?

(i am unsure about the maple commands you used the help function didn't give me satisfying answers...)

i uploaded my worksheet, the forum messed up my posting

http://www.mapleprimes.com/files/6941_shano.mw

## thx. i've to solve the this...

thx.

i've to solve the this exercise on paper too. But i have problems to getting started with my function "a*exp(-x)+b*t"

till now i only solved linear functions on paper, so i don't know how to start with this one? can you help me?

## thx so far. i used the...

thx so far.

i used the result i get from Exponentialfit to check whether the values i get fits to the plot i created

x := <0.0, 1.0, 2.0, 3.0, 4.0, 5.00, 6.00, 7.00, 8.00, 9.0>:
y := <4.1, 1.3, 0.4, 0.3, 0.1, 0.08, 0.07, 0.06, 0.08, 0.1>:

rtn := Statistics:-ExponentialFit(x,y,t);
u := op(1,rtn);
v := op(2,rtn);
evalf(u*exp(-x[1])+v*x[1]); ~1.309987037 (should be close to the original value(4.1) but 1.3 is far away)

what am i doing wrong?

## ok thank you. if've another...

ok thank you.

if've another exercise with a exponential-funktion

f (x) = ue^(-x)+vx

i tried it like that:

x := <0.0, 1.0, 2.0, 3.0, 4.0, 5.00, 6.00, 7.00, 8.00, 9.0>:
y := <4.1, 1.3, 0.4, 0.3, 0.1, 0.08, 0.07, 0.06, 0.08, 0.1>:

p1 :=plots:-pointplot([seq([x[i],y[i]],i=1..9)]): ##Plot points(Measured values )
sol2 := CurveFitting:-LeastSquares(x,y,t); ## get optimal val

so far so good but how do i get maple to draw the "new" optimized line ?

i tried but i didn't figured out how to make it.

btw.

how does maple know which function should be used? i just use "LeastSquare" and get the (right?) result.

## it is a homerwork exercise...

it is a homerwork exercise and have to solve this on paper without maple, my problem is that i don't know how to get started with this function y = f(x) = k * 2^(bx)

my prof gave the advice to do "something" with ln/lg/ld with this function but i didn't get what i ve to do with it.

## thanks. but i suppose i...

thanks.

but i suppose i didn't understand this "least square"-topic

i expected that maple would give me new points which would represent the "best" line that proceed closest to all my measure points.

what exactly is the result maple gave me?

## hm.... don't get it. where...

hm....

don't get it. where do you see 2 - 5/4 ?

>" polynomial does not read `1/4*(x - 5)`, but only `1/4*x`."

its f(x) + (f'(x)/1!)(x-xo)^1 + (f''(x)/2!)(x-xo)^2 + (f'''(x)/3!)(x-xo)^3, isn't it?!

## my vector is b :=...

my vector is b := Vector([10,20,30]); i want to rotate my vector 10 degrees on x-axis. my x-axis rotation matrix: a:= 10*(2*pi/360); # 10 degrees Rx := Matrix([[1,0,0],[0,cos(a),-sin(a)],[0,sin(a),cos(a)]]); Rx.b my result looks like this: http://i105.photobucket.com/albums/m239/souljumper/Clipboard02-3.jpg i suppose the result displays my rotated vector, but how do i force maple to display the result as a normal float-point vector. i don't like how the result looks now with the whole cos() and sin() .....(even it is more precisely).

## ah, ok. thx. another...

ah, ok. thx. another question. i have a point/vector which i have to rotate 10 degree on the x-axis but i don't know how to key in the vector matrix multiplication to get my rotated vector. what command do i have to use and what order(vector first or matrix first)? thx for help
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