MaplePrimes Questions


 

 

the quartile function gives the wrong answers.

list := [1,2,3,4,5,6,7,8]

Q1 does NOT come back as 2.5 as it should, nor does Q3. I get these weird decimals.

I looked at the help for it but wasn't helpful. All the examples in the help are super complicated. No simple examples like the one I mentioned here.

thanks

Hi everyone:

I have two matrices T(t) and Y[i] :N is natural.how can I do it? tnx.

 

 

 



I am just confused to be getting this error seeings FileTools does not encounter this error when I use it's ListDirectory command:

 

error_for_primes.mw
 

with(ImageTools):

FileTools:-ListDirectory(currentdir())

["IMG_20200116_015953.jpg", "magetools commands.mw"]

(1)

Read("H:\\MAPLE\\Image_Project", format = JPEG)

Error, (in readbytes) permission denied

 

NULL


 

Download error_for_primes.mw



sigma(integral(F(w,cn1,ct1))+integral(F(w,cn2,ct2))+...+integral(F(w,cn80,ct80)))

integral.mw

In a do loop with a try... catch statement I had placed an assignment to a vector element after catch: but before the line printing the lastexception. That the loop didn't perform as expected, but resulted in an error about ListTools:-FormatMessage wanting its first argument to be a string surprised me. Putting the assigment to the vector after the exception printing worked fine.
It seems that rtables are the exception (no pun intended) to the order being irrelevant.
 

restart;
V:=Vector():
for j from 1 to 5 do
  try
   V(j):=j/(j-1)
  catch:
   V(j):=17; # clears lastexception apparently
   printf(cat(StringTools:-FormatMessage(lastexception[ 2 .. -1 ] ),"\n"));
  end try
end do:
#####
restart;
V:=Vector():
for j from 1 to 5 do
  try
   V(j):=j/(j-1)
  catch:
   printf(cat(StringTools:-FormatMessage(lastexception[ 2 .. -1 ] ),"\n"));
   V(j):=17;
  end try
end do:

These simple lines confirm my observation:

restart;
lastexception;
5/0;
lastexception;
5/5;
lastexception;
x:=47;
lastexception;
table();
lastexception;
[1,2,3];
lastexception;
rtable();
lastexception; # Now cleared!


 

Hello Dear Brothers and Sistors,

Can you help me giving a maple program to plot cost function  of a an optimal control modeling ?

Looking forward.

Regards,

hi everyone:

How can I define this matrix in Maple? N is a Natural number. Thank you. 

In my maple ini I redefine I.

 

local a,b,c,I:

 

Every worksheet I create I always end up with an executed line with just "I". It's just annoying to see it as it service no purpose and takes up space at the start of the worksheet.

 

Of course I is a predefined symbol which is why I want to redefine it, redefine it to be _i, say. I've tried unprotect and unassign and all that and it still prints out.

 

Now I always put a restart at the start of a worksheet so I end up getting two lines of the I, which is a total of 4 because it prints a blank line.

 

 

 

Bonjour,
Un connaisseur pourrait-il m'aider s'il vous plaît afin de résoudre un petit problème sur Maple.
J'ai un algorithme qui me renvoie les résultats successifs des nombres utilisés pour faire une multiplication égyptienne.
Sauf que les résultats sont renvoyés sur des lignes différentes avec plusieurs références d'une liste que j'ai nommé "L".

Les résultats sont renvoyés donc ainsi :

L:= [21 , 54 , 47]
L:= [20, 41 , 87]
L:= [2, 8, 12]
L:= [3, 7 , 5]

Comment faire pour que les résultats soient regroupés dans une même liste, c'est à dire :

L:= [21 , 54 , 47, 20, 41 , 87, 2, 8, 12, 3, 7 , 5 ]


Voici l'algorithme :


x := 12:
y := 46:
s := 0;
'x' = x:
'y' = y:
'`résultat`' = s:
while 0 < y do
if type(y, odd) then s := s + x:
y := y - 1:
else x := 2*x:
y := y/2:
end if;
L := [x, y, s];
end do;


I have this results in Maple :
L:= [21 , 54 , 47]
L:= [20, 41 , 87]
L:= [2, 8, 12]
L:= [3, 7 , 5]

How do for have just one list that :

L:= [21 , 54 , 47, 20, 41 , 87, 2, 8, 12, 3, 7 , 5 ]

Hi 

I got, a bit by mistake, a weird result that seems to come from the way "Maple" manipulates infinity (please have a look at the results below)
I couldn't find a correct explanation to these results in the help pages dedicated to infinity or evaluation.

Could anyone explain me why, in some circumstances, 'infinity' seems to be a name (for instance infinity*Pi; does not return  infinity but infiniy/Pi).
Thanks in advance

 

restart:

with(Statistics):

f := PDF(Cauchy(0, 1), x)

1/(Pi*(x^2+1))

(1)

m := int(x*f, x=-infinity..+infinity);

undefined

(2)

p := int(x*f, x);

(1/2)*ln(x^2+1)/Pi

(3)

# Naive "proof" : eval(..., infinity) seems to consider infinity as a name (consistent with
# the first line in help(infinity) without any particular property.
# This seems to be confirmed by the value of p1 and p2 : I expected to get infinity instead
# of infinity/Pi.

p1 := eval(p, x=-infinity);
p2 := eval(p, x=+infinity);
p2 - p1;

infinity/Pi

 

infinity/Pi

 

0

(4)

# Correct "proof" :

a := limit(p, x=-infinity);
b := limit(p, x=+infinity);
b-a

infinity

 

infinity

 

undefined

(5)

# Does Maple treat 'infinity' as a number ?

infinity         - infinity;
infinity*2       - infinity*2;
infinity*(1/3)   - infinity*(1/3);
infinity*0.333   - infinity*0.333;
infinity*sqrt(2) - infinity*sqrt(2);
infinity/Pi      - infinity/Pi;

undefined

 

undefined

 

undefined

 

Float(undefined)

 

0

 

0

(6)

limit(sqrt(2)/x, x=0) - limit(sqrt(2)/y, y=0);
limit(Pi/x, x=0)      - limit(Pi/y, y=0);

undefined

 

undefined

(7)

 


 

Download Infinity.mw

Dear Guys

How can I plot a fieldplot with a boundary. For example I can plot

> fieldplot([y, -sin(x)-(1/10)*y], x = -1 .. 1, y = 0 .. 1);

but I want to see the field plot only in the region x^2+y^2<=1.

Thanks a lot 

timestamp is the number of seconds from the epoch, which I thought was Jan 1, 1970.  Maple uses Dec 31, 1969.  It appears there is a maximum number of seconds you can use with timestamp.

FormatTime("%Y-%m-%d", timestamp = 0)
                                                                "1969-12-31"


FormatTime("%Y-%m-%d", timestamp = 2147483647)
                                                                 "2038-01-18"

Who knows if Maple will be around then, however if we add one second more to timestamp we run into the 32 bit integer problem.

FormatTime("%Y-%m-%d", timestamp = 2147483648)
Error, (in StringTools:-FormatTime) timestamp value must be a 32-bit signed integer.

Can Maple get passed 2038 using timestamp?  Is there always that 32 bit limit?

 

I couldnt find this command in the number theory package, as far as what i am thinking of doing it should be straight forward but very long winded, so if I have missed this command throughout the packages up to Maple 2016 I would appreciate someone telling me otherwise I suppose it's what i am doing for the next few hours

https://en.wikipedia.org/wiki/Partition_(number_theory)
 

Hi,

I discovered that the option legend, when used in plots:-inequal, returns an empty graphic.
Is it a bug or a deliberate choice?

Anyways, is it possible to insert a legend in a simple way (that is without using textplot for instance)?

TIA

I am trying to find six integer numbers a, b, c, d, n, p so that this equation
abs(a*x+b)+abs(c*x+d)+x^2+n*x+p = 0
has 6 integer solutions are 1, 2, 3, 4, 5, 6. I tried
f:=x-> abs(a*x+b)+abs(c*x+d)+x^2+n*x+p;
solve([f(1) = 0, f(2) = 0, f(3) = 0, f(4) = 0, f(5) = 0, f(6) = 0], [a, b, c, d, n, p])


This equation has no solution. Is there six integer numbers a, b, c, d, n, p so that this equation has 6 integer solutions?

I have just found one solution is
solve(abs(-2*x+5)+abs(-2*x+9)-x^2+7*x-16 = 0, x);

With Mathematica, I see at here 
https://mathematica.stackexchange.com/questions/212808/find-integers-a-b-c-d-m-n-p-so-equation-has-six-distinct-solutions

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