sand15

350 Reputation

10 Badges

5 years, 83 days

MaplePrimes Activity


These are questions asked by sand15

Hi everybody,

I have to solve a system  of 3 equations in 3 unknowns.
One equation is linear while the others are not because of some  sinh(cste*unknown) term.
More of this the unknowns must verify some constraints of inequality type (but always very simple ; for instance “unknown <= value”).

solve fails because of the sinh terms
fsolve fails due to the inequalities


What Maple procedure do you advise me to use to solve this system ?
(at this stage I think advices could be sufficient ; if I keep coming up against the problem I will submit you a more detailed question)


Thanks in advance

 

Hi everybody,

 

Here is a very simple question :
I have two strictly positive reals r and s and the expression
a := r^2 – r*s + s^2
Obviously a is strictly positive too

But I’m not capable to prove this with Maple (2016, Windows 7), even after having declared r and s both positive which, I thought, would have prevent Maple to consider them as potentially complex.
I failed in using "is", "coulditbe", "use RealDomain ..." and so on

Totally distressed I tried to do something simpler ... which ultimately appeared still more upsetting

restart:
assume(r, ‘positive’):
coulditbe(r, ‘complex’) ;    # the answer is (surprising ?) true

I'm probably doing some mistake bigger than I but I don't find it !

Could you be compassionate enough to enlight me !!!

Mammoth thanks in advance

Hi,

This question concerns the package GraphTheory
( Maple 2015 on a Windows 7 PC )

Let G1 be some graph and V a list of vertices in G1
The default colors DrawGraph uses for the vertices is yellow

I define the graph G2 this way :
    G2 := copy(G1):
    HighlightVertex(G2, V, red);
    DrawGraph(G2);
Obviously the result is a graph where vertices in V are red while the remaining ones are still yellow

Question 1 :  Why does the command DrawGraph(G1) returns exactly the same picture ?
I have thought that defining G2 as a copy of G1 would have preserved the default colouring of the vertices.
Note that the same undesired (at least for me) thing occurs with the  HighlightEdges command.

Question 2 : Is it possible to retrieve the original colouring of G1 without using HighlightVertex(G1, V, yellow)  ?

Thank you in advance

Morning all,

I repeatedly solve (command solve) a collection of systems of inequalies. Some of them can have no solution, but I am able to check if a solution has been found or not, and then take some decision about the system in question.

I have placed a few print commands at different critical locations within the loop where those systems are constructed and possibly solved.
Every time solve fails finding a solution it returns me a "no solution found" warning.
In order to keep my printings readable, could it be possible to avoid those warnings ?
Is there some "try & catch" like mechanism to manage warnings ?

Thank you all in advance

Hi everybody, 

Neither of these questions is vital but answers will be greatly appreciated

-------------------------------------------------------------------------------------------------
Question 1 :
Is it possible to manage programatically the character fonts in a printf command ?
(for instance to print some piece of text in bold font ... without selecting it and clicking the bold B of the toolbar)

-------------------------------------------------------------------------------------------------
Question 2 :

In order to have a nice render, I use to create my own format for printf command. For instance, when I have to “printf” some text I usually compute its length L and my “printf” format constructor contains a command  like  MyFormat := cat(“%”, L, “a”)

Unfortunately the length(…) command seems to be sensitive to accented characters :
                                     For people not familiar with french, "dégénéré"  (note the acute accents) means "degenerate".
length(“dégénéré”) returns 12
length(“degenere”) returns 8
… which of course leads to a very inelegant render, which is all I wanted to avoid

Why does “length” behave this way ?
Is it possible to bypass this annoyance while ensuring “dégénéré” has length 8 ?



Thanks in advance

 

First 11 12 13 14 15 16 17 Page 13 of 18