MaplePrimes Questions

Given my gender, my age, the region where I live, statistics say my life expectation is still 25.3 years, thus about 221650 hours.
Under these conditions, what does the loss of an hour to answer a question represent?
Practicaly nothing, particularly if the answer does present some interest for the OP who posted it.

But what if this same OP has removed his question once I answered it?

In this case it's a complete waste of time, without even complaining about the indelicacy that this PO has shown.

So, vv, why did you remove your last question once answered ?

As a reminder, it was a manual simplification (Maple did not succeed in doing so) of  expression

expr := 512*b^9 + (2303*a + 2304)*b^8 + (4616*a^2 + 9216*a + 4608)*b^7 + (5348*a^3 + 16128*a^2 + 16128*a + 5376)*b^6
 + (4088*a^4 + 16128*a^3 + 24192*a^2 + 16128*a + 4032)*b^5 + (1946*a^5 + 10080*a^4 + 20160*a^3 + 20160*a^2 
+ 10080*a + 2016)*b^4 + (728*a^6 + 4032*a^5 + 10080*a^4 + 13440*a^3 + 10080*a^2 + 4032*a + 672)*b^3 
+ (116*a^7 + 1008*a^6 + 3024*a^5 + 5040*a^4 + 5040*a^3 + 3024*a^2 + 1008*a + 144)*b^2 
+ (26*a^8 + 144*a^7 + 504*a^6 + 1008*a^5 + 1260*a^4 + 1008*a^3 + 504*a^2 + 144*a + 18)*b + 9*a^8 
+ 36*a^7 + 84*a^6 + 126*a^5 + 126*a^4 + 84*a^3 + 36*a^2 + 9*a + 1

in order to obtain (a+2*b+1)^9 - a*(a-b)^8 

 

1,1,2,2,2,3,3,2,2,1,2,2,2,3,3,1,1

i would like to research the ordering mechanism of this kind of series Before sorting.

How I can simplify result? For factor or using rule.

Thanks

 

Hi Maple Experts and all,

 

There is a conjecture from a book written in 1986.

This conjecture states that

"Given any four consecutive integers greater than 11, there is at least one of them that is divisible by a prime greater than 11."
 

Is anyone willing to write Maple code to test this up to a reasonable numerical limit?

See a discussion thread

https://mersenneforum.org/showthread.php?p=518300#post518300

I imagine the ifactor() command and loops.  I'm not that good at coding.

 

Regards,

Matt

can maplesim simulate a robot arm and hand catch a throwing ball and picking objects?

can maplesim simulate a balancing a robot legs?

will these simulation require complex formula to draw the robots arm and hand and maintain the joints stick together during motions?

can maplesim output the specification to autodesk for 3D print parts?

how much of a maplesim? 

i can not see the price in maple official site from Hong Kong area.

Dear there, 

Is there a possibility for tracking changes like Microsoft Office in the saved a Maple worksheet after some editings?


I think that we all encounter the same case. I mean we don't remember generally all changes after editing our codes. 

If there is no possibility for tracking changes,  what are your solutions or suggestions in order to prevent to forget? 

Hi

how can i find x in terms of y(x)

 

y(x)=integral exp(-x)/(sqrt(exp(-2 x) + a) - sqrt(a)) dx = e^x (sqrt(a + e^(-2 x)) + sqrt(a)) - log(sqrt(a + e^(-2 x)) + e^(-x)) + constant
(assuming a complex-valued logarithm)

Is it considered a bug when pdetest does not give zero for a solution given by pdsolve? 

restart;
pde := x*diff(w(x,y,z),x)+  a*z*diff(w(x,y,z),y)+b*y*diff(w(x,y,z),z)=c:
sol:=pdsolve(pde,w(x,y,z));
pdetest(sol,pde)

Gives

which is not zero.

This is the first time I've seen this happen. 

Maple 2019.1 using Physics version 362

 

 

If we have following expression

4*beta*c*lambda^2*mu^2+2*beta*c*lambda*mu^3+2*beta*c*lambda*mu^2*nu+beta*c*mu^3*nu-4*c*lambda^2*mu^2*sigma-2*c*lambda*mu^3*sigma-2*c*lambda*mu^2*nu*sigma-c*mu^3*nu*sigma+4*beta*lambda^3*sigma+4*beta*lambda^2*mu*sigma+2*beta*lambda^2*nu*sigma+2*beta*lambda*mu^2*sigma+2*beta*lambda*mu*nu*sigma+beta*mu^3*sigma+beta*mu^2*nu*sigma+4*lambda^2*mu^2*sigma+2*lambda*mu^3*sigma+2*lambda*mu^2*nu*sigma+mu^3*nu*sigma

If I use the command simplify(---,size), it gives

((2*c-2)*lambda-beta+nu*(-1+c))*mu^3+(2*(lambda*(-1+c)-(1/2)*beta))*(2*lambda+nu)*mu^2-2*beta*lambda*(2*lambda+nu)*mu-2*lambda^2*beta*(2*lambda+nu)

which can also be written if i did manually as

beta*mu^3+(2*lambda+nu)*(beta*mu^2+2*beta*lambda*mu+2*beta*lambda^2+(1-c)*(2*lambda+mu)*mu^2)

My question with all learned people is: in Maple, how i can get most simplified and short expression automaticall?

Please help me to understand the Maple.

Thanking you in anticipation.

I need to use gamma as a "free" symbol in pde that I pass to pdsolve, so that the latex comes out as \gamma OK in the solution.

in other words, the pde itself uses the symbol gamma (as it is written in the textbook and I want to keep it the same). This gamma is not the known constant gamma. Something similar to using alpha and beta or x and y. 

But gamma in a known constant in Maple and I am worried this will affect some computation inside pdsolve if I use gamma  as known number in the PDE (even though I think it should not change the result of pdsolve as there are no other numbers in the PDE input, I just wanted to be safe).

I am not able to clear gamma

unassign(gamma)  gives error since it is protected.

Is  there a way around this? Should I use wrap the name with 'gamma'  or `gamma` for example? 

Here is an example

pde := a*diff(w(x,y,z),x)+ b*diff(w(x,y,z),y)+c*diff(w(x,y,z),z)= alpha*x+beta*y+gamma*z+delta;

It is the gamma above I am worried about using in the input. What is the correct way to do this?  

Hello,

I am trying to work with the Physics package to calculate Christoffel symbols. I have just started using Maple today and am coming up against a few hurdles.

I want to change the signature of the metric from (+---) to (-+++). I am typing the following in math mode:

Setup( signature = '-+++')

However, this is returning the following error:

"Error, invalid sum/difference" with my command rewritten within a red box together with the last '+" within another red box. Can you please help me out with this?

Thank you.

 

I am completely new to maple and am stuck in the very beginning trying to use the Physics package to calculate Christoffel symbols. Suppose I have coordinates (t, x, sigma, theta). The metric g_ has coefficients that are functions of (t,x,sigma) i.e. the metric is like

g_ = a(t,x,sigma) dt^2 + b(t,x,sigma)dt dx + dx^2 + dsigma^2 + sigma^2 dtheta^2.

(Should I write dsigma^2 or (d sigma)^2?)

How do I tell maple to treat a, b as functions of (t,x,sigma)?

Thank you.

HI, 

Yesterday I replied  denitsastaicova's question while providing an attached file. 

Surprisingly, I wasn't able to save the worksheet after having executed it. The only way I found to save it was to copy-paste it's content in a new worksheet and save this latter without any execution.
Here is the file
events.mw

For info I'm working with  Standard Worksheet Interface, Maple 2015.2, Mac OS X, December 21 2015 Build ID 1097895
on Mac OS Mojave 10.14.3
If I open this file and execute it (and even if I execute only the commands from the initial restart to the three dsolve), I get this pop-up error message when trying to save it:

Does my worksheet contain some undesired character or is it a bug ?

Hello,

How can write a code for determination of Laplacian in a new form is introduced in maple code (First line).

Thank you.

FOR2
 

``

"L:=(∑)`e__i`/(`h__i`)*(∂)/(∂ `xi__i`).((∑)(∑)`e__k`/(`h__k`)((∂)/(∂ `xi__k`)`U__j`*`e__j`+`U__j`(∂)/( `xi__k`)`U__j`)):"

restart; with(VectorCalculus); with(LinearAlgebra); h__1 := VectorCalculus:-`*`(a, 1/cosh(r)); h__2 := VectorCalculus:-`*`(a, 1/cosh(r)); h__3 := VectorCalculus:-`*`(sinh(r), 1/cos(theta)); U__1 := u__r; U__2 := `u__θ`; U__3 := `u__φ`

"for i from 1 to 3 do  for j from 1 to 3 do  for k  from 1 to 3 do     if i=1 then   `h__i`:=a/(cosh(r)-cos(theta)); `U__i`:=`u__r`;`e__i`:=`e__r`:`xi__i`:=r:     else  if i=2 then  `h__i`:=a/(cosh(r)-cos(theta));`U__i`:=`u__theta`;`e__i`:=`e__theta`:`xi__i`:=theta:  else ;   `h__i`:=a/(cosh(r)-cos(theta));`U__i`:=`u__phi`;`e__i`:=`e__phi`:`xi__i`:=phi:  end if;          if  j=1 then ;  `h__j`:=a/(cosh(r)-cos(theta)); `U__j`:=`u__r`;`e__j`:=`e__r`:`xi__j`:=r:   else if  j=2 then;  `h__j`:=a/(cosh(r)-cos(theta));`U__j`:=`u__theta`;`e__j`:=`e__theta`:`xi__j`:=theta:  else ;   `h__j`:=a/(cosh(r)-cos(theta));`U__j`:=`u__phi`;`e__j`:=`e__phi`:`xi__j`:=phi:  end if;       if k=1 then   `h__k`:=a/(cosh(r)-cos(theta)); `U__k`:=`u__r`;`e__k`:=`e__r`:`xi__k`:=r:   else if i=2 then  `h__k`:=a/(cosh(r)-cos(theta));`U__k`:=`u__theta`;`e__k`:=`e__theta`:`xi__k`:=theta:  else     `h__k`:=a/(cosh(r)-cos(theta));`U__k`:=`u__phi`;`e__k`:=`e__phi`:`xi__k`:=phi:  end if;                   end ;  end ;         end ;               "

Error, unterminated loop

"for i from 1 to 3 do  for j from 1 to 3 do  for k  from 1 to 3 do    if i=1 then `h__i`:=a/(cosh(r)-cos(theta)); `U__i`:=`u__r`;`e__i`:=`e__r`:xi__i:=r:     else  if i=2 then  `h__i`:=a/(cosh(r)-cos(theta));`U__i`:=`u__theta`;`e__i`:=`e__theta`:xi__i:=theta:  else ;   `h__i`:=a/(cosh(r)-cos(theta));`U__i`:=`u__phi`;`e__i`:=`e__phi`:xi__i:=phi:  end if;       if j=1 then ;  `h__j`:=a/(cosh(r)-cos(theta)); `U__j`:=`u__r`;`e__j`:=`e__r`:xi__j:=r:   else if j=2 then;  `h__j`:=a/(cosh(r)-cos(theta));`U__j`:=`u__theta`;`e__j`:=`e__theta`:xi__j:=theta:  else ;   `h__j`:=a/(cosh(r)-cos(theta));`U__j`:=`u__phi`;`e__j`:=`e__phi`:xi__j:=phi:  end if;     if k=1 then `h__k`:=a/(cosh(r)-cos(theta)); `U__k`:=`u__r`;`e__k`:=`e__r`:xi__k:=r:   else if i=2 then  `h__k`:=a/(cosh(r)-cos(theta));`U__k`:=`u__theta`;`e__k`:=`e__theta`:xi__k:=theta:  else `h__k`:=a/(cosh(r)-cos(theta));`U__k`:=`u__phi`;`e__k`:=`e__phi`:xi__k:=phi:  end if;           end ;  end ;     end ;               "

 

i

i

(1)

j

j

(2)

``


 

Download FOR2

 

 

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