Maple Questions and Posts

These are Posts and Questions associated with the product, Maple

In feature "Procedures for two animations" posted by Kitonium appears this line, within a procedure.

T1:=(O2*~y+O1*~u)/~(y+u): T2:=(O3*~u+O2*~v)/~(u+v): T3:=(O4*~v+O3*~z)/~(v+z):

What is the meaning of "~y", for instance, and how does it differ from "y"?

I understand the conventional usage of ~ with a name in output to imply that that name is subject to an assumption.

I have been able to find nothing pertinent in the Maple Help information.  Please enlighten me.

Hi everybody.

I often regret that Maple 18 and further versions (maybe some others before ?) do not represent lengthy and complex outputs by introducing substitution expressions (i.e. %1, %2, ...) as Maple 5 or 8 did.

An exemple can be found in the Maple V release 5 programming Guide (p95, expression %1 = ...)

To be more precise I provide you the output Maple 2015 gives on the same problem treated in "Introduction to Maple, André Heck (1993) Springer Verlag" ; page 86 (no advertising here !).

The problem is about solving a polynomial system in 3 indeterminates.
One of the (set of) solutions is quite complex and looks like (I represent just the beginning of the complete solution) :

{x = %1, y = -1/8*(%1^6 + 15*%1^4 ...) / %1^4 , z = ...}
%1 := RootOf(....)  

From at least Maple 18 this same solution takes this form

{x =  RootOf(....), y = -1/8*( RootOf(....)^6 + 15* RootOf(....)^4 ...) / %1^4 , z = ...}

My question is very simple : Does it exist a way to tell Maple to act as Maple 5/8 did ?

Thanks in advance.


PS1 : I tried things like subs(RootOf(....)=freeze(RootOf(....)), sols) but it is not perfect because I dit this manually, by a copy of RootOf(....) from the output and a paste into the subs(....) input (shame on me !)


PS2 : I use to work in worksheet mode, not document mode, and I would prefer an answer adapted to the worksheet mode.

 

Download Maple2015.mw

Hi All,

When doing retart in a saved workbook get a no read access error link (see partial screen shot below). When the link is followed the message is there is no help for this error.

I am using Windows 10 64 bit and have full administrative prilvilages so I not sure what the problem is.

I have the same issue when I upload to the cloud.

In spite of message I can still do computations.

Any help in understanding this will be greatly appreciated.

Thanks,

 

Joe

 

g:= a -> int(f(x+a),x=a..2*a):
eval(g(x),x=1);
                    int(f(2 x), x = 1 .. 2)
eval(g(z),z=1);
                   int(f(x + 1), x = 1 .. 2)

eval is advertised as smart, but it's not enough!


(Related to a recent answer of Carl Love about bound variables.)

 

Edit: shorter version

g:= a -> int(sin(sin(x+a)),x=a..2*a):
evalf(eval(g(x),x=1))=evalf(eval(g(z),z=1));
                  0.1052070507 = 0.5294405453

After several attempts on this question,

Int(x*sqrt(2*x^4+3),x) with substitution u = sqrt(2)*x^2,

I don't seem to find the solution. Can you guys help me?

Hi, I am new to the Maple.

I have been trying to figure out this question:

Find the numerical (decimal) value of

f (ln (5π) + 2e5 + √ 4 + sin (4) ) 

 Here is what I wrote:

>f := ln(5*Pi)+2*e^5+sqrt(4+sin(4));
f := ln(5*Pi)+2*e^5+sqrt(4+sin(4))
>evalf(%);
4.555055775+2.*e^5

I got "4.555055775+2.*e^5" as my answer which is correct. However, I would perfer to get a decimal number like "301.381..."

Could anybody show me how?

The page ?type,piecewise shows the example

type(piecewise[](x < 1, a, b), 'piecewise');

and lines 4-8 of showstat(`print/piecewise`) deal with the case of an indexed piecewise. Yet I can find no other reference to indexed piecewise. What is it used for? When I put an index on a piecewise, nothing special seems to happen, either computationally or display-wise:

piecewise[abs](x > 0, x, -x);
piecewise[Carl](x > 0, x, -x);

The code in `print/piecewise` suggests that it serves some purpose.

system3d := a[1](a[1])+a[2]*a[4]+a[3]*a[7]-a[1](a[1])-a[2]*a[10]-a[3]*a[19], a[1]*a[2]-a[1]*a[2]+a[2]*a[5]-a[2]*a[11]+a[3]*a[8]-a[3]*a[20], a[1]*a[3]-a[1]*a[3]+a[2]*a[6]-a[2]*a[12]+a[3]*a[9]-a[3]*a[21], a[1]*a[4]-a[1]*a[4]-a[2]*a[13]-a[3]*a[22]+a[4]*a[5]+a[6]*a[7], a[2]*a[4]+a[5](a[5])+a[6]*a[8]-a[1]*a[5]-a[2]*a[14]-a[3]*a[23], a[3]*a[4]+a[5]*a[6]+a[6]*a[9]-a[1]*a[6]-a[2]*a[15]-a[3]*a[24], a[1]*a[7]+a[4]*a[8]+a[7]*a[9] = a[1]*a[7]+a[2]*a[16]+a[3]*a[25], a[2]*a[7]+a[5]*a[8]+a[8]*a[9] = a[1]*a[8]+a[2]*a[17]+a[3]*a[26], a[3]*a[7]+a[6]*a[8]+a[9](a[9]) = a[1]*a[9]+a[2]*a[18]+a[3]*a[27];
print(`output redirected...`); # input placeholder
a[2] a[4] - a[2] a[10] + a[3] a[7] - a[3] a[19],

a[2] a[5] - a[2] a[11] + a[3] a[8] - a[3] a[20],

a[2] a[6] - a[2] a[12] + a[3] a[9] - a[3] a[21],

-a[2] a[13] - a[3] a[22] + a[4] a[5] + a[6] a[7], a[2] a[4]

+ a[5](a[5]) + a[6] a[8] - a[1] a[5] - a[2] a[14] - a[3] a[23],
-a[1] a[6] - a[2] a[15] + a[3] a[4] - a[3] a[24] + a[5] a[6]

+ a[6] a[9], a[1] a[7] + a[4] a[8] + a[7] a[9] = a[1] a[7]

+ a[2] a[16] + a[3] a[25], a[2] a[7] + a[5] a[8] + a[8] a[9] =

a[1] a[8] + a[2] a[17] + a[3] a[26], a[3] a[7] + a[6] a[8]

+ a[9](a[9]) = a[1] a[9] + a[2] a[18] + a[3] a[27]

solve({system3d}, {a[1]*a[2], a[1]*a[3], a[1]*a[4], a[1]*a[5], a[1]*a[6], a[1]*a[7], a[1]*a[8], a[1]*a[9], a[2]*a[4], a[2]*a[5], a[2]*a[6], a[2]*a[7], a[2]*a[10], a[2]*a[11], a[2]*a[12], a[2]*a[13], a[2]*a[14], a[2]*a[15], a[2]*a[16], a[2]*a[17], a[2]*a[18], a[3]*a[4], a[3]*a[7], a[3]*a[8], a[3]*a[9], a[3]*a[19], a[3]*a[20], a[3]*a[21], a[3]*a[22], a[3]*a[23], a[3]*a[24], a[3]*a[25], a[3]*a[26], a[3]*a[27], a[4]*a[5], a[4]*a[8], a[5]*a[6], a[5]*a[8], a[6]*a[7], a[6]*a[8], a[6]*a[9], a[7]*a[9], a[8]*a[9], a[1](a[1]), a[5](a[5]), a[9](a[9])});
%;
Warning, solving for expressions other than names or functions is not recommended.
{a[1] a[2] = a[1] a[2], a[1] a[3] = a[1] a[3],

a[1] a[4] = a[1] a[4], a[1] a[5] = a[2] a[10] - a[3] a[7]

+ a[3] a[19] + a[5](a[5]) + a[6] a[8] - a[2] a[14]

- a[3] a[23], a[1] a[6] = -a[2] a[15] + a[3] a[4] - a[3] a[24]

+ a[5] a[6] + a[6] a[9], a[1] a[7] = a[1] a[7], a[1] a[8] = a[

2] a[7] - a[2] a[17] - a[3] a[26] + a[5] a[8] + a[8] a[9], a[1]

a[9] = a[3] a[7] + a[6] a[8] + a[9](a[9]) - a[2] a[18]

- a[3] a[27], a[2] a[4] = a[2] a[10] - a[3] a[7] + a[3] a[19],

a[2] a[5] = a[2] a[11] - a[3] a[8] + a[3] a[20],

a[2] a[6] = a[2] a[12] - a[3] a[9] + a[3] a[21],

a[2] a[7] = a[2] a[7], a[2] a[10] = a[2] a[10],

a[2] a[11] = a[2] a[11], a[2] a[12] = a[2] a[12],

a[2] a[13] = -a[3] a[22] + a[4] a[5] + a[6] a[7],

a[2] a[14] = a[2] a[14], a[2] a[15] = a[2] a[15],

a[2] a[16] = -a[3] a[25] + a[4] a[8] + a[7] a[9],

a[2] a[17] = a[2] a[17], a[2] a[18] = a[2] a[18],

a[3] a[4] = a[3] a[4], a[3] a[7] = a[3] a[7],

a[3] a[8] = a[3] a[8], a[3] a[9] = a[3] a[9],

a[3] a[19] = a[3] a[19], a[3] a[20] = a[3] a[20],

a[3] a[21] = a[3] a[21], a[3] a[22] = a[3] a[22],

a[3] a[23] = a[3] a[23], a[3] a[24] = a[3] a[24],

a[3] a[25] = a[3] a[25], a[3] a[26] = a[3] a[26],

a[3] a[27] = a[3] a[27], a[4] a[5] = a[4] a[5],

a[4] a[8] = a[4] a[8], a[5] a[6] = a[5] a[6],

a[5] a[8] = a[5] a[8], a[6] a[7] = a[6] a[7],

a[6] a[8] = a[6] a[8], a[6] a[9] = a[6] a[9],

a[7] a[9] = a[7] a[9], a[8] a[9] = a[8] a[9],

a[1](a[1]) = a[1](a[1]), a[5](a[5]) = a[5](a[5]),

a[9](a[9]) = a[9](a[9])}

 

 

 

the program runs however the warning message pops ...what can i do to eliminate the problem??? 

In Maple V, Release 4 (1996):

 

T:=table():
i:=1:N:=5000;

for i from i to N  
do
   T[i]:=T[i+1]:
   T[i+1]:=1;
   eval(T[1]);
od:
print(i);

for i from i to N  
do
   T[i]:=T[i+1]:
   T[i+1]:=1;
   eval(T[1]);
od:
print(i);

I receive this output:

N := 5000
Error, too many levels of recursion
3607
5001

Can You explain this occurence, as well as the following one:

In Maple V, Release 4 (1996):

 

T:=table():
i:=1:N:=5000;

for i from i to N  
do
  T[i]:=T[i+1]:
  eval(T[1]);
od:
print(i);
 
for i from i to N  
do
  T[i]:=T[i+1]:
  eval(T[1]);
od:
print(i);;

gives:

N := 5000
Error, too many levels of recursion
3607
Error, too many levels of recursion
3607

How does one control allowance for recursion depth?

Hi,

 

I am having trouble getting a pattern match to the Heaviside function.

patmatch(Heaviside(x), Heaviside(a::algebraic))

returns "false" whereas I would expect it to return true.

On the other hand:

patmatch(Heaviside(x), Heaviside(x::algebraic))

returns true.

 

What am I missing?

 

Regards.

 

HI,

Can anyone suggest the tutorial or good examples for parallel computing in maple.

Thanks in advance.

how to use python to call maple and scroll up or down scrollbar

Hi everybody, 

 

Could somebody just explain me why commands L[1..5] and L[3..6] below do not seem to return "the same type of thing" ?

 

L := Array(1..10, [$(1..10)]);

L := Array(1..10, {(1) = 1, (2) = 2, (3) = 3, (4) = 4, (5) = 5, (6) = 6, (7) = 7, (8) = 8, (9) = 9, (10) = 10})

(1)

L[1..5];
whattype(%);

Array([1, 2, 3, 4, 5])

 

Array

(2)

L[3..6];
whattype(%);

Array(3 .. 6, {3 = 3, 4 = 4, 5 = 5, 6 = 6}, datatype = anything, storage = rectangular, order = Fortran_order)

 

Array

(3)

 


Thank you for your attention


Download array.mw

Hey,

I want to solve this equation and looking at the plot there are at least 3 solutions. I want the greatest/smallest negative solution. Unfortunately using solve with assumptions produces no results and solve without assumptions only finds two solutions.

Can you please help me?

#select greatest negative value from solution

restart:

expr:= ax*cos(lambda)+ay*sin(lambda)-(a+b*lambda)

ax*cos(lambda)+ay*sin(lambda)-b*lambda-a

(1)

ax:=1:ay:=2:a:=0.5:b:=0.25: #examplanatory values

plot(expr)

 

 

assume(-2*Pi<lambda,lambda<0): #does not work

 

sol_lambda:=[solve(expr=0,lambda, useassumptions)];# returns empty list even though without assumption one solution is found

Warning, solutions may have been lost

 

[]

(2)

sol_lambda:=[solve(expr=0,lambda)]; #returns only two solutions even though looking at the plot 3 are there

Warning, solve may be ignoring assumptions on the input variables.

 

Warning, solutions may have been lost

 

[2.190357220, -.2688724573]

(3)

sol_l_v:=evalb~(sol_lambda<~0); #dirty workaraound

[false, true]

(4)

sol_l_add:=[ListTools:-SearchAll(true,sol_l_v)] ; #this seems overly complicated

 

[2]

(5)

lambda:=sol_lambda[sol_l_add[-1]];  #to select the last entry

 

-.2688724573

(6)

expr; #test

 

0.

(7)

 


Download select_solution.mw

Thanks!

Honigmelone

hi

how i can plot 4 curve in one graph in maple??

this data is given in excel format as below

thanks

16.3.xlsx

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