Background:
I would like to achieve textbook style formatting of integrals in Maple output. I am aware that interpreting a dx in an integral as a "differential" is controversial. The way Maple displays the integration variable in italic and the d in roman makes sense and avoids confusion with interpretations that are no longer needed.
However, what I want to avoid is mixing dx and dx in the same document.

Can Maple be set by default that the d in the dx of an integral becomes italic?

If this is not possible and because this question comes from habits in physics: Would a display option in the physics package be possible?

Download Differential_format_in_integrals.mw

Execute the following codes in Maple input (1-D math) in the Standard interface. 

(cat("A".."C"),cat("d".."f"))||'$"G".."I",$"j".."l"'; 

Then an error occurred. But if one copy them into 2-D math (instead of Convert To>2-D Math Input) and execute them directly, everything goes without any error messages.

It says that mixed 1-D and 2-D math inside one command is not supported and not recommended stylistically. However, I just want to understand the reason why an error is raised here. 

Download unexpectedConcatenation.mws

Hello everyone,

I am having trouble with this a system of 12 differential equations with the respective 12 initial conditions. I try to usen dsolve with the "numeric" parameter but it stays "evaluating" forever. I tried a system of 10 equation and I got the correct answer, although the program stayed calculating for several minutes (more or less 5 minutes). Is the size of this system too much to handle for the program? 

This is the system of differential equations (sys) and the initial conditions (ics) that I am trying to solve:

maple_primes_question.mw

Download maple_primes_question.mw

What am I doing wrong? or is it that the program cannot handle such a large system? In that case, that would be dissappointing since I have to solve a similar system but with up to 22 differential equations and initial conditions so I am stuck...

Anyway, thank you very much for any guidance, and happy new year.

 A:= <x1,y1,z1>:  B:= <x2,y2,z2>:  P :=<x3, y3, z3>:  H:=A+t*(B-A):  solve( (P-H)^+ . (B-A), t ):  'H'=eval(H, t=`%` );

Error, invalid powe, rhow to overcome this mistake ? Thank you.
Typesetting:-mambiguous( AAssign (x1commay1commaz1)colon  BAssign 

  (x2commay2commaz2)colon  P Assign(x3comma y3comma z3)colon  H

  AssignA + tast(Buminus0A)colon  solveApplyFunction( 

  Typesetting:-mambiguous((Puminus0H)circ + , 

  Typesetting:-merror("invalid power")) period (Buminus0A)comma t

   )colon  (H)equalsevalApplyFunction(Hcomma tequals% )semi)

Simple question I cannot remember the solution of.

When I import "executable maple input" from a file, the content is imported as a string and therefore have quotation marks around the code if saved in a variable. It therefore wont execute.

How do you defeat quotation marks around  executable maple code with a command in order to execute the code ?

hello dear maple, in the following code (code attached at the bottom )

I'm curious to know if it's possible to show the product of two matrices  in an unevaluated form, so for instance something like this instead of this 

UnEval_Mat.mw

Thanks in advance

hello maple world, in the following code (code attached at the bottom) i wish to select the terms which have the term so i used the "select" command for this task

but as u can see from the results it also selects other terms which is wrong. so what is the mistake here

thanks in advance

Physic_select.mw

Hi everyone,

I have been trying to solve a system of 8 differential equations (1st order) with 8 different initial conditions. The system in question is the following.

sys:={

diff(a[0](t), t) - diff(a[1](t), t) + diff(a[2](t), t) - diff(a[3](t), t) = 0,

diff(b[0](t), t) + diff(b[1](t), t) + diff(b[2](t), t) + diff(b[3](t), t) = 0,

diff(a[0](t), t) + diff(a[1](t), t) + diff(a[2](t), t) + diff(a[3](t), t) - diff(b[0](t), t) + diff(b[1](t), t) - diff(b[2](t), t) + diff(b[3](t), t) = 0,

diff(a[1](t), t) + 4*diff(a[2](t), t) + 9*diff(a[3](t), t) - 3*diff(b[1](t), t) + 12*diff(b[2](t), t) - 27*diff(b[3](t), t) = 0,

diff(a[0](t), t) - diff(a[1](t), t)/2 - diff(a[2](t), t)/2 - 16*a[2](t) + diff(a[3](t), t) + 48*a[3](t) = 0,

diff(a[0](t), t) + diff(a[1](t), t)/2 - diff(a[2](t), t)/2 - 16*a[2](t) - diff(a[3](t), t) - 48*a[3](t) = 0,

diff(b[0](t), t) - diff(b[1](t), t)/2 - diff(b[2](t), t)/2 - 48*b[2](t) + diff(b[3](t), t) + 144*b[3](t) = 0,

diff(b[0](t), t) - diff(b[1](t), t)/2 - diff(b[2](t), t)/2 - 48*b[2](t) + diff(b[3](t), t) + 144*b[3](t) = 0}

and the initial conditions are

ics:={a[0](0) = 1/8, a[1](0) = 1/4, a[2](0) = 1/4, a[3](0) = 1/8, b[0](0) = 23/24, b[1](0) = 1/12, b[2](0) = -1/12, b[3](0) = 1/24}

When I run 

sols := dsolve(sys union ics, numeric)

I get the error message

Error, (in DEtools/convertsys) ODE system is insufficient to determine values for all dependent variables in the system

What is happening?

Thanks for the help.

Hey guys. i recently faced a problem where i needed to substitute the "physics's overloaded product operator" , namely with normal matrice product (`.`), so maple can do the matrice product calculation after my non-commutative physics operator(yellow symbols in the following code) has been replaced with real matrices (for instance, this substitution:)

now in order to substitute  with `.` I have utilized the maple `use` command. but the problem is, it doesn't do the substitution when I utilized `use` command as follows (code file is attached at the bottom) :

so what's the mistake here?

thanks in advance

Physic_subs.mw

Let's say we have a velocity vector v := c _i + d _j, where _i and _j are the i hat and j hat Cartesian basis vectors as present in the Physics[Vectors] package.

When we integrate this velocity vector relative to t, the result in maple is the position vector (c _i + d _j)t.

I guess that is correct.

My question is: is there am in-built way to specify an initial position vector for the integration? Ie, can I specify constants in the integration?

Right now I am just doing 

s0 := sx _i + sy _j

s:= int(v, t) + s0

I've been trying to figure out what i_  means in Maple. In what follows is some experimentation and then my questions.

My question is: is the symbol _i somehow special by default? Where can I find it in the documentation?

Note the second-to-last line in the Maple document pasted above: "Doesn't work as expected". The difference between this line and the next one is simply the presence of a := instead of an =. The assignment makes the vector notation differ. Is this difference a bug or some feature I am unaware of?

Here is yet another behavior that seems kinda weird to me. Given the function f defined above, D(f) gives us the expected result but D(f(x)) does not. Yet, int(f) gives an error, and we have to use int(f(x)). 

EDIT: a little more research indicates there is a difference between the D operator and the function diff. 

Download PhysicsVectors.mw

Reading another question today I discovered that I can use syntax like

a := 2 _i + 3 _j

b:= _i - _j

a+b  

Maple computes the sum by vector component. This is very useful, and it prompted me to start reading the Multivariate Calculus Study Guide. I am still going through it but haven't seen this particular notation yet. When I check the type of a above I get a result that sort of looks like `+` but actually it seems to be tilted to the right (so I guess it is italicized and represents some symbol).

What is this type?

I don't find much searching online, and I did see this page that says 

"Any symbol beginning with an underscore (_) is effectively reserved for use only by library code. It is not available to users. Failure to observe this rule can lead to unexpected results."

Edit: After a bit more looking, looks like my example code is using notation available from the Physics package, which I am now reading a bit about (but it is not clear to my why this package is used since I am not importing it explicitly).

I noticed something that seems to be new to my usage of Maple.

As I am typing in an expression in a Maple Worksheet (Document Mode), it seems Maple goes into "Evaluating" for a split second on every new keystroke.

For context, I have my own worksheet open and also the Maple Study Guide open for Multivariate Calculus. But just now I closed it and restarted Maple. A brand new worksheet has this same behavior. 

Did I just miss this before or is it normal for Maple to show "Evaluating" for a split second on every keystroke (instead of just "Ready")?

I just wrote up a bug report (aka "Software Change Request") but got a "We are currently experiencing technical difficulties" error so the report is not being sent.

I will just post here about the bug in case anyone knows what it is.

I am going through the Multivariate Calculus Study Guide. I went to section 1.1, and was going through the examples. At the end of an example is a link "Next Example", but when I click this I get an error and have to go back to section 1.1 Table of Contents. Kind of annoying. Also, I notice that Maple simply crashes seemingly randomly when going through this study guide. Very annoying.

Here is a screenshot of the write-up to the bug report service that isn't working, for the record

I was wondering if this is something wrong with my Maple installation or if other people experience it too.

I was just trying to follow along the Multivariate Calculus Study Guide.

There is an example where we are supposed to plot a "rooted vector". Basically, a vector where the tail is not at the origin.

The commands seemed pretty straightforward but are not generating the expected results. Here is a worksheet with the commands in question

Well wouldn't ya know? I am finally able to execute a worksheet in this question box. As you can see there is no vector being displayed. Now, after playing around with the values a bit, it seems that the root that I chose, [-2,1], seems to be the only one that won't work. In particular, the value 1 there seems to be problematic. If I use any other value (including for example 0.9999999), the vector seems to be drawn correctly. 

Why doesn't it work for the original parameters I chose?

Download PlotRootedVector.mw