## How to obtain a function that is defined as the in...

I have a function g(x,t), which is the numerical result of a PDE.

How to calculate the function f (t), defined by:

f:=t->int(g(x,t),x=a..b)

I tried to calculate that way, but that did not work.

Thanks for the help.

## Decrypt message...

f(a)(x) = a*x mod 256  for all x in Z[256]

## problem in loop-for...

how can write this loop that has written in matlab to maple??
i=1;
for e=T1P1:0.0399:T1P;
E(i)=e;
gama1(i,:)=a-atan(e/Rb1);
i=i+1;
end

## MAPLESOFT TRIAL...

HELLO

I AM A STUDENT AND WAS LOOKING FOR USING MAPLE2018.

I REQUESTED FOR A MAPLE EVALUATION. MY QUESTIONS ARE:

FOR HOW LONG CAN I USE THIS EVALUATION VERSION?

SECONDLY, WHAT SOFTWARE FACILITIES I WOULD NOT GET WITH THIS EVALUATION VERSION? WHAT ARE THE DIFFERENCES BETWEEN THE PRICED ENTERPRISE VERSION AND MAPLESOFT EVALUATION VERSION?

THIRDLY, WHAT ARE THE DIFFERENCES BETWEEN MAPLESOFT STUDENT VERSION AND THE ULTIMATE PRICED ENTERPRISED VERSION?

PLEASE REVERT BACK TO ME AT THE EARLIEST.

## Remove Assumptions for Code Generation...

Hi,

this has been asked before but none of the other answers worked for me. I want to generate code from expressions that were simplified using some assumptions. I the assumptions remain on the variables Maple replaces variable names wich I don't understand.

Here is my script where I tried to remove the assumptions based on the answers of previous questions. Unfortunately, even though assumptions are removed in the end, Code generation still replaces the variables.

Here is my minimal exaple Code:

 >
 > restart:
 >
 > # test removing assumptions
 > funa:=x+y
 (1)
 > Maple_proc := codegen[makeproc](funa,(ListTools[Flatten]([eval(alist,1)])));
 (2)
 > # make some assumptions
 > assume(x,real);assume(y,real);
 > x,y
 (3)
 > #place variables in a list
 > alist:=[x,y];
 (4)
 > # make cool interferences with assumptions...
 > # clear assumptions
 > # try 1 from https://www.mapleprimes.com/questions/207601-Remove-Assumptions-
 > nms:=convert(indets(alist,name),list); nmsS:=convert~(nms,string); L:=StringTools:-Substitute~(nmsS,"~",""); #Removing "~" L1:=parse~(L); S:=nms=~L1; Expr:=subs(S,expr);
 (5)
 > hasassumptions(x)
 (6)
 > # try 2
 > nops(alist)
 (7)
 > for i from 1 to nops(alist) do parse(cat(StringTools[Substitute]~(alist[i],"~",""),":='",StringTools[Substitute]~(alist[i],"~",""),"'")); end do;
 (8)
 > # check if assumtions are there
 > hasassumptions(x)
 (9)
 > #try 3 https://www.mapleprimes.com/questions/39555-Unassume
 > for u in alist do `property/object`[u]:=evaln(`property/object`[u]); `property/OrigName`[u]:=evaln(`property/OrigName`[u]); end do;
 (10)
 > hasassumptions(x)
 (11)
 > hasassumptions(y)
 (12)
 > alist
 (13)
 > funb:=x+y
 (14)
 > Maple_proc := codegen[makeproc](funb,(ListTools[Flatten]([eval(alist,1)])));
 (15)
 > Maple_proc := codegen[makeproc](funa,(ListTools[Flatten]([eval(alist,1)])));
 (16)
 >
 > CodeGeneration[C](Maple_proc, optimize, declare=[x::float,y::float], defaulttype=float, deducetypes=false, coercetypes=false, output="fun.c");
 >
 >
 >
 >
 >
 >
 >
 >
 >

## "how can I get the order of convergence of an iter...

`please I need the code to calculate the convergence order of a multipoint iterative method to solve nonlinear equation systems.`

`my email is: yjmsigma@gmail.com`

## how to change color of just the axis tick labels f...

is there a way to change the color of just the labels on the axis ticks only?

I wanted to do this for DEplot, but I started with normal plot since it is easier. I could change the colors of the axis, but this changes not only the tick labels but the whole axis itself:

```restart;
plot(sin(x),x=-Pi..Pi,axis=[tickmarks=[color=red]], color=blue);

```

So the axis itself changed color as well. It is OK for the ticks as well as the ticks labels (the numbers of the ticks). But prefer the axis itself not to be red.

Once there is a way to do the above, I wanted to apply to DEtools:-DEplot. Why? Becuase it is hard to read the Axis tick labels on DEplot. I thought that changing the color of the tick labels will it easy. But DEtools:-DEplot does not even accept axis command:

```ode:= diff(y(x),x)=2*x:
DEtools:-DEplot(ode,y(x),x = -2 .. 2,y = -2 .. 2, [[0.1,0]],
labels=["",""],
linecolour = red,
color = blue,
'arrows' = 'medium',
axesfont=['Times', 'bold', 12]
);
```

You can see it is hard to read the axis tick labels above, as arrows go over some of them,. If I make them say RED, I think it will make it more clear.

Now when adding the axis options, it gives error

```DEtools:-DEplot(ode,y(x),x = -2 .. 2,y = -2 .. 2, [[0.1,0]],
linecolour = red,
color = blue,
arrows = MEDIUM,
axesfont=['Times', 'bold', 10],
axis=[tickmarks=[color=red]]
);
```

Error is generated, axis is not supported command.

Any idea how to make tick labels red for DEtools:-DEplot? It will be OK if I can get both the axis and the ticks RED, at least it will be better than it is now.

One workaround way I currently use is this:

```ode:= diff(y(x),x)=2*x:
p1:=DEtools:-DEplot(ode,y(x),x = -2 .. 2,y = -2 .. 2, [[0.1,0]],
labels=["",""],
linecolour = red,
color = blue,
'arrows' = 'medium'
);
p2:=plot(0,x=-2..2,y=-2..2,axis=[tickmarks=[color=red]]);
plots:-display([p2,p1]);
```

But this seems like a hack to me. There should be a way to directly set tickmarks color in DEplot?

## Help me extracting the data from the Maple figure....

Help me extracting the data from the Maple figure. I was used the 'implicitplod3D' command to draw the figure.  I want to save the parameters of sigma, A  and f0 in Exce

 > af_eq := (3*alpha[2](t[1], t[2])*A^3*(1/8)-A*sigma)^2+(1/4)*alpha[1](t[1], t[2])^2*A^2 = (1/4)*f0^2
 (1)
 > with(plots, implicitplot,implicitplot3d):
 > alpha[1]:=0.1;alpha[2]:=0.1299;
 (2)
 > ##3D
 > implicitplot3d(af_eq, sigma = -1.5 .. 1.5,f0 =0..0.5, A = 0 .. 5,numpoints = 20000,style=surfacecontour,contours = 15);
 >
 >

l format. then, I can use the data draw a picture in other software. Many thanks.

## How to solve numerically a PDE system with IBCs th...

I have a PDE system, which has IBCs that involve the unknown functions of the system. This system describes the mechanical evolution of a material volume, where material boundaries vary (it is an open physical system with mass addition). This problem has an analytical solution, but I am looking for a numerical solution. I do not know how to solve this (actually, I do not know if that's possible). I made a few attempts and I did not succeed.

On the last attempt, pdsolve returned the following error message: "Error, (in pdsolve/numeric/process_PDEs) PDEs can only contain dependent variables with direct dependence on the independent variables of the problem, got {u(H(t), t)}".

PDE_SYS.mw  (I re-uploaded the file because there was an error)

Well, I'd like some help on that. Thank you.

## Christoffel symbols and Ricci tensor and scalar....

I am a little bit clueless here, about how to use maple to calculate Christoffel symbol and Ricci tensor and scalar?

I read the help, but it got me confused; I have the metric ds^2 = du*dv+F(y,z)du^2+dy^2+dz^2

It's not Minkowski nor Cartesian, so how to use maple to calculate these symbols?

I am sure it's easy, but I didn't quite follow maple's instructions.

## Plotting the free space diagram (Fréchet distance)...

Hello!

I am interested in plot the so-called "free space diagram", please see https://en.wikipedia.org/wiki/Fr%C3%A9chet_distance for a formal definition. Essentially, given two curves (i.e., two polygonal from [0,1] to the plane) the "free space" is the points (s,t) in the square [0,1]x[0,1] such that the distance from P(s) to Q(t) (if P and Q are the parametrizations of the curves) is less or equal than a prefixed epsilon>0. An image can be the following (the free space is, in the image, the area not colored in black):

Thanks!

## Variation in cosmology...

Hello guys

I have a simple but crucial question about variation, especially in cosmology and gravity. suppose we have the action such as

S=int(sqrt(-g)*F(R,RµναβRµναβ),d^4x) where g is determinant metric gµν and d^4x is space in 4D and F is an arbitrary function of R (Ricci scalar) and scalar which created by Riemann tensor. How we can define this action in the maple 18 and take variation with respect to the metric.

thanks

## how to write a conditinal loop...

how to write in mape
if x not real set x =b

## what are the rules for naming constants of integra...

Is there a place to read about rules for naming constants of integrations for solution of ODE so that Maple odetest will not have problem verifying solution of an ODE?

It seems Maple does not like some constant names. If I use C or C1 or C[1] or A etc... odetest does not give back zero, even thought the solution is exactly the same as Maple's, except Maple uses _C1.

I read one is not supposed to use _ constants in own code, since these are reserved for Maple.

So what is one supposed to use? Here is an example

```restart;
ode:=2*sqrt(x)*diff(y(x),x)=sqrt(1-y(x)^2):
my_sol:=y(x)=sin(sqrt(x)+(1/2)*C1);
```

Compare to Maple own solution

`maple_sol:=dsolve(ode,y(x));`

You can see, there is no difference, except the name of the constant.  Yet, Maple does not odetest my solution

```odetest(my_sol,ode);
```

I tried naming my constant to C, C[1], A, Z, etc.. I got tired trying. Only when I use _C1 does Maple give zero for odetest.

What is so special about _C1?  And if one can't use _ symbols as Maple says, what is one to to do?

Maple 2018.1, Physics version `2018, July 21, 4:16 hours, version in the MapleCloud: 78, version installed in this computer: 78`

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