What kind of solution is it (see (3))? Why is there no solution when I put the initial condition v(0)=C1? Secondly, eq. (2) can be reduced to a first-order differential equation?

Download CD_ode.mw

File:

PCA.mw

I am a student in the middle of a projekt, where math is an essential part of the task. I have done a lot of work in a maple document, but this document suddenly became corrupted. I've tried restarting and loading backups and f ollowed Can I repair a corrupted Maple document/worksheet file? (maplesoft.com) but the solutions didn't work on my document.

Also tried the DeleteBadCharacters() proccess, but i get the error "Error, (in XMLTools:-ParseString) Element type "Equation" must be followed by either attribute specifications, ">" or "/>"."

Is there a way to fix this issue, and prevent the same issue occuring in the future? 

Thanks in advance!

This is a training example for finding all solutions to a system of equations. If you look at the graph, you can count 36 solutions, but I managed to find 20 relatively good approximations. No attempts to get more solutions, which are also visible as intersections of graphs, did not lead to success. Therefore, there is a suspicion that there are only 20 solutions.
Is it so?

 restart: with(plots):
 a:=8.:
 f1 := x1^4-1.999*x1^2*x2^2+x2^4-1; 
 f2 := tan(x1+x2)-x2*sin(x1);
 implicitplot([f1, f2], x1 = -a .. a, x2 = -a .. a, numpoints = 25000, scaling = constrained,  color = [red, blue], thickness = 1);

   1, (3.192246883291975), (-3.0395187374365404)
   2, (3.0952031367176476), (-3.2447717313041897)
   3, (0.5881900748267959), (-1.160066226905079)
   4, (-0.936866718243322), (-1.3700058362814254)
   5, (-2.555853694651265), (-2.7399958564861953)
  6, (-3.2556241416421168), (-3.3964651254113774)
   7, (-3.583319843955091), (-3.7077839724189228)
   8, (-5.364827188794712), (-5.401998918608201)
   9, (-5.398295356665546), (-5.360818510223991)
  10, (-3.769206506106412), (-3.6477855329362683)
  11,(-1.3978806247566642), (-0.9772190664843745)
   12, (-1.192159295544978),(0.6492335177657542)
   13, (-3.0867255059416623),(2.927375855548188)
    14, (-3.18519036357835), (3.329801919022179)
   15, (2.0108268901120754), (2.243492422396739)
   16, (3.1133812329649766), (3.261937603184373)
   17, (4.0265558604742715), (4.130826167761226)
    18, (4.124539552922121), (4.019977762680433)
    19, (3.172338340844501), (3.018365965761908)
   20, (2.1945695320368097), (1.9558412553082192)

PROBLEM-IP.mw

Download PROBLEM-IP.mw

Hi !

I want to create a notation for a function, let's say :

f:=(x,y,z)->something

such that when I ask for

f(x,y,z) 

Maple returns

f^x,y(z) or anyother "nicer view" of that expression.

This is (I think) a similar action of replacing BesselJ(n,x) by J_n(x).

Many thanks for your answers !

Kevin

This is a follow-up to a previous question I asked that was answered with code that used "%.". From the documentation I can see that % is a nullary operator that gives us the value of "the last expression", which I think means the last result of an evaluated expression.

In my previous question, I wanted to be able to display for example, a constant times a matrix, without the product being evaluated.

For example, given A:=<1,2;3,4>:, we need to use Maple Input, and then we can write c__1.A and the output will be an expression that has c__1 then the dot product symbol and then the matrix A written out.

My question is simply: what exactly is "%."?

Hi all, 

I am working with the physics package and I want to know if there is a difference between Physics:-CompactDisplay and PDEtools:-declare ?

As well as the difference between Physics:-Simplify and simplify.

For both cases, can they be used as the same ? Are they incompatible in some case?

Thanks !

Kevin

I would like to display an expression that is a matrix, the dot operator, and another matrix. That is, I want to display a multiplication of matrices, without the multiplication being evaluated.

Something like

<1,2;3,4> '.' <6,7,8,9>

Is this possible?

Here is some context around why I want to do this. Perhaps the main reason I use Maple is for the symbolic math capabilities using 2d math input. I want to create worksheets that look like what I would write on paper. 

For example, let's say I have a matrix that is defined by <I, F;0,0>, where each of elements is actually another matrix. I want to multiply this matrix by its transpose, which would be something like <I, 0^T; F^T, 0^T>.

I would like to display <I, 0^T; F^T, 0^T> .  <I, F;0,0>.

Hello guys
I created a document recently and, the next day, when I tried to open it, I received the following message:

        Recover corrupted file and save as

Does anyone know how to recover a corrupted file?
Regards,
Oliveira

Dear all

I would like to expand x^m using JacobiP  ( jacobi polynomials), with the two parameter alpha  and alpha +2, I have a result in my book using alpha and alpha+1 but i would like to get a similar result using alpha and alpha+2 

Inverse_formula_jacobi_polynomials.mw

Thank you 

I have a system of ODE's which are solved numerically (with rkf45) to get function values over time. And i have datapoints for these functions, and would like to compare and calculate the error/deviation between model and data. I can't find a command / mechanism that does this.

Is it possible?

I know maple help has exercies where you can learn from. I was, however, wondering if there is a standard place where people upload their specialized worksheets and maple documents they have used for research once they make it public.

Suppose I have a excel file with say 20 columns of data with equal number of rows of data. All numeric data

How to read each column data to a seperate variable

Or 

The entire data into a matrix 

The graph we draw in the graph theory package appear to be vectorial. So the export pdf is also clear. 

with(GraphTheory):
DrawGraph(PathGraph(2), stylesheet=[vertexborder=false,
vertexpadding=5,edgecolor = blue,vertexcolor=black,edgethickness=2],size=[250,250])

draw1.pdf

We know that DrawGraph only offers straight forms for drawn edges.  Sometimes we need to draw graphs with curves.  But when I try to use maple, I find that the vertices (by pointplot) are blurred after zooming in (or even without zooming out).

with(plottools):    
with(plots):
Bezier:=proc(x0,y0,x1,y1,x2,y2,x3,y3)
local f,g,c,l1,l2,l3,p0,p1,p2,p3;
f:=t->x0*(1-t)^3+3*x1*t*(1-t)^2+3*x2*t^2*(1-t)+x3*t^3:
g:=t->y0*(1-t)^3+3*y1*t*(1-t)^2+3*y2*t^2*(1-t)+y3*t^3:
c:=plot([f(t),g(t),t=0..1],thickness=2,scaling=constrained, color=blue,axes=none):
p0:=pointplot([x0,y0],symbol= solidcircle,symbolsize = 50,color=black):
p1:=pointplot([x3,y3],symbol= solidcircle,symbolsize = 50,color=black):
display(c,p0,p1,size=[300,300]);
end:

x0:=0:   y0:=0:
x1:=-0.2:  y1:=0.2:
x2:=0.5:  y2:=0.2:
x3:=0.3:  y3:=0:
p:=Bezier(x0,y0,x1,y1,x2,y2,x3,y3)

 draw2.pdf 

How to make these vertices vectorially drawn (like DrawGraph)？

If I have a set S:= [a,b,c],

I want the loop to give me: [[a,b,c],[a+b,c],[a+c,b],[a,b+c],[a+b+c]]