## Using numerically obtained functions in formulatio...

Hi I am trying to combine a previous, numerically obtained result in a subsequent calculation: outline: suppose i have a given function, f(x), and i wish to construct the following boundary value problem: y''(x)=f(x), y(0)=1, y(1)=2 the known function f(x) is a result of another calculation, which i have obtained numerically. (f(x)=proc(x)...end proc, or something to that affect). code: -------------------------------------------- > restart; > sys := {diff(y(x), x) = x, y(0) = 1}; / d \ { --- y(x) = x, y(0) = 1 }

## Create Inert Form of a Function...

How can I create the inert form of the following function: dm:=z->diff(z,t)+v[c]*d_[c](z); Note d_ is the new indicial differential operator available in physics package of Maple 11. Its inert form is %d_. What I need is that when I write, dm(rho), maple does not expand it into two terms using the above function, but displays the compact form dm(rho). I want to see the expanded form, only when needed, not at every step where dm is used. So at other steps, I just want to see dm(rho), without evaluation. Thanks, Pawan Takhar

## plot option axesfont...

In the example below, the plot option axesfont affects both axes in Maple 10.06, but in Maple 11.01 it affects only the vertical axis. Is this a feature, or a bug? If it’s a feature, how can I change the font of the horizontal axis tickmarks?

restart;
dates := [0 = "21/8/00", 140 = "8/1/01", 536 = "8/2/02", 885 = "23/1/03", 1267 = "9/2/04", 1628 = "4/2/05", 2004 = "15/2/06", 2200 = "30/8/06", 2479 = "5/6/07", 2531 = "27/7/07"];
xy := [[0, 2.5], [140, 2.2], [536, 2.6], [885, 2.5], [1267, 3.3], [1628, 3.1], [2004, 5.0], [2200, 3.0], [2479, 5.9], [2531, 4.3]];
plots[pointplot](xy,symbol=circle,tickmarks=[dates,default],axesfont=[TIMES,ROMAN,8]);

## Fortran 90 codegeneration in Maple...

This question was already raised before. Does Maple 11 "fortran" command generates code which is compatible with Fortran 90 (or 95)? I have a problem in several respects, especially in the syntax of "continuation" lines. How can I generate Fortran 90 syntax. To be more specific: When long line is of code is generated 'number' sign is used to continue on the new line. In fortran 90 '&' sign is expected. i.e. fortran 77: #2*rho1(i+32 #)*rho1(i+11)-0.2037715763 instead we need in fortran 90: & 2*rho1(i+32 & &)*rho1(i+11)-0.2037715763 &

## invalid object in MESH...

I just uploaded the file: 2510_CDR_MESH_problem.mw. I'm running Maple 10.05. The problem is more curiosity and annoyance than practical, at this point, but: If I remove the with(RealDomain) at the top of the file, everything runs fine and a nice plot is produced. Keeping the with(RealDomain) statement, results in ERROR, invalid object in MESH. Can anyone tell me what's going on? Don Ritchie

## Animate a Scene...

I need to put all these things together to make a scene, I would like to keep the house,and the clouds as a background plot, and have the tornado and tire move. Sort of like the tornado picks up the tire and then drops it. here is my code its to big for me to save it on here. Using like the animate code, and display codes. Packages: with(plots):with(plottools): Tornado: Actual Tornado: tubeplot([20*t*cos(t),20*t*sin(t),20*t], t=0..20*Pi, radius=-100*exp(.00001*t), tubepoints=10, numpoints=100, color=grey, frames=30): Animated Tornado: rotating around: animate(tubeplot,[[20*t*cos(t+s),20*t*sin(t+s),20*t+s],

## Maple 11 Physics Package: Indicial Notation Deriva...

I need to calculate derivative of a scalar function psi, which depends upon the scalar theta and tensor G[i] using the diff command and indicial notation capability of the recently included Physics package. My actual equation is longer, but here I am only including the terms needed to present my question. Please see below:

restart;

with(PDEtools):

> with(Physics):

Setup(dim=[3,+],spacetimeindices=lowercaselatin);

## Keep scaling and view when plot is within an array...

The code below is just to illustrate the issue. Is there any way to keep the chosen scaling and view when the plots are placed within an array? As the code below will show the scaling and view for a plot in an array has a mind of its own! I tried plotting a and b with both plots in them but with one in white - so it looked as if there was only one plot - but that did not work. restart; > with (plots): a:=plot(x^2/10,x=1..50,scaling=constrained,view=[0..120,0..800]): > b:=plot(-x^2+50*x,x=1..60,color=green,scaling=constrained,view=[0..120,0..800]): > display(a,b); > > g:=array(1..2):

## Efficient parametrization of unitary matrices...

Hello Maple community, although I'm using Maple (now version 11) for quite a while now, I still have problems in designing and writing efficient procedures. Within the context of quantum information theory, I want to write a procedure that parametrizes unitary matrices of arbitrary dimension NxN (in order to perform an optimization over this space). For the beginning, I just want to create random unitary matrices of a given dimension. For this, I implemented the formulas for the "Generalized Euler angle parametrization" (math-ph/0205016). This involves first the creation of N^2-1 matrices that serve as generators for SU(N) and, in a second step, several matrix exponentials and matrix products. These two steps I put in two procedures ("hermitian_basis" and "parametrize_unitary_Euler") (see the linked worksheet).

## There must be a more concise way to use fprintf...

I am writing a large number of variables to file to load into excel - it all works fine - with the code below. But there just has to be a neater way to do it. Can anyone help?
fd:=fopen(writefile,'WRITE','TEXT');
> for t from 1 to nops(files) by 1 do
> fprintf(fd
> ,"%a\t %a\t %a\t %a\t %a\t %a\t %a\t %a\t %a\t %a\t %a\t %a\t %a\t %a\t %a\t %a\t %a\t %a\t %a\t %a\t %a\t %a\t %a\t %a\t %a\t %a\t %a\t %a\t %a\t %a\t %a\t %a\t %a\t %a\t %a\t %a\t %a\t %a\t %a\t %a\t %a\t %a\t %a\t %a\t %a\t %a\t %a\t %a\t %a\t %a\t %a\t %a\t %a\t %a\t \n"

## 3D surface with curves...

I have succeeded in generating a nice plot of a surface in which I am interested, and have calculated geodesics on the surface. Is it possible to display one (or more) geodesic curves on a 3D plot of the surface? If so, would someone point me in the right direction to do so. I've looked at "multiple", but don't see how it's applicable to my problem. Don Ritchie

## No output problem...

I'm using Maple 9.5 (xmaple linux version). I can run application with no errors, but when I try to calculate anything, maple doesn't generate any output or results. Even the simplest examples doesn't work (like 2+2;) What may causes problems? Please help me!!