Hello all,

 

I have a question about converting a continuous piecewise function to Heaviside function, which the function includes trunc() in its conditions.

(I found differentiating piecewise function gives me "undefined" at boundary)

 

When I do that operation (convert(piecewisefunc, Heaviside)) I get the error below.

"Error, (in piecewise/simprootsstep) cannot determine if this expression is true or false: 0 < 183.3333333*Pi"

I noticed, that FileTools[Text][ReadLine] cannot read Cyrillic letter "я" in text files.

My test file containes 6 lines (Codepage 1251):

 Николай Петрович ТРУБЛАИНИ
 "ЛАХТАК"
 Ч А С Т Ь П Е Р В А Я
 НЕМОЙ ПАРОХОД  Г л а в а I
 Ветер налетел неожиданно. С неимоверной быстротой запенились волны. Они приближались к пароходу, стоявшему в миле от берега. Между реями мачт и в надстройках...

Hi,

I am having some problems when solving NullSpace when the matrix is somewhat 'complicated'.

Maple seems not able to find the nullspace.

Any hints or possible workaround?

Casper

 

nullspa.mw

Hello to you all. Pls. i just want to ask you guys about which package in maple can I use to solve nonlinear ODEs Also, can I use the Newtons Method?

Hello,
I'm trying to write a function which is calculating a B-Spline Function. Given is a knot vector U=[u₁,...u_m]. What i want to calculate know is the basis function of degree 0 which is defined by N_i,0(u)=1 if u_i <= u < u_i+1 and 0 otherwise. I tried to do this with two procs which are leading to the same problem:
procVec1 := proc (U)
m := nops(U);
N := [seq(0, i = 1 .. m-1)];
for i to m-1 do

Hi,

The subs command is not working properly for Vector type, see worksheet.

I can use simplify instead, but that's not what I really wanted.

Download vsubs.mw

 

Casper

I'm sharing this in the hope it might help someone (my future self being the most likely). Since my suggestions are not perfect and a little messy, feel free to suggest better ways.

I spend a great deal of time tweaking my plots. Oftentimes I want to add labels to the curves right onto the plot. Most of the time it's easy to do. Occasionally I struggle. Sometimes I succeed, sometimes I give up.

Below is an example of the kind of plot I sometimes create. It's not perfect.

Hi all,

I am having some problems when solving high order polynomials. When oders are 'high' and systems involve multiple variables, Maple is slow to do so.

See in worksheet for detailed codes.

slow.zip

kappa - gives the vector that i am interested in

sC - a reparameterisation which has 'summation' in it

Aim is to verify that it works (it should!)

I currently ask...

Hi,

How do I get ride of these Rootof?

I tried simplify,evala,value,Simplify and ect. Didnt really find anything useful.

Download rootof.mw

 

I dont care which root they actually take, all I want is one of the roots. So I can then use subs for substitution.

Casper

Hi all,

What else could I try if I encounter this error?

Warning:  Incomplete separation.

--------------------------------

 

I read the pdsolve help page, where it says I should have a solution with this warning, but I got nothing but the error.

 

ptr_mplprims.mwHello,I am trying solve  a travelling force problem with pdsolve, but I cannot obtain the second derivative of the solution. I obtained the first derivative, with help from another post (http://www.mapleprimes.com/questions/80997-Derivative-From-Numeric-PDE-Soln#comment81512). When I tried doing the same thing for the second derivative it didn't work. Any sugestions would be helpful. Thank you!!!

Say I have the equation:

f:=x^5+a*x^4+b*x^3+c*x^2+d*x+e

and I want to introduce an identity namely

x^3:=1

Since

subs(x^3=1,f)

or

eval(f,x^3=1)

doesnt work I wonder what is the most elegant way to implement this?

Why does maple not simplify this expression any further:

-4*cos((1/5)*Pi)*m^3-4*cos((1/5)*Pi)*n^3-4*cos((1/5)*Pi)*p^3-4*cos((1/5)*Pi)*q^3+4*cos((2/5)*Pi)*m^3+4*cos((2/5)*Pi)*n^3+4*cos((2/5)*Pi)*p^3+4*cos((2/5)*Pi)*q^3-10*cos((1/5)*Pi)*p*q^2+10*cos((2/5)*Pi)*m^2*n+12*cos((2/5)*Pi)*m^2*p+12*cos((2/5)*Pi)*m^2*q+12*cos((2/5)*Pi)*m*n^2+10*cos((2/5)*Pi)*m*p^2+12*cos((2/5)*Pi)*m*q^2+12*cos((2/5)*Pi)*n^2*p+10*cos((2/5)*Pi)*n^2*q+12*cos((2/5)*Pi)*n*p^2+12*cos((2/5)*Pi)*n*q^2+12*cos((2/5...

Hi,

Say for a 126 by 18 symbolic matrix, substituting numerical values into the matrix DD1 takes about 10 seconds (using time() );

for a 62 by 16 matrix, take just about 1/5 second.

By when the matrix is about 254 by 20, it take much longer! More than a minute!

I never actually waited how long, but I am wondering if there is something wrong? Am I using the right command?

Say the matrix is DD1 with numpar:=[x=0.3,y=0.2,z=0.98,....]

How do i solve this PDE with initial and boundary condition

1. δθ/δζ = δ^2θ/δy^2

At y=0, δθ/δy=0

At y=1, δθ/δy=-µ

At ζ=0, θ=1