Hello,

Good day.

How to avoid float(undefined) for v3, v4,v5 in this problem.

Thank you in advance.

Try_for_Second_Grade_Fluid.mw

Often, I'd like to use variable names that look like expressions. Is there a way to convert them to some form of inert form or as some sort of literal (so that they are not a mathematical expression) ?

Such as,

a1⁽²⁾

Can't type it here, but I wanted 'a' subscript 1 superscript (2). I'd like it to not be a1 squared.

Basically, I'd like the subscripts and superscript to not mean anything mathematically . . . And, I use a1^(3), a1^(1), a2^(1), a2^(2), a2^(3), b2^(3), etc.

Thanks, for any suggests.

Cheers !!

Hi,

I am tring to  solve a set of boundary layer equations with boundary conditions using Runge kutta Felbergh 45. When I executed the file,  the following message appear " Error, (in dsolve/numeric/bvp) initial Newton iteration is not converging". Can someone help me on this matter?

Sorry for the bad format, maple input is not working.

In particular,from an expression, something like

 Int(x*f(x), x = 0 .. 1)+ Int(x, x = 0 .. 1/3)+3* Int(x*f(x), x = 0 .. 2/3)

I want to extract 

x*f(x)+x+3*x*f(x)

That is all the integrands occuring in the expression. GetIntegrand helps to find the integrand but only for one integral, how do I do it for an expression like above.

I tried to apply following approach

subs(sin(c::anything)=c, sin(x)+f);

and the output was

f

I was expecting to get only 'x+f' for output.

EDIT 1: 

Thank you so much for your help. You guys answered exactly what I asked for. I needed this to do something different but I should have been more careful. I realized, I could not get that part now. This is what I actually need to do, if

A:=-(5/8)*x*(Int(f(x), x = 0 .. x))+(5/24)*(Int(f(x), x = 1/3 .. x))-(1/4)*x*(Int(x*f(x), x = 1/3 .. x));

then I wish to get a function, g(xi),

g(xi)= -(5/8)x*f(xi) ;   if 0<= xi <= x
                                                  (5/24)*f(xi)-(1/4)*x*xi*f(xi) ; if 1/3<= xi<= x

Notice, all the terms after integral should use variable 'xi' and terms occurring before integral remains as it is.

This is the simplest method to explain numerically solving an ODE, more precisely, an IVP.

Using the method, to get a fell for numerics as well as for the nature of IVPs, solve the IVP numerically with a PC, 10steps.

Graph the computed values and the solution curve on the same coordinate axes.

y'=(y-x)^2, y(0)=0 , h=0.1

Sol. y=x-tanh(x)

I don't know well maple. 

I study Advanced Engineering Math and using maple, but i am stopped in this test.

I want to know how solve this problem.

please teach me~ 

IT IS EULER's method

Sum(a^(k/a^k), k= 1..n);

Hi,

I am new to Maple and have a problem when solving three equations with three variables. But when  I plug in into solve function then it gives no answer.

eqn1 := 24900 = A*exp(-X*1.293995859*10^22)+A*exp(-Y*1.293995859*10^22)+5852.27;

eqn2 := 6000 = A*exp(-X*1.293995859*10^22)+2422.929937;

eqn3 := 19100 = A*exp(-Y*1.293995859*10^22)+8275.199937;

Variables are [A,X,Y]

Hi there. I'm Student

i want to know how solve this problem.

please teach me! 

y'=(y-x)^2, y(0)=0, h=0.1

sol.y=x-tanh(x)

how solve this problem for maple? 

please teach me~

Hi!

I want to select 'Export using shapes for greater fidelity' under option, Export. But I can't find the tab ' Export to PDF-Format'. I'm using Maple 18 on a Mac-computer. 

Can anyone help?

Thanks

Esben 

Hello maple users,

I have 2 functions and each functions has 8 variables. I run a matlab code and get outputs for different values of these variables. I assumed 3 of them as constant because the combinations are too many. Anyway, I plot the results and I can see that one function is much better than the other. But I need to compare these functions mathematically. I need to show some proofs. Has anyone any idea what should I do? I wrote the functions on maple and take derivative with respect to one variable and try to see the reaction of the functions to that variable. i am confused.

Thanks

The details of the tasks are explained in the maple file attached but the aim is essentially to model the carbon cycle using first order diff eqs. I'm slightly confused as to how to exactly set up the equations for part a) and b). I've set up the required constants for the equations and the initial conditions as follows: 

#### initial conditions
atmos(0):=750;
bios(0):=600;
soil(0):=1500;

##### coefficients for rate of change
terrPhoto:=110/atmos(0);
terrResp:=110/bios(0);
plantDeath:=55/bios(0);
plantDecay:=55/soil(0);

and one of the equations as :

Diff(atmos(t),t):=terrPhoto*atmos(t); 

but I've been told that I would have to accommodate the direction of flow of carbon in the rates and also reconsider how many equations I would need.  hwk16.mw

I thought there is a way to set j as the imaginaryunit with a scope larger than the current file. There is a startup script or something ?

Anyone have a quick answer (other than no : ) ?

Thanks, cheers !!

what should I do with this error:

"the specified procedure could not be found"

"the Kernel loader cannot find maple engine library,maple.........."

This error appears at the beginning of  use ! 

I've created compiled and executed Fortran 77 code, and then created a .dll file - using g77, for calling as external function in MAPLE 18. I have received the following : Error loading external library. Details are below. Can anyone explain what is going wrong?

Below is the history the steps I have taken:

Here is the contenct of my FORTAN source code file: test2.for 

PROGRAM MAIN
REAL x,y, mult
x = 4.0
y = 3.0
OUT = mult(y,x)
WRITE(UNIT=*,FMT=11) OUT,x,y
11 FORMAT(1X,3E12.4)
END

function mult( a, b )
REAL a,b, mult
mult = a*b
END

The compile, execute and shared library creation steps are as follows  (using g77):

g77 -v -Wall -c -malign-double test2.for
g77 -v "test2.for" -o "test2" 
..execution ran successfully. Creation of dll:

g77 -s -o "test2.dll" "test2.for"

...this executed successfully

Defining as external function in MAPLE:
fmult := define_external('mult', LIB = "S:/MRBwork/IT/Fortran/projects/MAPLE - Fortran/CERN primes/test2.dll", FORTRAN, 'a'::(float[4]), 'b'::(float[4]), RETURN::(float[4]))

... but received following error.

Error, external linking: error loading external library S:/MRBwork/IT/Fortran/projects/MAPLE - Fortran/CERN primes/test2.dll: @�b%

Can someone take and look at the above and explain what may be causing the erroo ion the loading the .dll file?

Melvin

When I export to latex a matrix  <<a|b>,<c|d>>, the latex uses \begin[ and \end]

\left[ \begin {array}{cc} a&b\\ \noalign{\medskip}c&d\end {array} \right]
Is there a way to make Maple use () parenthesis instead of []? The screen display is not important for me in Maple, but I'd the latex to use () instead.  It will be nice if there is way to configure this. I looked but could not find an option.