I have a problem using dchange when my variable depend on two (or more variables) and I would like to apply the chain rule.

For example, when I use the command

I would expect something like 

But I get an error saying that the number of new variables and transformation equations must be the same.

Any idea how I could solve it? 

Thanls a lot for your help.

Hi I have this code

 psi:=proc(n,x);
 (1/sqrt(sqrt(pi)*2^n*factorial(n))*exp(-x^2/2)*HermiteH(n,x))
 end proc;
 psi := proc(n, x) exp(-1/2*x^2)*HermiteH(n, x)/sqrt(sqrt(pi)*2^n*n!) end proc

 psi2=proc(a,x);
 psi(a,x):=(1/sqrt(sqrt(pi)*2^a*factorial(a))*exp(-x^2/2)*HermiteH(a,x))
 end proc;
psi2 = (proc(a, x)
    psi(a, x) := exp(-1/2*x^2)*HermiteH(a, x)/sqrt(sqrt(pi)*2^a*a!)

end proc)
 for n from 0 to 2 do;
 for a from 0 to 2 do;
 result=proc(n,a);
 result(n,a)=psi*psi2
 end proc;
print(evalf(int(result(n,a),x=0..infinity)));
od;
od;

it returns

I know the results for (0,0), (1,1) and (2,2) should be 1 and the rest should be 0.

Can anybody help fix this please

When function is given as two variables, how to find extremas? help thanks

example: z=x³+y³-3xy

and alse the function as given condition z=x+2y, x²+y²=5

i need to solve for u[i+1] as i attached i wrote the equations but i cant get any answers for it, the delta t is 0.1 and i need to go for ten steps, thank you
 

Download hw_4_structural.mw

I need some help. I'm trying to solve this system of equations, but maple says the solutions may have been lost. Here are the equations:

Hi all,

I tried to fit my data (x,y) with a model by using Minimize the Chisquare. By example the model is y=a*x+b, Chisquare is (y-yexp)^2. And I performed a function Minimize(Chisquare) to have a and b.

I need to extract the error of parameter like a±aerror, and b±berror.

Thank you for your helps,

Best regards,

Usually maple displays legend as either a colored line or symbol. If pointline is used in the structure of the command the plot is displayed as both point and line while the legends appear as a colored line, Is there a way in which the curve will combine both point and line and the legend(s) will be strictly point?

Thank you and kind regards

Hi everybody, 

I have a continuous function f of a single variable (all the details can be found in the attached file) and I want to build a more regular approximation of it (let's say F). The construction process ensures that F is C-infinite.

When I plot f and F (command "plot"), for visual comparisons, the F curve presents "holes", that is intervals where there is no plot.
However, the value of F(x) for any x in those void ranges is a real just as F(y) is for any y in a plotted interval.

Note that this phenomenon does not appear  when I use PLOT(CURVES(...)) for F (attached file)

I guess I probably use "plot" in a wrong way, or maybe some option I don't know could prevent it to happen ?

Could you please have a look to the attached file ?
I look forward for your response.


LacunaryPlot.mw 

Assume you have a matrix A and somewhere you want to make a copy of it like B and working with them independently. Let's say you have a loop and after doing a proc on B again you have to make it equal to A. So changes on B shouldn't effect on A. What is the common way of taking such copies of A in Maple?

The following methods don't work.
 

A:=Matrix(3);
B:=A;
B(1,1):=1;
A;

A:=Matrix(3);
B:=subs(B=A,B);
B(1,1):=1;
A;

What I came up with is the following but it will look weird if one really needs to write something meaningless like *2/2.

A:=Matrix(3);
B := (1/2)*subs(B = 2*A, B);
B(1,1):=1;
A;

Dear Maple community,

I've added a label to one of my plot similar to . How can I prevent Maple from rearranging it to ? I think it might have something to do with typeset..?

Thank you very much for your support!

Claudio

Dear Maple community,

I just recently purchased Maple 2016.2 Student Edition for my bachelor thesis and ran into an issue I was unable to resolve myself, maybe I didn't find the right English search terms..?

I need to use a small greek gamma with a horizontal bar above it. I know how to use accents, though, in output the bar is missing and this seems to apply for gamma ONLY. Is it just me or is it a bug maybe? I used exactly the same procedure to enter all variables.

The same problem returns when I try to add gamma to a plot label, so I think it's somehow connected.

From what I gathered so far, maybe it's possible to work around by editing some sort of Maple source code..? But I wouldn't know how to do that, so any help would be very much appreciated!

Thanks in advance and best regards from Germany

Claudio

While coding I used _ instead of subscript which I now want to change to create a presentable document.

Does anyone know how I can change all underscores to subscripts at once without going through every single element?

greetings,

Vince :)

What's the best way to read data from a text file where say there are 3 columns separated by say 5 spaces.  However the first column is a column of names, just as a simple example

green beans     50     12
potatoes     20     15
red peppers     10  10
tomatoes     5     5

readdata takes each space as a column separator.

readdata("c:/test.txt",string,3)
                                     

How do I work it so that I keep the name identifiers in one column?

***
Using ImportMatrix I keep getting error
ImportMatrix("c:/beantest.txt",delimiter="     ")
                              Error, (in ImportMatrix) cannot interpret file
 

I am trying to use global optimization to solve a problem, but get an error:
 

> GlobalOptimization:-GlobalSolve(R, {eq}, h = 50 .. 10000, R = 50 .. 10000, maximize);

Error, `GlobalOptimization` does not evaluate to a module

What is meant by this error?

I am wondering if I can use MAPLE to solve PDE set with one initial value problem for "q" and a boundary condition problem for "p". "q" need to be integrated over time, and for each time step, after updating "q", I need to solve poisson equation for "p":

diff(q(x,y,t),t)=-diff(p(x,y,t),x)*diff(q(x,y,t),y)/cos(xy)+diff(p(x,y,t),y)*diff(q(x,y,t),x)/cos(y)+b*cos(y)^2*diff(p(x,y,t),x)+F(x,y)

diff(p(x,y,t),x,x)+diff(p(x,y,t),y,y)+c(y)*p(x,y,t)=q(x,y,t)

IC: q(x,y,0)=q0(x,y)

BC: periodic in x, second type BC in y.

Many Thanks!

Wanying