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,

As you know the matrix calculations of the Matlab is more powerfull than Maple, My question is that is it possible to call Matlab solver from Maple worksheet? I mean, in part of my Maple worksheet (for loop) I need to compute the eigenvalue and square root of a big matrix (order of 1000) that Maple couldnt while Matlab can do it. So it will be so nice if I can call Matlab directly from my ws rather than I export my data and import it to Matlab and calculate and return back to Maple (manualy It is tedious).

Is it possible???

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
 

How do you recommend to calculate the square root of big Matrices (e.g, 300*300) with Maple??

My machine couldnt calculate the square root of Matrices (9*9) as you see below:

Download askkk.mw

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