how are iterated functions represented in maple? as in f(f(f(x))) is (x)  in conventional notation where by the reader knows it is refering to the iteration conducted 3 times on the argument x, but what does maple use to differentiate between iteration ,exponentiation and differentiation?

Hello 

can I get values from combobox?

for exemple: if I select "X" in combobox, it returns me "a:=1".

But, I'd like to put this comand inside the combobox and dont in the worksheet..

thanks a lot

Can Maple determine the value of DthetaZero such that the solution to the ODE, for some specific value of t, simultaneously provides the two values theta(t)=Pi and diff(theta(t),t)=0?

sol:=dsolve({4*sin(theta(t))*cos(theta(t))-9.8100*sin(theta(t))-(diff(theta(t), t, t)) = 0, theta(0) = 2*Pi*(1/3), D(theta)(0) = DthetaZero}, numeric)

odeplot(sol,[t,theta(t),diff(theta(t),t)],t=0..5) for trial values of DthetaZero shows that the desired value is

1.0340*Pi <DthetaZero<1.0345*Pi.

Hi 

how can I find equilibria points of nonlineay system?

Like 

x'=sin(x)+y

y'=y^2-x

I modelled a telecamera and line follower sensors in Maple in order to calculate the "error" for my PID controller. Know i would like to share this information with the PID in MapleSim but I have no idea how to do it. Is there a way to import maple libraries into MapleSim?

Thanks!

Hi,

I'm trying to export a plot using the open maple api but it looks like open maple API doesnt support certain specific features.

Eg. "Export(\"images\\\result1.gif\", plot(sin(x), title = \"The sine function\", thickness = 3, gridlines=true));"

Above works fine when executing in actual maple application (i.e. correctly exports with gridlines) however doing the same via open maple api it does export the chart but not the specified gridlines.

Had the same issue when setting axis options to show log instead of linear. 

Did anyone else get this? Is this a known issue with open maple api? Is there workaround available?

Thanks,

Bidur

I know that whattype() is used to find the basic data type of an expression. Unfortunately that information is rarely useful. How can I dig down deeper and get Maple to tell me more about the expression?

I read somewhere that there is a properties() procedure that does that but I cannot find that procedure.

Thanks.

Quite accidentally I discovered incorrect calculation of the simple definite integral:

int(1/(x^4+4), x=0..1);  

evalf(%);

                            1/8*ln(2)-1/16*ln(5)+1/32*Pi+1/8*arctan(1/3)   # This is incorrect result

                                                   0.1244471178

Is this a known bug?

If  first we calculate corresponding indefinite integral, and then by the formula of Newton - Leibniz, that everything is correct:

F:=int(1/(x^4+4), x):

eval(F, x=1)-eval(F, x=0);

evalf(%);

                                             1/16*ln(5)+1/8*arctan(2)

                                                     0.2389834593

I have the following problem consisting of multiple seteps.

I have a vector equation consisting of n equations with n parameters (a[n]). Usually the n <= 15. As example data I will use the case n=4.

equations := Vector[column]([ a[1], a[2], a[3],a[4]])-Vector[column]([ b[1], b[2], b[3],b[4]])=0;

The first thing I want to create is a matrix with a format 2^n x n (here: rows=16 by columns=4). The matrix only consists of ones and zeros which contains all possible combinations of ones and zeros. E.G. for n=4

subsMatrix := Matrix([[ 0 , 0 , 0 , 0 ],[ 1 , 0 , 0 , 0 ],[ 0 , 1 , 0 , 0 ],[ 0 , 0 , 1 , 0 ],[0 , 0 , 0 , 1],[1, 1 , 0 , 0],[1, 0 , 1 , 0],[1, 0 , 0 , 1],[0, 1 , 1 , 0],[0, 1 , 0 , 1],[0,0,1,1],[1, 1 , 1 , 0],[1, 1, 0 , 1],[1, 0 , 1 , 1],[0, 1 , 1 , 1],[1, 1 , 1 , 1]]);

Question 1: How do I create such a matrix for the general case? I have absolutely no idea how to achieve this with Matple

The next thing I want to do is to use the rows as substitution equations for the a[i] values, only if the value of the subsMatrix is 0. E.G. in the first case I want to set a[1]=a[2]=a[3]=a[4]=0, then a[2]=a[3]=a[4]=0, then a[1]=a[3]=a[4]=0, and so forth and save the equation as a new equation

I tried the following:

rows:=RowDimension(subsMatrix);

columns:=ColumnDimension(subsMatrix);

for i from 1 by 1 while  i<=rows do

                 subsEquations[i]:=equations

                 for j from  1 by 1 while  j<=columns do

                     if subsMatrix[i,j] =0 then

                          subsEquations[i]:= subs(a[j]=subsMatrix[i,j],subsEquations[i]) 

                     else      

                          #do nothing if the value in the subsMatrix[i,j]=1

                     end if

                 end do:    

end do:

Question 2: What is my error? Maple says the loop is indeterminate. But I don't see why it is not working.

I would be thankful if someone could help me out. I am open to other kind of strategies to this problem :).

what would i write if i wanted to display the full list of variables that be specified by calling kernelopts? like as output in the interface, i naively attempted ops(kernelopts)  which didnt work of course.

hi...

pleaase help me for dsolve equations...

expected.mw

Download expected.mw

Give this

ode:=diff(y(x),x)=a*cos(y(x))+b;
sol_1:=2*arctan( (a+b)/sqrt(b^2-a^2) * tan(1/2*sqrt(b^2-a^2)*(x+_C1)));
sol_2:=2*arctan( sqrt(a+b)/sqrt(b-a) * tan(1/2*sqrt(b^2-a^2)*(x+_C1)));

sol_1 and sol_2 are the same. Only difference is that I wrote  (a+b)/sqrt(b^2-a^2) in one, and  sqrt(a+b)/sqrt(b-a) in the other. But these two expressions are the same. But odetest gives zero on the first and not on the second:

odetest(y(x)=sol_1,ode);
       0

odetest(y(x)=sol_2,ode);
       not zero 

Why did Maple not verify sol_2?

Maple 2016.1 on windows 7

Can we calculate the following equations in Maple?

Substituting equations (21) and (22) into (17), and then obtain equation (23). How to do that? I have done this, but the results are complex and large. They are not in a sum form, but in an expansion form. The reference and the maple file are attached.

Hope for your help.

Best wishes,

Kang

Dynamic_buckling_of_thin_isotropic_plates_subjected_to_in-plane_impact.pdf

gg.mw