Hello,

i need to represent a circle using the command [geometry] circle because i have a problem and i have to calculate an 

intersection between two circles whit command intersection() which is ruled by Package geometry.

For example, with the first circle  i did like the help page says

 But it's Error:

centre of circle(3300;2200)

radius=110

I don't understand the eror. Can you help me?

Thanks in advance.

Hello!

I have a question about densityplot.

I want to get this colormap:

As I understand, I should use plots:-densityplot(...) comand and "HSV" colorscheme, where H = [240..0], S=1, V=1.

But if i use zcoloring with this options, I will get wrong result.

My code:

restart;

a := 0; b := 1; #first and final point

plots:-densityplot(z, dummy = 0 .. 1, z = a .. b, grid = [2, 10], size = [90, 100], colorscheme = ["zcoloring", [proc (z) options operator, arrow; -240*(z-a)/(b-a)+240 end proc, proc (z) options operator, arrow; 1 end proc, proc (z) options operator, arrow; 1 end proc], colorspace = "HSV"], style = surface, axes = frame, labels = ["", ""], axis[1] = [tickmarks = []], title = "Test", titlefont = ["Calibri", "Bold", 16], axesfont = ["Arial", 14], size = [100, 500]); #densityplot with zcoloring option.

My result (zero must be equal to "Blue"):

I can't find mistake....

I am trying to model a disease. The equation is as follows:

S*X - f(X,S,Sp) = 100

I have data for S, I have data for X and I have data for f(X,S,Sp) however I want to find an equation for f(X,S,Sp) that has the best fit with the data because I need to use it later on in my calculation. If anyone is intrested S is the sensitivity of the blood test, Sp is the specificity of the blood test. This means that X*(1-Sp) is the number of false positives.

I currently dont have access to Maple hence I am doing all my modeling in excel 2016. So I am severly limited because excel is useless at algebra.

Maple.xlsx

Hello,

How can I rotate vertically label of vertical axis ? Can you help me ?

Thank you.

I use maple 2016 on linux with X.  When minimized, the maple icon is very small.  Also, the help icon is very small.

Are larger icons available?

The maple icon is ./bin/Maple2016.png.  I can not find the help icon.  Any ideas?

I am trying to calculate the integral

where

Maple cannot calculate the integral. I tried to expand theta in the series form and substitute in the integral, still cannot calculate it.

any suggestion to tackle this problem whould be helpful.

Thank you

I have a PDE with boundary conditions, from a NASA paper.  I always seem to have problems expressing the bc.

PDE := diff(u(x, t), t) = (1/4)*exp(2)*exp(-u(x, t))*(diff(diff(u(x, t), x), x))/(x^2+2);

The initial/boundary conditions are

@t=0, u(x, t) = 2-2*ln(-x^2+2)

@x=0, diff(u(x,t),x)=0  ## this is the bc I have problem expressing

@x=1, u(x,t) = 2+ln(1+t)

The exact solution given in the paper:

2 + ln(1+t) - 2*ln(2-x^2)

I tried

ics := u(x, 0) = 2*(1-ln(2-x^2));

bcs := D[1](u(0,t))=0, u(1,t)=2+ln(1+t);

PDEtools[Solve]([PDE,ics,bcs]); ## no solution

How do I do this?

Tom Dean

We have just released an update to Maple.  It includes updates to the Maple Workbook, the video component, the Physics package, and many other small improvements throughout the product. It is available through Tools>Check for Updates in Maple, and is also available from our website on the Maple 2016.2 download page.

eithne

fn1 and gn1 are the 2x2 matrices. For example
 

fn1:=Matrix(2,2,[seq(f[i],i=1..4)])
gn1:=Matrix(2,2,[seq(g[i],i=1..4)])


eq1:=evalm(Matrix(2,2, [1, 1, 0, 3])&*fn1+gn1)=Matrix(2,2,[0]);

eq2:=evalm(fn1+gn1)=Matrix(2,2, [0]);

how can we find fn1 and gn1 matrices?

Consider the following code:

LM := [
   Matrix([[1,2],[3,4]]),
   Matrix([[5,6],[7,8]])
];
A := Matrix([[0,1],[1,0]]);
map(x -> A . x,LM);
A .~ LM;

where LM is a list of two matrices (just a test example), and A is some (test)matrix that I want to multiply onto each of these two matrices from the left, say. The map-construction works, as expected, but the elementwise operation .~ produces an error. Why?

Greetings

How can I get LPSolve to output the unique subsets of {3,1,1,2,2,1} which sum to 5 (no recycling of set values)

partition.mw

(the code is a Yury/Love hybrid).

I have several maple worksheets (from the web) that have discussion blocks mixed within executable blocks.

All the executable blocks are delineated with a single '[' at the left while the discussion blocks do not.

How do I do this?

Tom Dean

I wish to apply several i-j constraints to an optimization problem that involves minimizing a function x[i,j]. 

Does anyone know of a simple way to exclude values for i and j? For instance, how do we specify the conditions, i not equal to j, i is not equal to 1, etc.?

Thanks in advance!

Hi all, i wan to write getCoeff() function get coefficient general.

Example

f := a^2*b^2*c^2 + 2*a^2*b^2 + 2*a^2*c^2 + 2*b^2*c^2 + a^2 - 6*a*b - 6*a*c + b^2 - 6*b*c + c^2 + 8

getCoeff(f,a^2*b^2*c^2) return 1.

getCoeff(f,a^2*b^2) return 2.

getCoeff(f,a*b) return -6.

getCoeff(f,a^2) return 1, ...

and how to get coefficients freedom ?

Thank you very much.

can anyone run my code?
please do it and send it for me.
thanks.

restart;
with(plottools): with(LinearAlgebra): with(plots):
ode := `assuming`([diff(Y(X), `$`(X, 2))+2*alpha*(diff(Y(X), X))+beta^2*Y(X) = 0], [alpha >= 0, beta >= 0, alpha+beta > 0]):
F := unapply(solve(subs({X = x, Y(X) = y, diff(Y(X), X) = yp, diff(Y(X), `$`(X, 2)) = yz}, ode), yz), x, y, yp):
Fp := unapply(solve(subs({X = x, Y(X) = y, diff(Y(X), X) = yp, diff(Y(X), `$`(X, 2)) = yz, diff(Y(X), `$`(X, 3)) = yt}, diff(ode, X)), yt), x, y, yp, yz):
Ni := seq(i, i = 0 .. 9), 15, 20:
for ni in Ni do
print(ni);
st := time[real]();
f[0, ni] := F(x[0], y[0, ni], yp[0, ni]);
fp[0, ni] := Fp(x[0], y[0, ni], yp[0, ni], f[0, ni]);
f[1, ni] := F(x[1], y[1, ni], yp[1, ni]);
fp[1, ni] := Fp(x[1], y[1, ni], yp[1, ni], f[1, ni]);
y[2, 0] := y[0, ni]+2*h*yp[0, ni]+(6/5)*f[0, ni]*h^2+(4/15)*fp[0, ni]*h^3+(4/5)*f[1, ni]*h^2+(4/15)*fp[1, ni]*h^3;
yp[2, 0] := yp[0, ni]+2*f[0, ni]*h+(2/3)*fp[0, ni]*h^2+(4/3)*fp[1, ni]*h^2;
for j to ni do
f[2, j-1] := F(x[2], y[2, j-1], yp[2, j-1]);
fp[2, j-1] := Fp(x[2], y[2, j-1], yp[2, j-1], f[2, j-1]);
y[2, j] := y[1, ni]+h*yp[1, ni]+(7/20)*f[1, ni]*h^2+(1/20)*fp[1, ni]*h^3+(3/20)*f[2, j-1]*h^2-(1/30)*fp[2, j-1]*h^3;
yp[2, j] := yp[1, ni]+(1/2)*f[1, ni]*h+(1/12)*fp[1, ni]*h^2+(1/2)*f[2, j-1]*h-(1/12)*fp[2, j-1]*h^2;
end do:
Ms := Matrix(4, 4); Ms[1, 3] := 1; Ms[2, 4] := 1;
y[2, ni] := collect(algsubs(h*alpha = H1, expand(algsubs(h*beta = H2, expand(y[2, ni])))), {y[0, ni], y[1, ni], yp[0, ni], yp[1, ni]});
Ms[3, 1] := coeff(y[2, ni], y[0, ni]);
Ms[3, 2] := coeff(y[2, ni], yp[0, ni])/h;
Ms[3, 3] := coeff(y[2, ni], y[1, ni]);
Ms[3, 4] := coeff(y[2, ni], yp[1, ni])/h;
hyp[2, ni] := collect(algsubs(h*alpha = H1, expand(algsubs(h*beta = H2, expand(h*yp[2, ni])))), {y[0, ni], y[1, ni], yp[0, ni], yp[1, ni]});
Ms[4, 1] := coeff(hyp[2, ni], y[0, ni]);
Ms[4, 2] := coeff(hyp[2, ni], yp[0, ni])/h;
Ms[4, 3] := coeff(hyp[2, ni], y[1, ni]);
Ms[4, 4] := coeff(hyp[2, ni], yp[1, ni])/h;
sol := Eigenvalues(Ms);
print(time[real]()-st);
st := time[real]();
SR[ni, 1] := implicitplot(max(seq(abs(sol[ii]), ii = 1 .. numelems(sol))) <= 1, H1 = 0 .. 3, H2 = 0 .. 3, filledregions, gridrefine = 3, axes = Boxed, view = [-2 .. 3, -3 .. 3], labels = [H[1], H[2]], labeldirections = ["horizontal", "vertical"]);
SR[ni, 2] := implicitplot(max(seq(abs(sol[ii]), ii = 1 .. numelems(sol))) <= 1, H1 = -2 .. 3, H2 = -2 .. 3, gridrefine = 3, axes = Boxed, view = [-2 .. 3, -3 .. 3], labels = [H[1], H[2]], labeldirections = ["horizontal", "vertical"]);
print(time[real]()-st);
end do;
for i in Ni do
i;
display({SR[i, 1], SR[i, 2], line([-1, 0], [3, 0], color = red, linestyle = dash), line([0, -3], [0, 3], color = red, linestyle = dash)});
end do;
display({seq(SR[i, 2], i = 0 .. Ni)});