25 Reputation

18 years, 42 days

use separated animations...

Hi Eric;

I think this is a good idea:

with(plots);
with(plottools);
omega := 1; k := 5; R := 5; r := 2;

plot1 := plot([R*cos(omega*t), R*sin(omega*t), t = 0 .. 2*Pi]);
Epi1 := proc (t)
display(circle([R*cos(omega*t), R*sin(omega*t)], r, color = red));
end proc;
Epi2 := proc (t)
display(disk([R*cos(omega*t)+r*cos(k*t), R*sin (omega*t)+r*sin(k*t)], .2, color = blue));
end proc;
print(`output redirected...`); # input placeholder
ani1:=animate(Epi1, [t], t = 0 .. 2*Pi, background = plot1, frames = 50, trace = 0, scaling = constrained):
ani2:=animate(Epi2, [t], t = 0 .. 2*Pi, background = plot1, frames = 50, trace = 50, scaling = constrained):
display([ani1,ani2]);

solve...

Hi, f := 5000/(1+99*exp(-.8*t)); g := solve(s = f, t);

use blockmatrix...

You can use blockmatrix command in linalg package.

For example:

with(linalg);

n1 := 2; n2 := 2;

A11 := matrix(n1, n1);
A12 := matrix(n1, n2);
A21 := matrix(n2, n1);
A22 := matrix(n2, n2);

A_big := blockmatrix(2, 2, [A11, A12, A21, A22]);
inverse(A_big);

Re "Error, recursive assignment"...

Correct it as follows:

restart; with(student); with(linalg); A := array(evalf([[2, -1, sqrt(2)], [3, 2, -3], [3, sqrt(2), -15/7]])); B := array(evalf([5+7*sqrt(2), -24, -12-3*sqrt(2)])); B := `<,>`(B); print(A); print(B); N := 3; t := 10^(-6); for j to N do for k from j to N do S := 0; for i to N do S := S+A[i, j]*A[i, k] end do; C[k] := S end do; CC := 0; for i to N do CC := CC+A[i, j]*B[i] end do; for i from j to N do A[i, j] := C[i] end do; C[j] := CC end do; P := (1/2)*sqrt(t*N); for i to N do A[i, i] := A[i, i]+P end do; A[1, 1] := sqrt(A[1, 1]); for j from 2 to N do A[1, j] := A[j, 1]/A[1, 1] end do; for i from 2 to N do S := 0; for k to i-1 do S := S+A[k, i]*A[k, i] end do; A[i, i] := sqrt(A[i, i]-S); for j from i+1 to N do S := 0; for k to i-1 do S := S+A[k, i]*A[k, j] end do; A[i, j] := (A[j, i]-S)/A[i, i] end do end do; C[1] := C[1]/A[1, 1]; for i from 2 to N do S := 0; for k to i-1 do S := S+A[k, i]*C[k] end do; C[i] := (C[i]-S)/A[i, i] end do; C[N] := C[N]/A[N, N]; for i from N-1 by -1 to 1 do S := 0; for k from i+1 to N do S := S+A[i, k]*C[k] end do; C[i] := (C[i]-S)/A[i, i] end do; print(C);

Generators...

Hi, The "Generators" command returns the set of generators in a set. In your Example: with(PolynomialIdeals): J := <{y^2,x*y}>; pd:=PrimeDecomposition(J); is(Generators(pd[1]) subset Generators(pd[2])); #output: true

Plotting direction fields ......

Change them as follows: dfieldplot(diff(y(x), x) = (1-y(x)^2)/(2+.5*x^2), y(x), x = -2 .. 2, y = -5 .. 5, arrows = SLIM, color = black, dirfield = [5, 5]); dfieldplot(diff(y(x), x) = x*sin(x)/(1+y(x)^2), y(x), x = -6.15 .. 6.15, y = -5 .. 5, arrows = SLIM, color = black, dirfield = [10, 10]);

Re...

Hi, you must delete two lines of your procedure : HandleGB :=proc(file) local line, T,L,f,cnt; f:=fopen(file,READ); try T:=table(); #line:=readline(f); #T[cnt]:=parse(line); for cnt do line:=readline(f); if line=0 then break; end if; T[cnt]:=parse(line); end do; finally fclose(f); end try; L:=convert(T,'list'); end;

Re...

But your title is about Maple 13 ! However, I think it is important that we see your worksheet. Maybe these changes are relevant to your problem or your code.

Re...

did you test it in other version?

What is contained in your worksheet?...

Hi, What is contained in your worksheet? This is important,obviously.
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