I am attempting to add the contents of a variable based on the contents of another. There should be some way to do this without looping. I get errors when trying to do this with seq. I seem to not understand evaluation...

How do I do this?

restart;
## generate some values like in the real app
roll:=rand(1..9):
N := sort([seq(seq(10*(2+jdx)+roll(),jdx=1..5),idx=1..10)]):
V := 10*seq(roll()+10*trunc(N[idx]/10),idx=1..nops(N)):

## generate index for sum. This groups the values for sum
sumidx := [seq(floor(N[idx]/10)-2,idx=1..nops(N))];

## create and zero sum variable
S := 0 *~convert(convert(trunc~(N/10),set),list);

## calc sum and display it - This works
for idx to nops(sumidx) do
    S[ sumidx[idx] ] += V[idx]:
end do:
S;

## error because sumidx[idx] is not evaluated ?????
S := 0 *~convert(convert(trunc~(N/10),set),list):
seq('S'[ sumidx[idx] ] += V[idx], idx=1..nops(N));
S;

## This works 'S' delays evaluation and sumidx[idx] is evaluated in
## the function call
f := proc( A, B )
    A += B:
end proc:
## zero sum variable
S := 0 *~convert(convert(trunc~(N/10),set),list):
seq(f('S'[ sumidx[idx] ], V[idx]),idx=1..nops(N)):
S;
 

Hello all,

I am considering the function 

I am also considering the tangent plane  at point (11,-12).

I would like to draw a 3Dplot in maple that shows the tangentplane touching the graph of f(t,u) at point (11,-12). 

I have typed the following :
 

plot3d([exp(t^2 + 10*u - 1), -121 + 22*t + 10*u], t = -1 .. 1, u = -0.7 .. 0.7, color = [red, green])
 

The 3Dplot is not correct. I have spent much time getting it to work. Could someone please assist me?

Thanks.

I can export a worksheet (to many different formats), but the normal way of doing this requires a human in the loop and several mouse operations.

Is there a way to automate this?

I have on the order of 100 different worksheets and would like to capture them in an archival format (e.g., PDF).

I am trying to find the minimum of a function TF defined by a procedure over an interval. The function depends on variable x and fixed parameters x0, L, k, alpha_0, alpha_L. Here is the function

TF := proc(x, x0, L, k, alpha_0, alpha_L) if x0 <= x then evalc(abs(cos(k*(x - L) - alpha_L)*cos(k*x0 + alpha_0)/(cos(alpha_L)*cos(k*x0 + alpha_0)))); else evalc(abs(cos(k*(x0 - L) - alpha_L)*cos(k*x + alpha_0)/(cos(alpha_L)*cos(k*x0 + alpha_0)))); end if; end proc;

When I use

Minimize('TF'(x, 0, 0.03, 55.11566060, Pi/2, Pi/4), x = 0 .. 0.03);

I get an error "Error, (in Optimization:-NLPSolve) cannot determine if this expression is true or false: 0 <= x". What is my mistake ?

Thanks.

> with(LinearAlgebra) :
> a:=<<.1,.2>|<.3,.4>>:
> ScalarMultiply(a,.1);

INTEL MKL ERROR: /home/jet08013/maple2022/bin.X86_64_LINUX/libmkl_gf_lp64.so: undefined symbol: mkl_blas_cdgmm_batch_strided.
Intel MKL FATAL ERROR: Cannot load libmkl_gf_lp64.so.
maple: fatal error, lost connection to kernel

This is EXTREMELY inconvenient.

Download Programm_zur_Brechnung_der_Kreisteilungspolynome_2022-04-05_Ki.mw

Good morning

Why doesn't Quotient(x,y,z) not work within a procedure whereas it works well standing alone? See example.

Greetings  Heinz

Dear all,

I'm using Maple to calculate the geodesics of the Poincare' Half Plane:

restart:
with(LinearAlgebra): with(DifferentialGeometry): with(Tensor): with(Tools): with(plots): 
DGsetup([x,y],M1)
g1 := evalDG(1/y^2*(dx &t dx+dy &t dy))
R1 := CurvatureTensor(g1)
K := SectionalCurvature(g1,R1,D_x,D_y)
Gamma := Christoffel(g1)
C := [x(t), y(t)]
V := GeodesicEquations(C, Gamma, t)
DE := Tools:-DGinfo(V, "CoefficientSet")

simplify(dsolve(DE, explicit))

I receive this error message

Error, (in simplify/siderels:-simplify/siderels) specified variables must be names or functions

How can I fix this error?

Thanks, Nicola

Please, how do I find the minimum of the real part of a complex function? I tried min ( ) function it didn't work. 

Find attached the fileFinding_min_zero.mw
 

Download Finding_min_zero.mw

The random connected graphs used to be connected in Maple 2020. But then ...

restart;
with(GraphTheory):
with(RandomGraphs):
N:=100: n:=20: m:=30:
add(`if`(IsConnected(RandomGraph(n,m,connected)), 1, 0), 1..N) <> N;

        54 <> 100

Hello,

I would like to print the current values of both displayed functions for x=1 in each frame of the animation. My example code is below:

plot1 := animate(plot, [a*x^2, x = -1 .. 1, color = "Green", thickness = 3], a = 0.2 .. 1.2);
plot2 := animate(plot, [a*x^2 + 0.3, x = -1 .. 1, color = "Red", thickness = 3], a = 0.2 .. 1.2);
display([plot1, plot2]);

I would be grateful for any tips.

Thank you,

Iza

Hello all, 

Would you allow me to ask this one question?
[moderator: See also this previous question]

Is there any possible way to treat the differentiation operator (e.g., 'D') as an ordinary coefficient of a polynomial?

For example, as described in the attached worksheet, I was wondering if there is a way to re-write the LHS of the expression 'eq_e5_9b' as the expression 'desired'. 

In Kwon Park 

Download Q20220404.mw

How do I create a pointplot with different values of a parameter?

I tried

pointplot([seq([k, a(k, a0)], k = 0 .. 10, a0 = [0, 50, 100, 150, 200])]);
Error, invalid input: seq expects its 3rd argument, step, to be of type numeric, but received a0 = [0, 50, 100, 150, 200]
NULL;

ImportGraph reads one or more graphs from a file. For a file containing multiple graphs, the supported formats are digraph6, graph6, and sparse6. I notice that one option is "output = graph or list, or iterator". However, in my programming with Maple, I was reminded several times that list is only good for a small amount of data.  

Although I can convert the list to an array using the convert function, the time spent in the conversion process needs to be considered.

restart: 
with(GraphTheory):
L:=ImportGraph("C:/Users/eul10c.g6", graph6, output=list):#31026 connected eulerian graphs on 10 vertices graphs and Change to your path here.
convert(L,Array) 

So does it make more sense to provide an "output=Array" as an output option?

eul10c.txt

I am trying to decide O of times fo a computer process. I thought it was n^2*log(N) or something like that.

With 12  points, it may be hard to determine if O(N^4), etc.

See big-o.mw