v2i2v_circuit.msim

I try to design a circuit to make a voltage-current-voltage translation. In my assumption, probe1.v is equal to probe2.v and it will generate a current(probe2.v / R4) through NMOS. The NMOS acts as a closed switch. Probe3.v is equal to CV3 and i can get "Probe4.v = CV1 + CV3". However, when the circuit operates, probe3.v isn't equal to CV3 and probe1.v isn't equal to probe2.v. I have tried to rise the differential input resistance and differential amplifier to make the Uin+ close to Uin- in op amp, but it doesn"t work effectively.
In addition, the closed resisitance of NMOS is also taken into consideration and i try to make it pretty below Kohm.

Could you help me fix the problem? 

Please help me solve the following problem about complex numbers with Maple: w= (3+zi)/(2+z) whose geometric representation in the "oxy" plane is a straight line. Calculate module of z. Thank you so much.

Hi,

I have a code (see below) for the following number sequence and want to produce a graph as well as the numerical data, please advise how to do it.

Sequence definition: Lexicographicaly least sequence of nonnegative integers commencing 1,3,5,7 such that any four  consecutive terms are mutually coprime.

The code I have so far is: 

ina := proc (n) false end :

a := proc (n) option remember; local k;

if n < 5 then k := 2*n-1

else for k from 2 while ina(k) or igcd(k, a(n-1)) <> 1 or igcd(k, a(n-2)) <> 1 or igcd(k, a(n-3)) <> 1

do  od 

fi; ina(k) := true; k

end proc;

seq(a(n), n = 1 .. 100);
1, 3, 5, 7, 2, 9, 11, 13, 4, 15, 17, 19, 8, 21, 23, 25, 16, 27, 

  29, 31, 10, 33, 37, 41, 14, 39, 43, 47, 20, 49, 51, 53, 22, 35, 

  57, 59, 26, 55, 61, 63, 32, 65, 67, 69, 28, 71, 73, 45, 34, 77, 

  79, 75, 38, 83, 89, 81, 40, 91, 97, 87, 44, 85, 101, 93, 46, 

  95, 103, 99, 52, 107, 109, 105, 58, 113, 121, 111, 50, 119, 

  127, 117, 62, 115, 131, 123, 56, 125, 137, 129, 64, 133, 139, 

  135, 68, 143, 149, 141, 70, 151, 157, 153

I have tried listplot but for some reason cant get the correct format

Hope you can help

Best regards

David.

eqs.mw

Download eqs.mw

#im tryin to solve 9 equation having 9 varibales but the fsolve doesnt solve for C1 to R4, what i am doing wrong??

I am working on a sequence: seq([seq([a[i,j],b[?]],i=1..3)], j=1..3)], it has in total 9 output of a such as a[1,1],a[2,1],a[3,1],a[1,2],a[2,2],a[3,2],a[1,3],a[2,3],a[3,3], yet I need to the output of b like b[1],b[2],b[3],b[4],b[5],b[6],b[7],b[8],b[9]. I have tried to put something like seq([seq([a[i,j],b[f]],i=1..3,f=1..9)] j=1..3)] but it does not work...

Could someone help me?

Greatly appreciated!

Dear all

I have a power series, the genral term contains sign(sin(n)), 
everything is well defined, but when I apply summation to the general term, i can not see sign(sin(n)), its dropped.. why 

and how deduce the the limit to get the radius of convergence 

Cauchy_criteria.mw

thank you for any help 

Hello,

I'm trying to solve a differential equation with boundary conditions using dsolve. However dsolve return nothing. Any help to understand what's happening?

Thank you!

Here's my code:

eq1:=diff(psi(s),s,s)=t*sin(psi(s))-r*cos(psi(s));
eq2:=diff(x(s),s)=cos(psi(s));
eq3:=diff(y(s),s)=sin(psi(s));

cond1:=x(0)=0;
cond2:=x(1)=d+1;
cond3:=y(0)=0;
cond4:=psi(0)=0;
cond5:=D(psi)(0)=0;
cond6:= y(1)=0;

dsolve({eq1,eq2,eq3,cond1,cond2,cond3,cond4,cond5,cond6});
 

Dear all

I  compute the radius of convergence of power series using maple, 

but the code does not give any result

radius_convergence_PSeries.mw

thank you for any help 

This worksheet animates part of the motion of the classic ladder sliding down a wall.

Please answer the two questions posed in the opening text.

Respondents will need to establish their own link to the DirectSearch package

Slide_Ladder.mw

Hi, I am very new in maple. I want to create a list of 54 quartic polynomials f=x^4 + a_3*x^3 + a_2*x^2 + a_1*x + a_0 with coefficients 0<=a_i<=2 and a_0 <> 0 . 

f := x ->  x^4 + add(a[i]*x^i, i = 0 .. 3);
for m to 54 do
    pol[m] := f(x);
end do;

How do I incorporate conditions 0<=a_i<=2 and a_0 <> 0 into this cycle so I can get 54 different combinations of coefficients? Thank you.

restart;
u := (H(x, t, z)+sqrt(R))*exp(I*R*x);
                /              (1/2)\           
                \H(x, t, z) + R     / exp(I R x)

I*(Diff(u, z))+Diff(u, `$`(x, 2))+Diff(u, `$`(t, 2))+(abs(u)*abs(u))*u-((abs(u)*abs(u))*abs(u)*abs(u))*u;
  / d  //              (1/2)\           \\
I |--- \\H(x, t, z) + R     / exp(I R x)/|
  \ dz                                   /

     / 2                                   \
     |d  //              (1/2)\           \|
   + |-- \\H(x, t, z) + R     / exp(I R x)/|
     \                                     /

     / 2                                   \                    
     |d  //              (1/2)\           \|                  2 
   + |-- \\H(x, t, z) + R     / exp(I R x)/| + (exp(-Im(R x)))  
     \                                     /                    

                       2                                    
  |              (1/2)|  /              (1/2)\              
  |H(x, t, z) + R     |  \H(x, t, z) + R     / exp(I R x) - 

                                        4                       
                 4 |              (1/2)|  /              (1/2)\ 
  (exp(-Im(R x)))  |H(x, t, z) + R     |  \H(x, t, z) + R     / 

  exp(I R x)
value(%);
  / d            \              / d  / d            \\           
I |--- H(x, t, z)| exp(I R x) + |--- |--- H(x, t, z)|| exp(I R x)
  \ dz           /              \ dx \ dx           //           

         / d            \             
   + 2 I |--- H(x, t, z)| R exp(I R x)
         \ dx           /             

     /              (1/2)\  2           
   - \H(x, t, z) + R     / R  exp(I R x)

     / d  / d            \\                             2 
   + |--- |--- H(x, t, z)|| exp(I R x) + (exp(-Im(R x)))  
     \ dt \ dt           //                               

                       2                                    
  |              (1/2)|  /              (1/2)\              
  |H(x, t, z) + R     |  \H(x, t, z) + R     / exp(I R x) - 

                                        4                       
                 4 |              (1/2)|  /              (1/2)\ 
  (exp(-Im(R x)))  |H(x, t, z) + R     |  \H(x, t, z) + R     / 

  exp(I R x)
simplify(%);
  / d            \              / d  / d            \\           
I |--- H(x, t, z)| exp(I R x) + |--- |--- H(x, t, z)|| exp(I R x)
  \ dz           /              \ dx \ dx           //           

         / d            \                 2                      
   + 2 I |--- H(x, t, z)| R exp(I R x) - R  exp(I R x) H(x, t, z)
         \ dx           /                                        

      (5/2)              / d  / d            \\           
   - R      exp(I R x) + |--- |--- H(x, t, z)|| exp(I R x)
                         \ dt \ dt           //           

                                                  2           
                             |              (1/2)|            
   + exp(-2 Im(R x) + I R x) |H(x, t, z) + R     |  H(x, t, z)

                                                  2       
                             |              (1/2)|   (1/2)
   + exp(-2 Im(R x) + I R x) |H(x, t, z) + R     |  R     

                                                  4           
                             |              (1/2)|            
   - exp(-4 Im(R x) + I R x) |H(x, t, z) + R     |  H(x, t, z)

                                                  4       
                             |              (1/2)|   (1/2)
   - exp(-4 Im(R x) + I R x) |H(x, t, z) + R     |  R     
collect(%, exp(I*R*x));
 /  (5/2)       / d            \      2           
 |-R      + 2 I |--- H(x, t, z)| R - R  H(x, t, z)
 \              \ dx           /                  

        / d            \   / d  / d            \\
    + I |--- H(x, t, z)| + |--- |--- H(x, t, z)||
        \ dz           /   \ dx \ dx           //

      / d  / d            \\\           
    + |--- |--- H(x, t, z)||| exp(I R x)
      \ dt \ dt           ///           

                                                   2           
                              |              (1/2)|            
    + exp(-2 Im(R x) + I R x) |H(x, t, z) + R     |  H(x, t, z)

                                                   2       
                              |              (1/2)|   (1/2)
    + exp(-2 Im(R x) + I R x) |H(x, t, z) + R     |  R     

                                                   4           
                              |              (1/2)|            
    - exp(-4 Im(R x) + I R x) |H(x, t, z) + R     |  H(x, t, z)

                                                   4       
                              |              (1/2)|   (1/2)
    - exp(-4 Im(R x) + I R x) |H(x, t, z) + R     |  R     
 

restart;
H := a__1*exp(I*(-Omega*t+k*x+z*k[1]))+a__2*exp(-I*(-Omega*t+k*x+z*k[1]));
I*(diff(H, z))+diff(H, x, x)+diff(H, t, t)+R*(H+conjugate(H))+R^2*(H+conjugate(H))*H;
value(%);
simplify(%);

Download m18bs.mw

Hi,

I'm trying to solve the attached system but I don't know how to proceed.

Any ideas?

Thanks very much in advance.

Best regards,

Download maple_problem.mw

I run Maple 2021 under Ubuntu 20.04 on a new Lenovo laptop with 32Gb of Ram. Every time I start Maple, it runs for a few minutes and then loses the "kernel connection". I have to save the worksheet and re-start Maple. In dmesg, I find:

[ 1436.724570] oom-kill:constraint=CONSTRAINT_NONE,nodemask=(null),cpuset=/,mems_allowed=0,global_oom,task_memcg=/user.slice/user-1000.slice/user@1000.service,task=mserver,pid=8037,uid=1000
[ 1436.724589] Out of memory: Killed process 8037 (mserver) total-vm:31723552kB, anon-rss:31289772kB, file-rss:60kB, shmem-rss:0kB, UID:1000 pgtables:61656kB oom_score_adj:0
[ 1437.151441] oom_reaper: reaped process 8037 (mserver), now anon-rss:0kB, file-rss:0kB, shmem-rss:0kB

indicating that Maple's virtual memory exceeded 30 Gb! This happens even if the only command I execute is, for instance, "resrart" or "A:=1" and nothing else. It also happens when no other applications are running and the "top" command indicates that around 30Gb of RAM is available.

In this state, Maple is utterly useless to me. This was a new install of Maple and a fresh install of Ubuntu on a new laptop, surely I am not the only one seeing this?

I have tried setting a 30Gb limit in "kerneloptions" for "stacklimit" but that di not make a difference.

If you have seen any behaviour like this, please respond. Is there some bug in Maple that leads to oncontrolled and unprovoked memory grabbing?

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;