I have encountered bug in factors/fsolve while working with 19-th degree polynomial: 

restart;

Digits:=150:
T:=-6.22380759047872668130713536877030256364968636070065651396334810246948704517800844289400608484048587112392332204805530128070851889819985512874202683743*10^11*x^15+1.30320674544020861155773378297484119553167774488351680864188235543008368581731239587845304516984389100205019741111280194189829856859808540642557769603*10^10*x^6-4.66269056752439302342961934783764679009596024511170531603537327397832302302620600217387943312388922053304167698527169182278585860427802821480352854136*10^11*x^9-2.23704996926446119043671514798254764988240075983626880645807120500701523185370168392321824617257975062292105400290171941856646211919772527234308968846*10^9*x^5+1.70227750800986164284793608409450414651109713000703213281475661248797845709368255736580952492853671050778821135335145407044800619189451776936359075686*10^12*x^12+2.75132914316444017343930750158891109941047127103886960894939389127711887329536485172215512793127850186551483171384960841607262449527761786758828223621*10^8*x^4-34932.1305741980482332724462824276603543110574918698909627427160477228536038554704823433224807581628905769847550345090785500099182662763447500819501675*x+1.14859089243616386902401277001127426741536679789632050800564282457083136981495352758127041512610195469873039580049988570650313838832989727748112868586*10^12*x^14-6.60479740997269404871863401649844958253760499264982628400515571200965556608668632440745621931354881132921476624343305820884923453724427367494415551238*10^10*x^17-5.62833694496139881587566825658979473046292640751330993837612787833792702707901920475562429114656627532669843830531312111426766840057855202536781521123*10^10*x^7-1.41317084251894030640575308228417182186337397538022537825365672333611503622567981167488384741420461775617951229535582868905095341476313150469092017698*10^12*x^11-8.21268191019727949807038061270674769712976810595535494085869238004490345847174711476348954310804852930678468602300916137608391140935636924900016951244*10^8*x^19+397.252699937115297695173788383107213691513398731729934944369484808586994493337920006396692649274392699364304534062337678482629861430643165733668575822+2.45061767631130714142188028061597642324588736935628490184983950396964320020866945354270367821778753632385377702112725604392839751008695021580743844404*10^11*x^16+1.08699947236093139248842860047684411564605736115175003178583710408973712475471303403438454553797809672473740940054172927497665894877177132800140413775*10^10*x^18+1.84485142971549353599220669614768264648023215439682851036030548807708252959822522849421648368214446092969270608024147362000126035954415744321702508798*10^11*x^8-2.30461084758765666852675422975553976835398815305842562217293737088819307979848024374022174488508670823626363788957243202121075401744096241597591787541*10^7*x^3+9.17691101238967627829517731270700894639677345422963842539705370480050031196020089039807157125184117990094461042715726886282973724309183151499484709563*10^11*x^10-1.59505142070054081045558935086478494555622632474984266672719416019069437321867830698450310020630535513817946854845186492455277659549284062382504657541*10^12*x^13+1.21399269842294123787022397507857250840398420627023248941081275489711499859955449395398103964932227544163416388726749227644470585060488880538430515276*10^6*x^2:

infolevel[fsolve]:=3:
fsolve(T,fulldigits); # <-- completes without issues

factors(T);           # <-- freezes with log:
fsolve: ill-conditioned polynom of degree 19, with 0(0) given roots
fsolve: 1th root found in 9 iters at 165 Digits
fsolve: 2th root found in 11 iters at 164 Digits
fsolve: 3th root found in 11 iters at 165 Digits
fsolve: 4th root found in 10 iters at 174 Digits
fsolve: 5th root found in 10 iters at 167 Digits
fsolve: 6th root found in 11 iters at 168 Digits
fsolve: 7th root found in 11 iters at 174 Digits
fsolve: 8th root found in 11 iters at 170 Digits
fsolve: 9th root found in 11 iters at 181 Digits
fsolve: 10th root found in 11 iters at 172 Digits
fsolve: 11th root found in 12 iters at 175 Digits
fsolve: 12th root found in 11 iters at 182 Digits
fsolve: 14th root found in 14 iters at 177 Digits
fsolve: 15th root found in 10 iters at 176 Digits
fsolve: 16th root found in 11 iters at 173 Digits
Warning,  computation interrupted

The most interesting thing is that standalone 'fsolve' finishes fine, but 'factors' freezes in 'fsolve:-polyill' on the same polynomial.

My system is: Windows 7 x64, Maple 2017.0.

Would appreciate any help on how to avoid the issue with 'factors'.

ode1a := diff(a(t), t) = 1.342398800*10^5*a(t)+round(89591.20000)*b(t)+round(44647.44000)*c(t);
ode2a := diff(b(t), t) = round(89591.20000)*a(t)+round(89803.24000)*b(t)+round(44901.60000)*c(t);
ode3a := diff(c(t), t) = round(44647.44000)*a(t)+round(44901.60000)*b(t)+round(44859.24000)*c(t);
sol := dsolve([ode1a=exp(t), ode2a=exp(t), ode3a=exp(t)], [a(t),b(t),c(t)]);

Error, (in dsolve) invalid input: `PDEtools/NumerDenom` expects its 1st argument, ee, to be of type algebraic, but received diff(a(t), t) = (3355997/25)*a(t)+89591*b(t)+44647*c(t)

initially i guess the error come from decimal number coefficient

but after round it, still have error

ode1a := diff(y1(tt), tt) = 1.342398800*10^5*y1(tt)+89591.20000*y2(tt)+44647.44000*y3(tt);
ode2a := diff(y2(tt), tt) = 89591.20000*y1(tt)+89803.24000*y2(tt)+44901.60000*y3(tt);
ode3a := diff(y3(tt), tt) = 44647.44000*y1(tt)+44901.60000*y2(tt)+44859.24000*y3(tt);

would like to find the origin eigenstate before it collapse to eigenvalues

how to apply ricci flow in this situation?

i find help file , and can not find some relationship between this application and inputs of ricci related function

which functions in maple can help to find origin of eigenstate

iam trying to apply newton method on non liner system but i have a problem for apply while loop inside other while loop 
any help please

hey... can u help me how to solve my problem using the Implicit Crank Nicolson Finite different Method. 1_ques_crank.mw..... problem in variable name A and u .. how to solve this 

Download 1_ques_crank.mw

please see attachment and explain why the output of the 2nd line is not 0
 

Download mod_maple_help.mw

Dear all,

I'm trying to plot dispersion curves in Maple but I'm having some trouble. The code is attached as a file also.

f1  is my main function and I want to plot Vx with regard to f as all the rest are known variables, but I'm not able to do so.

I hope that someone can tell me why do I have this error.

Thanks in advance!

restart;
f1 := (C33*Rp*kzp+C13*kx)*(Rm*kx+kzm)*sin(kzp*h)*cos(kzm*h)-(C33*Rm*kzm-C13*kx)*(Rp*kx+kzp)*sin(kzm*h)*cos(kzp*h)=0;
Rp := (-C11*kx^2-C55*kzp^2+omega^2*rho)/((C55+C13)*kx*kzp);
Rm := (-C11*kx^2-C55*kzm^2+omega^2*rho)/((C55+C13)*kx*kzm);
kzp := sqrt(((-M+sqrt(M^2-4*N))*(1/2))*kx^2);
kzm := sqrt(((-M-sqrt(M^2-4*N))*(1/2))*kx^2);
M := (C11*C33/rho^2-2*C55*C13/rho^2+C13^2-omega^2*(C33+C55)/(rho*kx^2))*rho^2/(C33*C55);
N := (omega^2/kx^2-C11/rho)*(omega^2/kx^2-C55/rho)*rho^2/(C33*C55);
C11 := 0.435e10;
C13 := 0.259e10;
C55 := 0.112e10;
C33 := 0.108e11;
rho := 923;
h := 0.7e-2*(1/2);
kx := omega/Vx;
omega := 2*Pi*f;
f1;
plot(f1, f = 10 .. 0.100e6);
Error, (in plot) unexpected options: [(.4633081900*(-0.1717311166e12*f^2/Vx^2-0.2210791386e11*(...

Asim_dispers.mw

With this application you will learn the beginning of the study of the vectors. Graphing it in a vector space from the plane to the space. You can calculate its fundamental characteristics as triangle laws, projections and strength. App made entirely in Maple for engineering students so they can develop their exercises and save time. It is recommended to first use the native syntax then the embedded components. In Spanish.

Vector_space_with_projections_and_forces_UPDATED_2018.mw

Vector_space_with_projections_and_forces_UPDATED.mw

Movie #01

https://www.youtube.com/watch?v=VAukLwx_FwY

Movie #02

https://www.youtube.com/watch?v=sIxBm_GN_h0

Movie #03

https://www.youtube.com/watch?v=LOZNaPN5TG8

Lenin Araujo Castillo

Ambassador of Maple

Display only the +'ve xyz axis, and also display +'ve axis as a different color than the negative axis.

I am having trouble exporting a matrix.  Attached is my file.  When I export the matrix the values for tpeak are not numeric.  They are string values indicating the analytical expression that MAPLE is displaying.  I cannot seem to find the option to express the results as numeric.

Can anyone help?

untitled5.mw

i have 4 equation and 4 variables with DirectSearch package it will give me a solution but not in a good time
when i try fsolve it just give me a blank
these are my equations :
POL[0] := .42810/(.65429+c[-2])

 POL[1] := -8.4078*c[-1]-162.64*c[0]+84.228*c[1]-6/(.80888+c[-2])^2+9.7066/(.80888+c[-2])^3-3.9257/(.80888+c[-2])^4+(1/2*(.42786*c[-1]+.42786*c[0]+.42786*c[1]+.65429/(.80888+c[-2])))*(-49.180*c[-1]+31.921*c[0]-8.6921*c[1]+2/(.80888+c[-2])-3.2355/(.80888+c[-2])^2+1.3086/(.80888+c[-2])^3)

POL[2] := 53.965*c[-1]+43.012*c[0]-103.98*c[1]-6/(1.+c[-2])^2+12./(1.+c[-2])^3-6./(1.+c[-2])^4+(1/2*(.50000*c[-1]+.50000*c[0]+.50000*c[1]+1./(1.+c[-2])))*(22.229*c[-1]-37.815*c[0]+22.229*c[1]+2/(1.+c[-2])-4./(1.+c[-2])^2+2./(1.+c[-2])^3)

POL[3] := -30.115*c[-1]+43.264*c[0]+52.171*c[1]-6/(1.2363+c[-2])^2+14.836/(1.2363+c[-2])^3-9.1704/(1.2363+c[-2])^4+(1/2*(.52893*c[-1]+.52893*c[0]+.52893*c[1]+1.5284/(1.2363+c[-2])))*(-4.5997*c[-1]+16.892*c[0]-26.026*c[1]+2/(1.2363+c[-2])-4.9452/(1.2363+c[-2])^2+3.0568/(1.2363+c[-2])^3)

i even change digits to 100 but still no awenser

my fsolve syntax

K := fsolve({seq(POL[v], v = 0 .. 2*N+2)})

the awenser fsolve gave me

K:=

thats all it gave me

I'd like to present the following bugs in the IntTutor command.

1. Initialize

Student[Calculus1]:-IntTutor((1+cos(3*x))^(3/2), x);

then press the All Steps button. The command produces the answer (see Bug1_in_IntTutor.mw)

(4/9)*sqrt(2)*sin((3/2)*x)^3-(4/3)*sqrt(2)*sin((3/2)*x)

which is not correct in view of

plot(diff((4/9)*sqrt(2)*sin((3/2)*x)^3-(4/3)*sqrt(2)*sin((3/2)*x), x)-(1+cos(3*x))^(3/2), x = 0 .. .2);

One may compare it with the Mathematica result Step-by-step2.pdf.

2. Initialize

Student[Calculus1]:-IntTutor(cos(x)^2/(1+tan(x)), x);

In the window press the Next Step button. This crashes (The kernel connection has been lost) my comp in approximately an half of hour (see screen2.docx). One may compare it with the Mathematica result Step-by-step.pdf .

Indeed,  "We wanted the best, but it turned out like always" .

I want to use a variant of the arctangent function in odeplot but I run into various problems. Here is the variant called at
> at := proc (x::realcons, yy)

if 0 < x then arctan(yy/x) elif x < 0 then Pi+arctan(yy/x) elif x = 0 then (1/2)*Pi end if end proc;

It would be nice to know if this is really what I want so I try to plot at  values for which I know the answer
> plot(at(-cos(-t), sin(t)), t = 0 .. 3.14);

Error, invalid input: at expects its 1st argument, x, to be of type realcons, but received -cos(t)

I have seen this problem before so I use single quotes with success:
plot('at(-cos(-t), sin(t))', t = 0 .. 3.14);

I get the desired plot;

Now I want to use this procedure in a plot of a numerical solution to an ODE.
The ODE is quite complicated but returns a procedure ,nans, that i use to visualize solutions via commands such as

> odeplot(nans, [[y, f(y)]], y = 0 .. 6);
No problem with any of that,

The problem arise when I define theta below
> theta := at(f(y)-(1/2)*Pi, diff(f(y), y));
and try to use it in odeplot, for example,
> odeplot(nans, [[y, theta]], y = 0 .. 6);
or
> theta1:=y->at(f(y)-Pi/(2),diff(f(y),y));

> odeplot(nans, [[y, theta1(y) ]], y = 0 .. 6);

Maple's complains about theta and theta1 and all of my attempts to fix the problem:

Error, (in plots/odeplot) curve 1 is not fully specified in terms of the ODE solution, found additional unknowns {Theta1}
or
Error, (in Theta1) invalid input: at expects its 1st argument, xx, to be of type realcons, but received f1(y)-(1/2)*Pi  or

Error, (in Theta1) invalid input: diff received HFloat(0.001), which is not valid for its 2nd argument

I supect there is an easy fix. If I give up on at and just use arctan I get an ugly jump in my plot but otherwise everything works.

I am looking for a high accuracy plot, however, and the jump obscures important features.

Please help!