I have the following inequality system : 

              [ U_1,2 + U_1,3 -1 = 0,

U_2,3 - U_1,2 = 0, 

-U_1,3 -U_2,3+1 = 0,

0 <=U_1,2,

0 <= U_1,3,

0 <= U_2,3]

I want to solve it using LinearMultivariateSystem, namely I excuted a command : 

Then the following is return : 

Error, (in Utilities:-SimpleAnd) invalid input: a string/name list is expected for sort method `lexorder`

 I tried that

My question is that how do you use LinearMultivariateSystem for varibles indexed by two params.

Thank you.

Hiya

from this

>with(combinat):
>A:=choose([CPC__h, SIZE__h,CPC__m, SIZE__m,CPC__l, SIZE__l],2): 

where h denotes high, m=medium, l=low

I want to select CPC and SIZE all the combinations w.r.t h, m and l

[[CPC__h, SIZE__h], [CPC__h, SIZE__l], [CPC__h, SIZE__m], [CPC__l, SIZE__h], [CPC__l, SIZE__l], [CPC__l, SIZE__m], [CPC__m, SIZE__h], [CPC__m, SIZE__l], [CPC__m, SIZE__m]]

>nops(A)-3

9

I want to apply the methodology to 
choose([CPC__h, SIZE__h, SH__h,CPC__m, SIZE__m, SH__m,CPC__l, SIZE__l, SH__l],3)
 

hi , I want to solve a problem of structural analysis (slope deflection) in maple but .... ?

convert(...,Int) in Maple 2018.2 works for fourier, invfourier, laplace, but does not work for invlaplace.  

Why is that? Is there a workaround?

expr:=fourier(f(x), x, w):
convert(expr,Int);

expr:=invfourier(f(w), w, x):
convert(expr,Int);

expr:=laplace(f(s),s,t):
convert(expr,Int)

expr:=invlaplace(f(s),s,t):
convert(expr,Int)

Was expecting to see the Mellin's inverse formula.

Maple 2018.2 on windows 10

In the snip from Maple help: please expaln (a) the meaning, (b) how do I enter e1..-1,2 in the last statement?

Thanks

Hi I am trying to solve the following system of equation. I could solve it for approximate value of s(0)=0.9999 using middefer method of bvp, but as soon as I give the b.c. as s(0)=1, Maple gives me an error that there is an numeric exception. Can someone explain it what is going wrong with s(0)=1? Any sugesstion to solve the equation?
error.mw

b := 1;
r := .1;
l := 3;
a := 10; p := 1.5; ds := 100; dk := 1;

sol3 := dsolve({ds*(diff(i(x), x)) = exp(eta(x)), s(x)^3*i(x)*b*r+(1-s(x))^3*a*l*(diff(s(x), x))/s(x)^1.5 = (1-s(x))^3, diff(eta(x), x) = dk*(i(x)-1)/s(x)^p, i(0) = 0, i(1) = 1, s(0) = 1}, {eta(x), i(x), s(x)}, approxsoln = [eta(x) = .5, i(x) = .5, s(x) = 1], initmesh = 100000, type = numeric, maxmesh = 100000, range = 0 .. 1, output = listprocedure, method = bvp[middefer], abserr = 0.1e-3, adaptive = true);

Error, (in dsolve/numeric/bvp) numeric exception: division by zero

plots[odeplot](sol3, [[x, s(x)]], 0 .. 1, color = ["Green"]);

Thanks and regards,
 

 write a programe for fractional calculus and it shows subscript error plzz help me with that

Using Latest Physics updates (I am not sure when this started), pdsolve gives Error, (in PDEtools/eval/2) numeric exception: division by zero on the following problem from a HW from text book.

restart;
PackageTools:-IsPackageInstalled("Physics Updates");
                             "220"


pde:=diff(w(x,t),t)+3*t*diff(w(x,t),x)=w(x,t);
ic:=w(x,0)=f(x);
sol:=pdsolve([pde,ic],w(x,t));

Error, (in PDEtools/eval/2) numeric exception: division by zero
 

Mathematica answer btw is 

pde = D[w[x, t], t] + 3 t D[w[x, t], x] == w[x, t];
ic = w[x, 0] == f[x];
sol = Simplify[DSolve[{pde, ic}, w[x, t], {x, t}]]

This is on Maple 2018.2 on windows 10 64 bit.

Any idea what is causing this and any workaround? Do others get the same exception?

hai, 
greetings,

I require help to plot graphs by changing differernt parameters. i am enclosing my codes and sample codes,

 my_codes.mw

nanofluid_sample.mw

Thanks in advance.

Let us consider L be the following list of 6 lists of polynomials which all of their polynomials are linear combination of B=[x^2,x*y,z^2,1]. 

L:=[[a*x^2+b*x*y-1, -(a*b-b)*x*y/a-z^2+(a-1)/a, -a*c*z^2/(b*(a-1))+(b+c)/b], [a*x^2+b*x*y-1, -(a*b-b)*x*y/a-z^2+(a-1)/a, 1],

[a*x^2+b*x*y-1, -z^2+(a-1)/a, c*x*y+1], [b*x*y-1, -x^2-z^2, (b+c)/b], [-1, -x^2-z^2, c*x*y], [-1, -x^2-z^2]].

Now, I need the matrix coefficients of any member of L (please note that any matrix has 4 columns according to the list B) . Is there any command for this?

Thank you in advanced.

Ok so when a module is loaded, there is a .dll file that loads a list of symbols into maple.exe, what can be done if an error occurs for which the debugging output declares that the PDB file for the module could not be found? 

I have read that the program database file stores debugging information related to the locating symbols, how can i fix this if my computer isn't finding theres files for a list of .dll it attempts to load into maple.exe, or is there a way for which i can make these files for each corresponding module?

u(v_u)² + uvv_uu - 2vv_{u = 0}

using maple show that the ode has an eighth dimensional lie symmetry group

For some reason the Maple software is not evaluating the last bounds for a triple integral.

But the evalf command works.

I have Maple through the school where I teach math, and the IT-guy gave us Maple 2018.1 to install. 

But after a while even though I have Maple 2018.1 installed on my computer Windows 10 pc, then Maple 2018.1 surgests that I upgrade to 2018.1?? Any idea why? 

I could not find a command that splits a polynomial in parts based on leading integer coefficients, so I wrote a procedure. It works well, but I still wonder if there is no simpler way of doing this?
My aim is to investigate whether there is some way of factoring this and other polynomials.
 

kind regards,
Harry Garst
 

Download knip.mw