## Error, number of indices exceeds rank...

Hello.

I have been trying to create a code to solve a structure by using FEM, but I keep getting an error that stops me from moving on.

Everytime I run my code, Maple gives me the error in the Title of my question:
"Error, number of indices exceeds rank"

Unfortunately I can't find any help in Maplesoft support for such error, and I need immediate help for that.

Can someone help me with that? Should I post my entire code?

Thanks!

## Error: can nog save points as a float matrix...

Hi everyone,

I often get the error 'cannot save points as a float matrix' while I'm trying to plot with the spacecurve command.

loodl2 is a 4 component vector, loodl2c is the 3 component variant.

loodl2:=T1.<loodl,1>: loodl2c:=<loodl2[1], loodl2[2], loodl2[3]>
loodlpl:=spacecurve(loodl2c, k=-10..10, color=red):

also with this syntax:
loodl2c:=loodl2[1..3]

and this syntax:

l2c1:= 2*k: l2c2:=0, l2c3:=8-k:
spacecurve([l2c1, l2c2, l2c3], k=-10..10, color=red):
Warning, unable to evaluate the function to numeric values in the region; see the plotting command's help page to ensure the calling sequence is correct

It will only plot if I do this:
loodl2c:=<2*k, 0, 8-k>
Can someone help me?

## Problem with element properties...

I am trying to use the element properties Maple has in its ScientificConstants package. I am running into problems with the density of gaseous elements:

with(ScientificConstants);

Units:-UsingSystem(); # returns SI as expected

GetValue(Element('Si',density)); # returns 2329.0000 [kg/m^3] which is 2.329 g/cm^3, which is correct

GetValue(Element('H',density(gas))); # returns 88 [kg/m^3], which is incorrect.

PDG gives the density of hydrogen as 8.376E-5 g/cm^3, which is 0.08376 kg/m^3.

Even more crazy for Krypton:

GetValue(Element('Kr',density(gas))); # returns 3677.000 [kg/m^3]. Heavy little buggers, these Kypton atoms! Should be 3.486 in the same units.

What gives? Am I missing something here?

Mac Dude

## Does maple have single command to calculate square...

In matlab there is a sqrtm() command to calculate the square root of square matrices, I want to know if there is a similar command in Maple to do same thing?

## Maple use of symbols...

What is the meaning of the "0" in the series expansion

series(x/(-x2-x+1), x = 0); ( this is the Maple command)

x + x2  + 2 x3  + 3 x4 + 5 x5  + O(x6)  This is the results

This is use in Maple I've seen quite a bit for series. I assume the the series continues on. But I am not sure

Also is there any listing of what some of the symbols that maple uses???

## Specify color for output variables...

Is there a way to specify different colors for different output variables? For example, if x,y, and z appear in the entire document as variables, I want x to be red, y to be blue, and z to be green whenever an output is displayed.

Thanks

## how i can reduce the runtime of the program ?...

hi..how i can rewrite section of this code as another form i,e ''for section''

I have a lot of line as this and runnig cise is time consuming.

is there another way to write this section in order to the runtime of the program is reduced??

thanks

 > restart;
 > with(LinearAlgebra):
 > with(VectorCalculus):
 > #Digits:=5: k:=6:
 > l:=0:
 > h:=1:
 > m:=4:
 > n:=4:
 > l1:=2*h:
 > l2:=2*h:
 > N:=0.5:
 > nu:=.3:
 > E_m:=70e9:
 > E_c:=380e9:
 > rho_m:=2702:
 > rho_c:=3800:
 > lambda_m:=nu*E_m/((1+nu)*(1-2*nu)):
 > lambda_c:=nu*E_c/((1+nu)*(1-2*nu)):
 > mu_m:=E_m/(2*(1+nu)):
 > mu_c:=E_c/(2*(1+nu)):
 > with(orthopoly):
 > for i from 0 to 5 do: L(i):=sqrt((2*i+1)/2)*P(i,z): end do:
 > Z:=rho_m+(rho_c-rho_m)*((1/2)+(z/h))^N;
 (1)
 > U:=lambda_m+(lambda_c-lambda_m)*((1/2)+(z/h))^N;
 (2)
 > S:=mu_m+(mu_c-mu_m)*((1/2)+(z/h))^N;
 (3)
 > d:=Matrix([[0,0,0,0,0,0,0,0],[sqrt(3),0,0,0,0,0,0,0],[0,sqrt(15),0,0,0,0,0,0],[sqrt(7),0,sqrt(35),0,0,0,0,0],[0,sqrt(27),0,sqrt(63),0,0,0,0],[sqrt(11),0,sqrt(55),0,sqrt(99),0,0,0],[0,sqrt(39),0,sqrt(91),0,sqrt(143),0,0],[sqrt(15),0,sqrt(75),0,sqrt(135),0,sqrt(195),0]]);
 (4)
 >

 >
 (5)

## how I can dsolve this differential equation...

hi...

how I can dsolve this differential equations. parameter p is unkown.

I want to gain w(x) and u(x) and psi(x) and p.

thanks

 >
 (1)
 >
 (2)
 >
 (3)
 >
 >
 > with(PDEtools, casesplit, declare);
 (4)
 >

## how i can dsolve this differential equations........

hi...

how i can dsolve this differential equations and obtain w(x) and U(x) and phi(x) analytical or numerically?

thanks

 (1)

 (2)

 (3)

## fix error and identify any other wrong and explain...

> {w = -4*mu, a[-1] = -12*mu/(a+b), a[0] = a[0], a[1] = 0, b[-1] = 0, b[0] = 0, b[1] = 0};
/                     12 mu
{ w = -4 mu, a[-1] = - -----, a[0] = a[0], a[1] = 0, b[-1] = 0, b[0] = 0,
\                     a + b

\
b[1] = 0 }
/
> restart;
>
> w := -4*mu;
-4 mu
> a[-1] := -12*mu/(a+b);
12 mu
- -----
a + b
> a[0] := a[0];
a[0]
> a[1] := 0;
0
> b[-1] := 0;
0
> b[0] := 0;
0
> b[1] := 0;
0
> xi := x+w*t;
x - 4 mu t
> P := sqrt(mu)*tan(A-sqrt(mu)*xi);
(1/2)    /      (1/2)             \
mu      tan\A - mu      (x - 4 mu t)/
> u := a[0]+a[1]*P/(1+lambda*P)+a[-1]*(1+lambda*P)/P+b[0]*sqrt(sigma*(1+P^2/mu))/P+b[1]*sqrt(sigma*(1+P^2/mu))+b[-1]*sqrt(sigma*(1+P^2/mu))/P^2;
(1/2) /             (1/2)    /      (1/2)             \\
12 mu      \1 + lambda mu      tan\A - mu      (x - 4 mu t)//
a[0] - -------------------------------------------------------------
/      (1/2)             \
(a + b) tan\A - mu      (x - 4 mu t)/
> Diff(u, x, t)+a*(Diff(u, x))*(Diff(u, x, y))+b*(Diff(u, `\$`(x, 2)))*(Diff(u, y))+Diff(u, `\$`(x, 3), y);
/   2   /            (1/2) /             (1/2)    /      (1/2)             \\\
|  d    |       12 mu      \1 + lambda mu      tan\A - mu      (x - 4 mu t)//|
|------ |a[0] - -------------------------------------------------------------|
| dt dx |                              /      (1/2)             \            |
\       \                   (a + b) tan\A - mu      (x - 4 mu t)/            /

\     /    /
|     | d  |
| + a |--- |a[0]
|     | dx |
/     \    \

(1/2) /             (1/2)    /      (1/2)             \\\\ /   2   /
12 mu      \1 + lambda mu      tan\A - mu      (x - 4 mu t)//|| |  d    |
- -------------------------------------------------------------|| |------ |
/      (1/2)             \            || | dy dx |
(a + b) tan\A - mu      (x - 4 mu t)/            // \       \

(1/2) /             (1/2)    /      (1/2)             \\\\     /
12 mu      \1 + lambda mu      tan\A - mu      (x - 4 mu t)//||     |
a[0] - -------------------------------------------------------------|| + b |
/      (1/2)             \            ||     |
(a + b) tan\A - mu      (x - 4 mu t)/            //     \

2 /            (1/2) /             (1/2)    /      (1/2)             \\\\ /
d  |       12 mu      \1 + lambda mu      tan\A - mu      (x - 4 mu t)//|| |
-- |a[0] - -------------------------------------------------------------|| |
|                              /      (1/2)             \            || |
\                   (a + b) tan\A - mu      (x - 4 mu t)/            // \

/            (1/2) /             (1/2)    /      (1/2)             \\\\
d  |       12 mu      \1 + lambda mu      tan\A - mu      (x - 4 mu t)//||
--- |a[0] - -------------------------------------------------------------||
dy |                              /      (1/2)             \            ||
\                   (a + b) tan\A - mu      (x - 4 mu t)/            //

/ 4 /            (1/2) /             (1/2)    /      (1/2)             \\
|d  |       12 mu      \1 + lambda mu      tan\A - mu      (x - 4 mu t)//
+ |-- |a[0] - -------------------------------------------------------------
|   |                              /      (1/2)             \
\   \                   (a + b) tan\A - mu      (x - 4 mu t)/

\\
||
||
||
//
> value(%);
/                                 2\
3        |       /      (1/2)             \ |
96 mu  lambda \1 + tan\A - mu      (x - 4 mu t)/ /
--------------------------------------------------
a + b

2
/                                 2\
3        |       /      (1/2)             \ |
96 mu  lambda \1 + tan\A - mu      (x - 4 mu t)/ /
- --------------------------------------------------- +
2
/      (1/2)             \
(a + b) tan\A - mu      (x - 4 mu t)/

/
|
1                    |     (5/2) /
-------------------------------------- \96 mu      \1
3
/      (1/2)             \
(a + b) tan\A - mu      (x - 4 mu t)/

(1/2)    /      (1/2)             \\
+ lambda mu      tan\A - mu      (x - 4 mu t)//

2\
/                                 2\ |
|       /      (1/2)             \ | |
\1 + tan\A - mu      (x - 4 mu t)/ / / -

/
1                   |     (5/2) /
------------------------------------- \96 mu      \1
/      (1/2)             \
(a + b) tan\A - mu      (x - 4 mu t)/

/
(1/2)    /      (1/2)             \\ |
+ lambda mu      tan\A - mu      (x - 4 mu t)// \1

2\\
/      (1/2)             \ ||
+ tan\A - mu      (x - 4 mu t)/ //
> simplify(%);
Error, (in simplify/tools/_zn) too many levels of recursion
>

## plot an indefinite integral ...

hi every one, i want to plot an indefinite integral  , it is some what complex and maple can not compute the answer, ( but numeric integration can be computed) , but we want to plot the output, what should we do ? tnx for help in advance

corrected.mw

## weighted norm of an expression...

how can we compute wighted norm of a matrix or a vector in maple?

## How can I convert a result to a trigonometric iden...

How can I convert the result (2) to equal to the trigonometric identity (kw/s^2)*tanh(a*s/2)?

 >
 (1)
 >
 (2)
 >

## how to dsolve for this equation?...

this equation is complicated

how to dsolve for this equation for function f ?

f(t,x,diff(x,t)) - f(t,x,p) - (diff(x,t)-p)*diff(f(t,x,p), p) = tan(t)