Items tagged with indexing

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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!

i got some trouble when i tried to build large matrix. in my case, notification error out of bound appear when looping stop at 9 from 24 repeatation. 

and this is my looping command:

the result of the script was:

now i feel so desperate so finish my final project because the error, please help me

for example

func1 := proc(system1)

for i from 1 to 100 do

solve([system1[1], system1[2]],[x,y]);

od:

end proc:

 

func1([diff(y,t) = data[i+t+1], diff(x,t) = data[i+t+1]])

i is depend on the for loop inside a function, but woud like to pass this system into a function with i

this will cause error

how to write better for passing a system as parameter using variable inside a function?

To select a piece from a list, for example:

lst:=[1,2,3,4,5,6]

I want to get the list piece from second place to fifth place: [2,3,4,5].

Is there a function?

Thanks

I am writting a program that needs to rename variables by increasing the second index of a variable, all the variables will be named y[something,number].

e.g.

y[a,2]->y[a,3]

If I was doing this outside maple I can see how I could use regular expressions, but I can't see how to do it in maple

I have the following command (credit to @Carl Love ), this command will do certain bit shifting with the next block, and the last block will shift with the first block. 

B:= Matrix([[0,0,1,1,0,0,1], [0,0,1,1,1,0,0],[0,1,0,1,0,1,0], [1,0,0,1,1,1,0]]):
Bnew:= copy(B):
Bnew[[4,1,2,3], 3..5]:= B[.., 3..5]:
Bnew; 

May i know any command can help to reverse the shifting position between the block?

for example,

original block  [0,0,1,1,0,0,1], [0,0,1,1,1,0,0],[0,1,0,1,0,1,0], [1,0,0,1,1,1,0]

i need to shift the 3..5 position of block 1 and change to the 5..3 position of block 2. 

Example:

After shifting, 

Bnew=[0,0,1,1,1,0,1],[0,0,0,1,0,0,0],[0,1,1,1,0,1,0],[1,0,0,1,1,1,0]

Any command can help to solve? thank you in advance.

So, I am working in a partial differeital equations course and we are doing image processing. I am taking an image and pixel by pixel applying the heat equation to smudge out noise. I created a for loop for the equation and it works, I need to itterate it over and over again. Here is my code:

for t from 1 to 20 do    

for j from 2 to 149 do

for k from 2 to 149 do  

`tile2__j,k`:=dellT/(h^(2))*(`tile__j+1,k`-4*`tile__j,k`+`tile__j-1,k`+`tile__j,k-1`)+`tile__j,k`  

 end do

end do  

for m from 2 to 149 do

for n from 2 to 149 do  

`tile__m,n`:= `tile2__m,n`  

end do

end do  

t := t+1  

end do

 

Sorry, I could not get the Maple Math editor to work so I just copied my code. Apologize. I keep getting the error "Error, Invalid loop statement termination." Help?

 

Ok so i have a matrix M filled with complex roots of unity. I want to execute the following code but it seems to be failing to do so correctly

t:=exp(2 Pi I/11);

m := (i, j) -> M[(i mod 11)+1, (j mod 11)+1] ;  

mu :=(i,j)->(add(add(add(a[k]*a[m]*a[n]*t^(m)*m((i+k-m),(j+n-m))),n=0..10),m=0..10),k=0..10));

 

Something is wrong with my indexing of the matrix . or when the mod procs.

Hi, the display function in the simplex package gives us a nice breakdown of the form Ax<=b, but how do we extract the individual elements, i.e. the matrix A and vectors x and b? Normal indexing into the expression doesn't work, i.e. if for some set of constraints of the form 2x+3y<=21 we enter

res:=display(constraintSet);

this gives us a nice expression, but res[1] etc. doesn't work as we might hope (i.e. by returning the matrix A).

 

Hi, i am new to Maple. I was trying to solve some problem and came up with the following difficulty:

When i give input

ai=(1+ki)/(1-ki);

 

and then do a_1 it gives the proper output as 

 

(1+k1)/(1-k1);

 

But whenever i try to do

ai,j=(ki-kj)

I often have large matrices and have to grab only every nth column or row (for plotting

for example). So far I've been doing it this way:


nthColumns:=proc(v_m, v_n)  
v_m[..,[seq(i, i=1..rtable_size(v_m)[2], v_n)]]
end;
nthRows:=proc(v_m, v_n) 
 v_m[[seq(i, i=1..rtable_size(v_m)[1], v_n)],..]
end;

A := LinearAlgebra:-RandomMatrix(20, 20, outputoptions = [datatype = float[8]]);

This does not make any sense to me :-)

restart:
A := Matrix([[seq(i, i = 1 .. 10)], [seq(i, i = 11 .. 20)], [seq(i, i = 21 .. 30)]]):
A[.. -1,..] ;
A[.. -2,..] ;



You would assume that A[..-1,..] would remove the last row but that is not the case!
Instead you have to do A[..-2,..] he he it seems a bit odd!

Hi, I am a student (with some programming background) in desperate need of help.

How can I create a zero based array in Maple and display it?

I am having all kinds of trouble creating vectors and arrays in Maple (the help is cryptic). This is the closest I got:

>F := Array(0 .. 4, 0 .. 4, [0])

 

That creates a 5x5 array of zeros, with the upper left element indexed by (0,0) (right?).

How do I display the array?

Hi

I have some difficulties in manipulating matrices in Maple

For example, I have a matrice with 40 rows and 9 columns ans I want to extract the odd rows taking columns inchanged. The new matrice which has 20 rows and 9 columns must replace the old matrice

In Matlab, I do this with only one command: WTable=WTable(1:2:40,:);

Thanks in advance for help

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