## How to evaluate this double integral?...

hi! Could somebody tell me how to evaluate this double integral in Maple int(int(A*sin(2*Pi*B*(alpha-beta))/(Pi*(alpha-beta)),beta=-T/2..T/2),alpha=-T/2..T/2) Thanks, Raj

## Very slow evaluating matrix computation.

by: Maple
Hello, I would like to use Maple instead of Matlab, well I rewrite the Matlab code to Maple like following. The output is correct, but it spends more time than in Matlab. Is it possible to rewrite my Maple code to get output faster? ```restart: linearni_model:=proc(beta,sigma) local n1,n2,Y,X,Y1,Y2,se,se2,t1,t2,t3,t4,vbeta,t,si2,e1,e2,e3,e4,Yp,N,s2,n; use Statistics in X:=Matrix([[1, 1, 1, 1, 1], [1, 1, 1, 1, -1], [1, 1, 1, -1, 1], [1, 1, 1, -1, -1], [1, 1, -1, 1, 1], [1, 1, -1, 1, -1], [1, 1, -1, -1, 1], [1, 1, -1, -1, -1], [1, -1, 1, 1, 1], [1, -1, 1, 1, -1], [1, -1, 1, -1, 1], [1, -1, 1, -1, -1], [1, -1, -1, 1, 1], [1, -1, -1, 1, -1], [1, -1, -1, -1, 1], [1, -1, -1, -1, -1]]); ```

## How could I do sumation of members of 1st column...

by: Maple
Hello, I would like to use sum command to compute sum. ```> A := Matrix(3, 2, {(1, 1) = 1, (1, 2) = 2, (2, 1) = 2, (2, 2) = 3, (3, 1) = 3, (3, 2) = 4}); > sum(A[k, 1], k = 1 .. 3);``` Error, bad index into Matrix Why it occures an error? If I use sum over list, it works. How can I sum members of 1st column of Matrix? Thanks Vladimir

## summation piecewise...

I'm an older adult, getting back into math and realizing how much I've forgotten. Likewise, I'm new to maple and just made a discover. Anyhow, I'm wondering if I'm looking at this correctly. The following: sum(piecewise(n <>

Hi, I am trying to add some useful inverse Laplace transforms to Maple's integral tables. I am frustrated that these transforms will only be recognized subsequently if they are entered in exactly the same format. For example, if I type: invlaplace(exp(-p*sqrt(s)/s),s,t); I get: invlaplace(exp(-p/s^(1/2)),s,t) but if I add this transform to the table: addtable(invlaplace,exp(-p*sqrt(s)/s),erfc(p/(2*sqrt(t))),s,t); then I get: invlaplace(exp(-p*sqrt(s)/s),s,t); erfc(1/2*p/t^(1/2)) However, if I change the p to an alpha: invlaplace(exp(-alpha*sqrt(s)/s),s,t);

## Modelling Share Prices as a Random Walk...

Hi, I'm currently investigating whether share prices can be successfully be modelled as a random walk and as part of this wish to include a program to generate such walks using maple. I've already been able to produce a program (with some help) where the output is a simple ramdom walk. The inputs I had were the starting value of the walk, the probability of an increase ( where 1 minus this is the prob. of a decrease). how much to increase by at end stage. Only now I've done some research and found that there are two potentially ways of how share price are distributed either normally, or by a scaled t-distribution. Any ideas of how to implement these? Any help is greatly appreciated.

## Maplet window selection button...

Hi, I was trying to create a window selection button in a Maplet reading the values from two radio buttons with a procedure and use the procedure output inside a runwindow command, but it´s fail. Can anyone help me? Here is the code with 3 diferent options that I try. > restart; > with(Maplets[Elements]): > with(Maplets[Elements]): > selection:=proc(test1,test2) > global procout; > if (teste1='true')then > procout='W2' > elif (teste2='true') then > procout='W3' > end if; > print(procout) > end proc: > maplet := Maplet('onstartup' = 'A1', > Window['W1']('title' = "Window Selection Button", 'layout' = 'BL0'),

## Symbol table used with an Array of Records...

I'm still making the transition from VB thinking to MAPLE thinking. In VB I delcared an 9 x 9 array of type square, where square was defined by Private Type square NumPossible As Integer Possible(9) As Boolean Number As Integer End Type I am trying to do the same thing in MAPLE with the code below. Since MAPLE is more flexible than VB, a certain possibility occured to me. With the code I have written below, does MAPLE have to store in its symbol table at run time 81 copies of the symbols 'Number', 'Possible' and 'NumPossible' ? Square:=Array(1..9,1..9); InitializeArray := proc ()

## Factor completely: x^2 - 2x^2 - 4x - 8...

I'm not sure where to start on this problem. Can anyone help?

## supplying boundery conditions for differential equ...

Hi. >sol2:=dsolve( {diff(c(x),x,x)=c(x) , c(0)=5, int(c(x),x=0..1)=3 },c(x)); Error, (in PDEtools/sdsolve) the input system cannot contain equations in the arbitrary parameters alone; found equation: _F1[x]-3 this is a DE of second order, so it requires two conditions to find the constants.. I wanted to give one of the conditions in the form of an integral, but i get the error above. Any idea why? thanks

## Can't understand the output...

I wonder if someone would be kind enough to explain the output I am getting in the simple attached file. I understand the array that is being output - that is what I want. But why the 9 below it, and the pair 'true,true' near the bottom? -Thanks View 2292_IncrementGroup.mw on MapleNet or Download 2292_IncrementGroup.mw
View file details

## Not equal to or greater than?...

Hello peeps, In some of my calculations, I need to find and answer that is greater than or not equal to a certain value.... for example differentiate a function which gives x=-2 & x=3, if I now wish to define has to be x>0, how would I incorporate that into my maple command? Thanks in advance