One of those vexing things that should be easy:

I am reading in a data file using ImportMatrix. Since the file has one column with texual data I cannot use datatype=float since that bombs. I >can< ImportMatrix with datatype=string or anything.

I then extract columns using the appropriate command and want to do something numeric with them (only with those columns that have correct floating point numbers). That fails since my data are now not floats (even when using anything...

i have an ode,which its derivatives are with respect to time,i want to use the output as a function of time to use it in a loop ,what should i do ?!

A:=a*diff(x(t),t,t)+b*diff(x(t),t)+c*x(t);

B:=solve(A,diff(x(t),t,t));

at first how can i define B as a function of t here?
how can i define initial conditons for this ?
for example :
a0:=diff(x(t),t,t) at time 0 (x(0)), but i do not know how to define this?

i also can not use B in a loop of time,t

Hi,
How do I complete the integral below? I'm not sure what the resulting function looks like, but it will be a function of n where epsilon is a real constant. My ultimate goal is to graph the resulting function where epsilon is equal to -0.4.

Thank you.

Hi, 

in my programm I've got a maplet with 6 CheckBoxes, but I can't manage to get the true/false-values in a list to use them. I think I should define a list, I tried:

BoxRow(...

   GridLayout([

      [CheckBox['CB1](), "Box1"],

      ....for all 6 boxes...

])),

lstW:=['CB1','CB2',...for all 6 boxes];

But all I get is: Error, `:=`unexpected. 

Hello!

I have encountered a bizarre problem while trying to collect data from SQL table. Command

c:-ExecuteQuery(" SELECT QUERY HERE", 'output' = 'Array')

takes quite long time to execute. The data that I am trying to collect is not a big array (like 100x100). I have these felling that Maple cannot collect whole table at once. Command:

c:-ExecuteQuery("SELECT QUERY HERE", 'output' = 'result')

is immediate so it is not a problem of slow...

I have to vary two variables A & B. For a fixed A, if I vary B such that l1 and l2 is positive, then I need the min value of B for which ((l1>0) and (l2>0)) 

. In such a way I need the list of A & B.

restart; printlevel := 0 

for A  from .1 by .01 to 3 do  
 for B  from .1 by .01 to 3 do
l1:=(exp(B)-A)-1
l2:=(exp(B)-A/2)-1.5

end do

if ((l1>0) and (l2>0)) then print(A,min(B)) end if

im interested to know if there are developed MapleSim examples of water level control in a tank

I am dealing with Fourier series, I have series of sin(nw) + cos (nw) for different  value of n . How can I put all sin together and all cos together equal to zero, when n=1000 for example.

hi

I have an unkhown function as f(r) which i want to solve it at the end of calculation. How can i define it in beggining?

I created a Maplet that calculates ODE (Ordinary Differential Equations) however I would like to create a button that can allow printing on paper

i confused for finding a very special command that can join a "set of values" to a "set of indices " ?

also i can't use the map command for this ( guide ? )

like this :

{(1,1),(1,2),(2,1),(2,2)}

{1,2,3,4}

i want to join the two sets to form a complet set of equations index :

{(1,1)=1,(1,2)=2,(2,1)=3,(2,2)=4}

since this is just a simple example , but i need an efficent way for doing it in large size data (image processing)

appreciate for answering !

hey friends I have solved linear equation numerically and in the end i have ploted pointplot graph where every point in graph is taken maunally. Please help me how to write code that at specific values of x required points from 

Solution := backsub(S) 

should automatically be ploted where x=i*h and h=1/32 where i varies from 0 to m. 

For example, fill in the follwing blanks with 1~9 numbers to make it as an identity, the numbers are MutuallyExclusive.
()/()+()/()+()/()+()/()=()
Thank you very much for any method.

Please could you please help me finding closed expression for the following double integral

restart;

with(LinearAlgebra);

rho := .25; sigma := .1; SNR := 25;                                                                    

 a := (32*12)*Pi*sqrt(1-rho^2...

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

When i give input

a_i=(1+k_i)/(1-k_i);

and then do a_1 it gives the proper output as 

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

But whenever i try to do

a_i,j=(k_i-k_j)