Simplest example I can think of.
I want to define f(x) to be the absolute value function
(yes, of course, without using the built-in Maple absolute value
function)
f:=x->x;
is great for defining a function. I've used that many times to
define n-vector-valued functions of m variables.
But how do I do
f:=x->x if x>0
f:=x->-x if x

Hi,
I have a modeling equation and a set of data points, and I want to compute the accuracy of my equation relative to the data points. Is there anyway to compute the R squared value of my equation relative to these data points? All of the commands I can find in Statistics are used to *fit* an equation to the data points, which I don't want to do, I just want to have a qualitative measurement of how accurate my equation is.

How is it possible that the following program works correctly:
printlevel:=2:
for n from 1 to 10 do
if (0=0 mod 5) then 0;
end if;
end do;
It correctly outputs ten 0's.
But, when I change 0 to n inside the if conditional
printlevel:=2:
for n from 1 to 10 do
if (n=0 mod 5) then 0;
end if;
end do;
I get nothing for output. I should get two 0's.
n is 0 mod 5 exactly twice as n runs from 1 through 10.
I have experimented with adding spaces and deleting spaces
between keywords and parentheses and numerical values
to test if that was the problem. Nothing works.

Dear Sir/Madam,
I have written a small program to calculation a kind of integration. This integral depends on the values of another function which is given numerically. I want to calculate numerical results of this integral. But the I just have sucu result as "Float (Undefined)" . Please help me to find where is wrong. Thank you very much!

Download 7745_Float undefined.mwsView file details
In this Maple 10 classic worksheet I'm trying to get the eigenvalues of the matrix H, which are dependent of the parameter

F>=0.
Please help me to get rid of those RootOf's. The result may be numeric because I only need it for plotting.

Download 5085_20_H.mwsView file details
Hi Guys i have 2 matrices, A and B, a[i,j] and b[i,j] are the elements of the matrices respectively. How can i set the entries of A to equal the entrices of B, so then when i use the command, evalm(A), the previous a[i,j] values will become b[i,j]? Thanks.

for n from 1 to 2
do
if(isprime(L[n]) then 7
else 9;
end if;
end do;
No matter combination of semicolons or colons I put
at the end of each line or omit,
I cannot get this little test routine not to spit
back "unable to match delimiters" error message.
L := [4, 5];
P1 := [-8, 9];
if (5 > 6) then P1[1]
else L[2];
end if;
Ironically, this routine worked. I do not see the difference.

The equation y'= ((2-t)(2-y))/y , y(0)=1
How do I use Euler's method to calculate an approximation to y(1) using step size
i. h=0.2 ii. h=0.1 iii. 0.05

I am new to Maple (I have Maple 11 student version)
I tried to simplify atan(tan(x)) and nothing happens
Also atan(sin(x)/cos(x)) does not simplify.
What is the trick to simplification?

Dear all:
Inside maple, I want to call C program which is compiled using cygwin & gcc. I did a very easy one for testing.
int _stdcall add( int num1, int num2 )
{
return num1+num2;
}
and then gcc -o add.c && gcc -shared -o add.dll add.o
However, this doesn't work. Maple continue to load the DLL forever......
Does anyone know the reason?
I did it with Visual C++ with VC specific options and it works just fine.
Thanks,
Peter

the equation y'=1-y(t)^2
how do you construct the de plot and find the equilibrium solutions

I want to have a solve command in a loop like this:
for j from 0 to 10 do s[j]:=solve( {f[j]=0 , g[j]=0},[ a[j] , b[j] ]); od;
where f[j] and g[j] are complex exponential functions of j and a[j]& b[j] e.g in a very simple case:
f[j]:=a[j]*exp(I*2*j)+b[j]
after such a loop Maple just solve s[0] and for other j's a warning message appears saying: "solutions may have been lost". And amazingly this warning seems very correct for when I put the solve command outside the loop,like
solve({f[2]=0,g[2]=0},[a[2],b[2]]);
it simply solves it!
I don't know how I can overcome this problem?!

Hello,
first post here, thanks for letting me on the forum.
I am trying to visualize fourier approximation. This means that I want an animation of the several functions I get (the first only uses cos(x) and sin(x), the second one also uses cos(2*x) and sin(2*x)...)
I managed to do this:
[quote]
restart;with(plots):f:=piecewise(-Pi

When you call call_external like call_external(p1,p2,p3,p4) what do the four parameters mean?

Hi guys, do any of you know how to differentiate a matrix, i have the command
A:=Matrix(2,2,symbol=k):
I want to treat the elements k[1,1]..k[2,2] as variables, and then differentiate the matrix
with respect to say k[1,1], and so on. How can i do this?