## compute integral...

Can someone answer why i get Float(undefined) while computing integral

Here is my example

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## query "undefined" specifics...

when a term in the evaluation of some calculus functions particularly, i sometimes arrive at output in the general form as follows:

Algebraic expression + undefined

i am just wondering if there is a function i can call that will return the specific details as to what error the term "undefined" placeholder has stored im assuming such information is held, ie is it undefined as a consequence of the limits either side not being equal to one another or is it a 0/0 evaluation.

## How to specify undefined value for part of a piece...

Having a function where the value is for example only defined when abs(x) <= 1, then how can I specify that the value is otherwise undefined, the replacing "How_to_specify_undefined_value" below?

## Float(undefined) as integral value...

hi.i am a problem with calculate numeric integral.

thanks

## Derivative of Spline at the nodes...

Hi!

This question is related to http://www.mapleprimes.com/questions/204419-Derivatives-Of-Splines-Are-Not-Defined and http://www.mapleprimes.com/questions/42114-Problem-With-Spline-Integrating , however I have not been able to apply the solutions given there to my problem.

I have a set of points given by

and certain function value points given by

where e1 is the function I am approximating.

Using

I come up with my piecewise function.

When I do diff(e4,x), however, the points at the nodes show "float(undefined) x=0.2..."(the node).

As it turns out, the value of the derivative on the left of the node is not equal to that of the right side by a factor of 10^(-7), in other words, numerically unimportant but high enough for maple to realise it is not the same number. How could I tell Maple that I am happy choosing, for example, the value given by the function on right side of the node?

I welcome any suggestions.

## Derivatives of Splines are not defined on some poi...

Hello everyone,

I have a question regarding my Spline interpolations. I am not an expert on the theory there, but the maple help tells me that the first derivative of an 3rd degree spline interpolation should exist at the knots. But a derivation returns "undefined" at some of the knots instead. Here is my example:

x(t):=Spline([[0, 0], [1, 1], [2, 2], [3, 2.2], [4, 1.8]],t,degree=3);

returns

x(t):=piecewise(t < 1, .953571428571429*t+0.464285714285714e-1*t^3, t < 2, -0.9286e-1+1.09285714285714*t+.139285714285714*(t-1)^2-.232142857142857*(t-1)^3, t < 3, .65000+.675000000000000*t-.557142857142857*(t-2)^2+0.821428571428571e-1*(t-2)^3, 2.77857-.192857142857143*t-.310714285714286*(t-3)^2+.103571428571429*(t-3)^3);

diff(x(t),t);

returns

piecewise(t < 1., .953571+.139286*t^2, t = 1., Float(undefined), t < 2., .814286+.278571*t-.696429*(t-1.)^2, t = 2., Float(undefined), t <= 3., 2.90357-1.11429*t+.246429*(t-2.)^2, 3. < t, 1.67143-.621429*t+.310714*(t-3.)^2);

Not defined at t=1 and t=2. Is it possible to get an interpolation of which the first derivative exists at every point? Thank you very much!

## Angle input in Maple 16 and in Maple Calculator...

Hello!

I'm pretty new to Maple and I can't figure out how to input angles in degrees and radians in Maple 16 and in Maple Calculator.

E.g. How could I type 58 degrees, 28 minutes, 18 seconds?

puckie62

## Force execution on loop (and seq)...

Say for a complicated function f(x), there are 10 solutions. I want to check for any of the solutions, the matrix R is defined or not.

Is there a way to force execution like the following ones?

seq(1/i,i=0..3);

for i from 0 to 3 do
1/i;
end do;

I think the problem is that, Maple stops immediately when it's undefined. But the following terms could be defined.

Or is there a way to put this check into "solve"? That's

> solve(f(x),x, "some way of making sure that the solution has to be defined for the matrix R" )

Is there a way to achieve this?

Thanks

## Error Invalid If Statement...

I keep getting an error about the while. It is calling it an invalid if statement.  It may relate to semi colons, but I cannot find any errors myself. Please help.

InterpolIDW2:=proc(n,rwin,mink,p,R,IR)

local ix,iy,i,j,i0,i1,j0,j1,k;

local count,wgt,top,bot,hp;

print(`n=`,n,`rwin=`,rwin,`mink=`,mink,`p=`,p);

hp:=p/2;

for iy from 1 to n do

for ix from 1 to n do

if (IR(ix,iy)=0) then

i0:=max(1,ix-rwin);  i1:=min(n,ix+rwin);

j0:=max(1,iy-rwin);  j1:=min(n,iy+rwin);

while (k<mink )do

if(i0>1) then

i0:= i0-1;

end if;

if(i0<1) then

i0:=i0+1;

end if;

if(j0>1) then

j0:=j0-1;

end if;

if(j0<1) then

j0:= j0+1;

end if;

end do;

top:=0;  bot:=0;

for j from j0 to j1 do

for i from i0 to i1 do

if (IR(i,j)<>0) then

wgt:=1/evalf[14](((ix-i)^(2)+(iy-j)^(2))^(hp));

top:=top+wgt*R(i,j);

bot:=bot+wgt;

end if;

end do;

end do;

R(ix,iy):=top/bot;

end if;

end do;

end do;

end proc:

## Pde system with initial condition...

Dear Maple Users,

I'm beginner in Maple.

I have this system of Pde:

with lambda experimental parameter and n,c,v dependent variables. I write this on Maple but I read on internet that the solution "float(undefined)" is an error.

I will insert this initial condition: c(x,0)=0,n(x,0)=0.4

Thanks everybody

## esc + esc + enter breaks Maple

Maple

Just came across this

Press esc twice then enter.  Maple becomes unresponsive.

## Sqlite Connector...

Hi, again:

Is there a way to connect Maple with Sqlite?

C.L.

## How do I graph a solution curve in the phase plane...

I am dealing with second order linear differeantial equations for RLC and forced RLC circiuts.

I am having trouble with plotting a solution curve in the phase plane.

> restart;

with(plots); with(DEtools);

L := 10; R := 20; C := 1/100;

de1 := diff(x(t), t) = y(t);

de2 := L*(diff(y(t), t))+R*y(t)+x(t)/C = 0;

DEplot({de1, de2}, [x(t), y(t)], t = 0 .. 5, [[x(0) = 10, y(0) = 0]], stepsize = 0.5,