Hi!
I have an external library with this function:
```
double test(double x)
{
return sin(x);
}
```

In Maple I am doing this:
**test := define_external('test', x::(float[8]), RETURN::(float[8]), LIB = "Test.dylib");
f := x->test(x);
**
Now when I call f(2) for example, I get 0.909297426825681710 back.
But if I try this:
**plot(f(y), y = 0 .. 2);**
I get this error message:
`Error, (in f) invalid input: test expects its 1st argument, x, to be of type numeric, but received y`

I think I need to somehow convert the (possible) symbolic input of f into a float[8] before it is passed to the procedure test, but I can't figure it out.

Maple Professionals:
I wish to import a file with float type values which is 338*16 big. I saved it in Excel as a .csv type file. Using the Import Assistant works. However I don´t want to use the assisstant everya time I run my calculations. Thus I tried to use the commands readdata(), ImportMatrix(). Hoever non of those do like me :-(. I am really frustrated.
I attempted the following commands, having already converted the csv into a txt:
> lambda:=ImportMatrix("D:\01_1_CSML DATA\Prognose & Bestände\04_2.txt",datatype=anything);
Error, (in ImportMatrix) file or directory does not exist

Hello all.
I am have recently gotten help in here, where it was suggested to me that i used Liblip to interpolate my 3d datasets. This has worked fine after i figured out how to make it work. I have however now encountered a problem with the LipIntSmoothLipschitz command, where on the latest dataset i am running, it makes a memory drain which ultimately after a long data accumulation, results in Kernel connection loss. I hope someone has an idea of what is wrong.
My loaded data is assigned like this:
First line: 2 (number of dimensions), 1852 (number of lines)
Second line and below: X Y Z (In first part sorted by increasin Y)
Here is my setup (Have made notes in, and at the bottom of worksheet):

Suppose I generate a PLOT3D structure by
p:= plot3d(f(x,y),x=-1..1,y=-1..1,grid=[3,3]):
p2 := convert( p, POLYGONS );
Now I want to go through these polygons and throw away those that have a vertex far away from the origin (say more than 10 units), and then redisplay the trimmed structure.
Is there a snazzy way to do this?

Maple needs commands to interpolate and plot large data sets. Consider the following:

# generate data
data := convert(LinearAlgebra[RandomMatrix](10000,2,generator=-100000..100000),listlist):
data := sort(map([op], [op(op(table(map(`=`@op, data))))]), (a,b)->evalb(a[1] < b[1])):
data := Matrix(map(proc(a) [a[1],a[2]/200.] end,data), datatype=float[8]):
# now suppose I take this data and...
f := CurveFitting[BSplineCurve](data, x);
plot(f, 0..100);

Someone trying to do this with real data (and 10000 points is small) will experience the following problems:

1. When Maple exports its worksheet to LaTeX, it converts each plot to an .eps file with /drawborder set to true in the .eps file as a default. I have found no information or a preference in Maple 10 that would allow me to change that default to false. Is there a way to change that default in Maple to false? If not, is there a way in a TeX file later to change that switch to false so that .eps figures drawn with \includegraphics command would appear without a border? I know I can open any .eps file in say MS Notepad and manually edit the line /drawborder true to /drawborder false, but I am looking for a smarter way to do that.

I am using Maple to solve some inequalities where the solution I get is a RealRange or a real constant. And I want to get an union of these values. I wrote a short procedure which does the work. But is there a better way to do this (there must be :-) )?
```
> RealRangeUnion:=proc(L::list) local L2, rel, rel2, eq, sol, x;
> assume(x, real);
> L2:=map(a->`if`(a::realcons, x = a, x in a), L);
> rel:=convert(L2, relation);
> rel2:=convert(Or(op(rel)), relation);
> eq:=piecewise(rel2,1,0);
> sol:=solve(1=eq,x);
> RETURN(sol);
> end proc:
>
> L:=[RealRange(Open(-2),-1), RealRange(Open(0),1), RealRange(1/2,2), -3, -2];
```

I know I have done this before, but I'm not having any luck today.
I am using Maple 10.
I want to check if a user-entered function is positive for values in a bounded or unbounded interval. I do not want to do too much that is fancy, just functions that are likely to show up in the integral test for convergence of a series.
Specific question: How can I get Maple to report that 1/sqrt(k) is decreasing for all k>1?
I have tried working with both sqrt and surd, and with various assumptions. But, nothing gives a useful result.

f := 1/sqrt(k); # no information
solve( diff(f,k)

Greetings. As mentioned in earlier posts, I often find the answer given to a question regarding the use of the 'sum' command as: don't use 'sum', use 'add', and all will be fine. I agree, and I use the add command for adding numbers together. But, if all I am doing is adding numbers together, from a sequence and nothing else, why not use the 'sum' command. It seems to be orders of magnitude faster than the 'add' command if there are a large number of numbers(I have no metric for what large is as far as numbers go). As an example, I execute the code below and look at the results.
> restart:

I am using the latex2edu conversion service at
qa.brownstone.net/latex2edu
to convert latex files into MapleTA questions.
However, for the last 4 days this service has not been available.
Mail to support@brownstone.net and my local MapleSoft representative has not been answered.
Has anyone else experienced this problem?
Does anyone know whether the service is available elsewhere?
Arne Jensen
Aalborg University
Denmark

Hi,

we've been happily using Brownstone's latex -> edu conversion service for some time now, but always with that slightly queasy feeling of "what happens if it's unavailable?". Well that's the case at the moment: I've submitted a ticket with their support folk, but times in Australia don't match up well with US times! In the meantime we have a number of assignments due to be made available to students, but which only exist as latex files. Conversion by hand is, to say the least, painful and time consuming (our Level I coordinator has already converted two by hand, and doesn't need another few hours of such nonsense), so I'm hoping that there may be another way in which this can be done. Any suggestions?

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]]);
```

Would anyone be able to help me integrate ones like the following:
Int(1/exp(eta)*eta*hypergeom([1, 1, 1],[2, 2, 2],eta),eta);
I've tried using convert, simplify, etc. but nothing works.
Many thanks,
Sandra

I used Maple10 to solve an ODE from my research project and got a solution with HeunC function. I did derivative of the HeunC function and got HeunCPrime function. However I found HeunCPrime is just a sign. It cannot be valued or plotted with a selection of parameters. My questions are as follows:
1. Is there any special package I need to use to value or plot HeunCPrime function?
2. Is it possible to convert HeunC into other functions which I can manipulate for derivative and plotting?

Hi,
I've been experimenting with the quaternionspackage. (The free download, not the commercial package). There seems to be an error in the calculation of the inverse:
with (Quaternions);
[*, +, -, Qabs, Qadd, Qamplitude, Qangle, Qarccos, Qarccosh, Qarccot,
Qarccoth, Qarccsc, Qarccsch, Qarcsec, Qarcsech, Qarcsin, Qarcsinh, Qarctan,
Qarctanh, Qargument, Qaxial, Qceil, Qcolatitude, Qconjugate, QconvertToFrac,
Qcos, Qcosh, Qcot, Qcoth, Qcsc, Qcsch, Qdefine, QdivLeft, QdivRight, Qdot,
Qeval, Qexp, Qfloor, Qfrac, Qicoeff, Qinverse, QisCommutable, QisEqual,
QisPure, QisScalar, Qjcoeff, Qkcoeff, Qlength, Qln, Qlongitude, Qmagnitude,