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the trouble with mex c

P: n/a
Hi,

sorry if this message gets posted twice, i seem to have some problem posting
to newsgroups.

i've rewritten some loop in matlab using the mex interface method in c, and
i've achieved a reduction in calculation time of about five hours :).
however, the resulting arrays
are not the same as with matlab. this is the first time i write something in
c, and i suspect i'm making some
mistakes that causes memory regions to be overwritten, pointers to be
misused, that sort of thing that
doesn't make the lcc compiler shipped with matlab complain. i've got no
debugger and after rereading c and
mex documentation i've got no clue what to do. would someone care to take a
glance at the code
and maybe identify some beginners mistake that causes the erroneous results?
I can send the code
as an attachment.

I would greatly appreciate that,

Martijn

Nov 14 '05 #1
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13 Replies


P: n/a
"Martijn van den Branden" <m.*************@student.tudelft.nl> wrote in
message news:bv**********@news.tudelft.nl...
Hi, <snip> would someone care to take a glance at the code
and maybe identify some beginners mistake that causes the erroneous results? I can send the code
as an attachment.


Don't send in an attachment, trim it down to a reasonable size (no more than
a few KB, but take care not to cut out the bits that show the problem) and
post it here.

Peter
Nov 14 '05 #2

P: n/a
I've included the full code below, but at places i've deleted declarations
of variables
where they are obvious replaced by ...

Thanks in advance,

Martijn

__________________________________________________ __________________________
#include "mex.h"
#include <math.h>
#define PI 3.14159

void source (double x, double y, double z, double x1, double y1, double z1,
double x2, double y2, double z2, double x3, double y3, double
z3,
double x4, double y4, double z4, double *srcphi, double
*dblphi)
{

ALL DECLARATIONS OF THE LOCAL VARIABLES IN THE
EQUATIONS BELOW GO HERE.

*(srcphi) = -1.0/(4*PI)*(
(
(((x-x1)*(y2-y1)-(y-y1)*(x2-x1))/d12)*log((r1+r2+d12)/(r1+r2-d12)) +
(((x-x2)*(y3-y2)-(y-y2)*(x3-x2))/d23)*log((r2+r3+d23)/(r2+r3-d23)) +
(((x-x3)*(y4-y3)-(y-y3)*(x4-x3))/d34)*log((r3+r4+d34)/(r3+r4-d34)) +
(((x-x4)*(y1-y4)-(y-y4)*(x1-x4))/d41)*log((r4+r1+d41)/(r4+r1-d41))
)
+fabs(z)*(
atan((m12*e1-h1)/(z*r1)) - atan((m12*e2-h2)/(z*r2)) +
atan((m23*e2-h2)/(z*r2)) - atan((m23*e3-h3)/(z*r3)) +
atan((m34*e3-h3)/(z*r3)) - atan((m34*e4-h4)/(z*r4)) +
atan((m41*e4-h4)/(z*r4)) - atan((m41*e1-h1)/(z*r1))
)
);

*(dblphi) = -1.0/(4*PI)*(
atan((m12*e1-h1)/(z*r1)) - atan((m12*e2-h2)/(z*r2))
+ atan((m23*e2-h2)/(z*r2)) - atan((m23*e3-h3)/(z*r3))
+ atan((m34*e3-h3)/(z*r3)) - atan((m34*e4-h4)/(z*r4))
+ atan((m41*e4-h4)/(z*r4)) - atan((m41*e1-h1)/(z*r1)));

return;
}


void coefficientmatrix(int totpanelsf, int totpanelswake, double eps,
double *xcf, double *ycf, double *zcf,
double *x1f, double *y1f, double *z1f,
double *x2f, double *y2f, double *z2f,
...
...
double *xe2wake, double *ye2wake, double
*ze2wake,
double *xe3wake, double *ye3wake, double
*ze3wake,
double *z1wakeqs, double *z2wakeqs, double
*z3wakeqs, double *z4wakeqs,
double *A, double *S, double *E)
{
int i,j,k,count = 0,count2=0;
double xp, yp, zp;
double pcolloc[3], p1[3], p2[3], p3[3], p4[3];
double srcphi, dblphi;

for(i=0;i<totpanelsf;i++)
{

xp = xcf[i]-nxf[i]*eps;
yp = ycf[i]-nyf[i]*eps;
zp = zcf[i]-nzf[i]*eps;

for (j=0;j<totpanelsf;j++)
{

pcolloc[0] = xe1[j]*(xp-xcf[j])+ye1[j]*(yp-ycf[j])+ze1[j]*(zp-zcf[j]);
pcolloc[1] = xe2[j]*(xp-xcf[j])+ye2[j]*(yp-ycf[j])+ze2[j]*(zp-zcf[j]);
pcolloc[2] = nxf[j]*(xp-xcf[j])+nyf[j]*(yp-ycf[j])+nzf[j]*(zp-zcf[j]);

p1[0] =
xe1[j]*(x1f[j]-xcf[j])+ye1[j]*(y1f[j]-ycf[j])+ze1[j]*(z1fqs[j]-zcf[j]);
p1[1] =
xe2[j]*(x1f[j]-xcf[j])+ye2[j]*(y1f[j]-ycf[j])+ze2[j]*(z1fqs[j]-zcf[j]);
p1[2] =
nxf[j]*(x1f[j]-xcf[j])+nyf[j]*(y1f[j]-ycf[j])+nzf[j]*(z1fqs[j]-zcf[j]);

p2[0] =
xe1[j]*(x2f[j]-xcf[j])+ye1[j]*(y2f[j]-ycf[j])+ze1[j]*(z2fqs[j]-zcf[j]);
p2[1] =
xe2[j]*(x2f[j]-xcf[j])+ye2[j]*(y2f[j]-ycf[j])+ze2[j]*(z2fqs[j]-zcf[j]);
p2[2] =
nxf[j]*(x2f[j]-xcf[j])+nyf[j]*(y2f[j]-ycf[j])+nzf[j]*(z2fqs[j]-zcf[j]);

p3[0] =
xe1[j]*(x3f[j]-xcf[j])+ye1[j]*(y3f[j]-ycf[j])+ze1[j]*(z3fqs[j]-zcf[j]);
p3[1] =
xe2[j]*(x3f[j]-xcf[j])+ye2[j]*(y3f[j]-ycf[j])+ze2[j]*(z3fqs[j]-zcf[j]);
p3[2] =
nxf[j]*(x3f[j]-xcf[j])+nyf[j]*(y3f[j]-ycf[j])+nzf[j]*(z3fqs[j]-zcf[j]);

p4[0] =
xe1[j]*(x4f[j]-xcf[j])+ye1[j]*(y4f[j]-ycf[j])+ze1[j]*(z4fqs[j]-zcf[j]);
p4[1] =
xe2[j]*(x4f[j]-xcf[j])+ye2[j]*(y4f[j]-ycf[j])+ze2[j]*(z4fqs[j]-zcf[j]);
p4[2] =
nxf[j]*(x4f[j]-xcf[j])+nyf[j]*(y4f[j]-ycf[j])+nzf[j]*(z4fqs[j]-zcf[j]);

source(pcolloc[0],pcolloc[1],pcolloc[2],p1[0],p1[1],p1[2],
p2[0],p2[1],p2[2],p3[0],p3[1],p3[2],
p4[0],p4[1],p4[2],&srcphi, &dblphi);

*(S+count)= srcphi;
*(A+count)= dblphi;
count++;
}

for (k=0;k<totpanelswake;k++)
{

pcolloc[0] =
xe1wake[k]*(xp-xcwake[k])+ye1wake[k]*(yp-ycwake[k])+ze1wake[k]*(zp-zcwake[k]
);
pcolloc[1] =
xe2wake[k]*(xp-xcwake[k])+ye2wake[k]*(yp-ycwake[k])+ze2wake[k]*(zp-zcwake[k]
);
pcolloc[2] =
xe3wake[k]*(xp-xcwake[k])+ye3wake[k]*(yp-ycwake[k])+ze3wake[k]*(zp-zcwake[k]
);

p1[0] =
xe1wake[k]*(x1wake[k]-xcwake[k])+ye1wake[k]*(y1wake[k]-ycwake[k])+ze1wake[k]
*(z1wakeqs[k]-zcwake[k]);
p1[1] =
xe2wake[k]*(x1wake[k]-xcwake[k])+ye2wake[k]*(y1wake[k]-ycwake[k])+ze2wake[k]
*(z1wakeqs[k]-zcwake[k]);
p1[2] =
xe3wake[k]*(x1wake[k]-xcwake[k])+ye3wake[k]*(y1wake[k]-ycwake[k])+ze3wake[k]
*(z1wakeqs[k]-zcwake[k]);

p2[0] =
xe1wake[k]*(x2wake[k]-xcwake[k])+ye1wake[k]*(y2wake[k]-ycwake[k])+ze1wake[k]
*(z2wakeqs[k]-zcwake[k]);
p2[1] =
xe2wake[k]*(x2wake[k]-xcwake[k])+ye2wake[k]*(y2wake[k]-ycwake[k])+ze2wake[k]
*(z2wakeqs[k]-zcwake[k]);
p2[2] =
xe3wake[k]*(x2wake[k]-xcwake[k])+ye3wake[k]*(y2wake[k]-ycwake[k])+ze3wake[k]
*(z2wakeqs[k]-zcwake[k]);

p3[0] =
xe1wake[k]*(x3wake[k]-xcwake[k])+ye1wake[k]*(y3wake[k]-ycwake[k])+ze1wake[k]
*(z3wakeqs[k]-zcwake[k]);
p3[1] =
xe2wake[k]*(x3wake[k]-xcwake[k])+ye2wake[k]*(y3wake[k]-ycwake[k])+ze2wake[k]
*(z3wakeqs[k]-zcwake[k]);
p3[2] =
xe3wake[k]*(x3wake[k]-xcwake[k])+ye3wake[k]*(y3wake[k]-ycwake[k])+ze3wake[k]
*(z3wakeqs[k]-zcwake[k]);

p4[0] =
xe1wake[k]*(x4wake[k]-xcwake[k])+ye1wake[k]*(y4wake[k]-ycwake[k])+ze1wake[k]
*(z4wakeqs[k]-zcwake[k]);
p4[1] =
xe2wake[k]*(x4wake[k]-xcwake[k])+ye2wake[k]*(y4wake[k]-ycwake[k])+ze2wake[k]
*(z4wakeqs[k]-zcwake[k]);
p4[2] =
xe3wake[k]*(x4wake[k]-xcwake[k])+ye3wake[k]*(y4wake[k]-ycwake[k])+ze3wake[k]
*(z4wakeqs[k]-zcwake[k]);

source(pcolloc[0],pcolloc[1],pcolloc[2],p1[0],p1[1],p1[2],
p2[0],p2[1],p2[2],p3[0],p3[1],p3[2],
p4[0],p4[1],p4[2],&srcphi, &dblphi);

*(E+count2)= dblphi;
count2++;
}

}
return;
}

void mexFunction (int nlhs, mxArray *plhs[],
int nrhs, const mxArray *prhs[])
{

/* Input variables */

int totpanelsf, totpanelswake;
double eps;

double *xcf, *ycf, *zcf;
double *x1f, *y1f, *z1f;
double *x2f, *y2f, *z2f;
double *x3f, *y3f, *z3f;
double *x4f, *y4f, *z4f;
double *xe1, *ye1, *ze1;
double *xe2, *ye2, *ze2;
double *nxf, *nyf, *nzf;
double *z1fqs, *z2fqs, *z3fqs, *z4fqs;

double *xcwake, *ycwake, *zcwake;
double *x1wake, *y1wake, *z1wake;
double *x2wake, *y2wake, *z2wake;
double *x3wake, *y3wake, *z3wake;
double *x4wake, *y4wake, *z4wake;
double *xe1wake, *ye1wake, *ze1wake;
double *xe2wake, *ye2wake, *ze2wake;
double *xe3wake, *ye3wake, *ze3wake;
double *z1wakeqs, *z2wakeqs, *z3wakeqs, *z4wakeqs;

/* Output variables */

double *A, *S, *E;
/* Assign scalars to input */

totpanelsf = mxGetScalar(prhs[0]);
totpanelswake = mxGetScalar(prhs[1]);
eps = mxGetScalar(prhs[2]);

/* Assign pointers to input */

xcf = mxGetPr(prhs[3]);
.....
.....
z3wakeqs = mxGetPr(prhs[57]);
z4wakeqs = mxGetPr(prhs[58]);

/* Create Matrices for the outputs */

plhs[0] = mxCreateDoubleMatrix(totpanelsf,totpanelsf,mxREAL) ;
plhs[1] = mxCreateDoubleMatrix(totpanelsf,totpanelsf,mxREAL) ;
plhs[2] = mxCreateDoubleMatrix(totpanelsf,totpanelswake,mxRE AL);
/* Assign pointers to output */

A = mxGetPr(plhs[0]);
S = mxGetPr(plhs[1]);
E = mxGetPr(plhs[2]);

/* Call the coefficient matrix C subroutine */

coefficientmatrix(totpanelsf,totpanelswake,eps,
xcf, ycf, zcf,
x1f, y1f, z1f,
x2f, y2f, z2f,
x3f, y3f, z3f,
x4f, y4f, z4f,
xe1, ye1, ze1,
xe2, ye2, ze2,
nxf, nyf, nzf,
z1fqs, z2fqs, z3fqs, z4fqs,
xcwake, ycwake, zcwake,
x1wake, y1wake, z1wake,
x2wake, y2wake, z2wake,
x3wake, y3wake, z3wake,
x4wake, y4wake, z4wake,
xe1wake, ye1wake, ze1wake,
xe2wake, ye2wake, ze2wake,
xe3wake, ye3wake, ze3wake,
z1wakeqs, z2wakeqs, z3wakeqs, z4wakeqs,
A, S, E);
return;
}

"Peter Pichler" <pi*****@pobox.sk> wrote in message
news:40********@mk-nntp-2.news.uk.tiscali.com...
"Martijn van den Branden" <m.*************@student.tudelft.nl> wrote in
message news:bv**********@news.tudelft.nl...
Hi, <snip>
would someone care to take a glance at the code
and maybe identify some beginners mistake that causes the erroneous

results?
I can send the code
as an attachment.


Don't send in an attachment, trim it down to a reasonable size (no more

than a few KB, but take care not to cut out the bits that show the problem) and
post it here.

Peter

Nov 14 '05 #3

P: n/a
Peter Pichler wrote:
"Martijn van den Branden" <m.*************@student.tudelft.nl> wrote

<snip>
would someone care to take a glance at the code and maybe
identify some beginners mistake that causes the erroneous
results? I can send the code as an attachment.


Don't send in an attachment, trim it down to a reasonable size
(no more than a few KB, but take care not to cut out the bits
that show the problem) and post it here.


But make sure it is still a compilable complete program. Cut and
paste it, with neither tabs nor // comments, and keep line lengths
below 72.

--
Chuck F (cb********@yahoo.com) (cb********@worldnet.att.net)
Available for consulting/temporary embedded and systems.
<http://cbfalconer.home.att.net> USE worldnet address!

Nov 14 '05 #4

P: n/a
Martijn van den Branden wrote:
I've included the full code below, but at places i've deleted declarations
of variables
where they are obvious replaced by ...


This is hopeless. Don't post uncompilable code. Deleting the declarations
is close to antisocial. #including a non-standard header is silly; if we
can't see what's there, it doesn't exist.
--
Martin Ambuhl
Nov 14 '05 #5

P: n/a
I'm sorry, but i must say your reaction is close to antisocial. like i said
in my first message, i've close to no experience writing in c and i would
be very grateful if someone could point out some erroneous c syntax
from looking at the code, if there should be any, i didn't mean to offend
anyone.
I cut out some code because the first person to respond to my question
advised it.
AndI thought that if i'm lucky people that have experience writing mex files
might read my question and point me in some direction. I'm sure to them
mex.h is familiar, if still non-standard.

"Martin Ambuhl" <ma*****@earthlink.net> wrote in message
news:TA*****************@newsread3.news.atl.earthl ink.net...
Martijn van den Branden wrote:
I've included the full code below, but at places i've deleted declarations of variables
where they are obvious replaced by ...
This is hopeless. Don't post uncompilable code. Deleting the

declarations is close to antisocial. #including a non-standard header is silly; if we
can't see what's there, it doesn't exist.
--
Martin Ambuhl

Nov 14 '05 #6

P: n/a
ok, here it comes again :). thanks for your answer!

__________________________________________________ _______
#include "mex.h"
#include <math.h>
#define PI 3.14159

void source (double x, double y, double z, double x1, double y1, double z1,
double x2, double y2, double z2, double x3, double y3, double
z3,
double x4, double y4, double z4, double *srcphi, double
*dblphi)
{

double eps = 1e-10;
double d12,d23,d34,d41;
double r1,r2,r3,r4;
double e1,e2,e3,e4;
double h1,h2,h3,h4;
double m12,m23,m34,m41;

x1=x1+1*eps;
x2=x2-1*eps;
x3=x3+2*eps;
x4=x4-2*eps;

z1=0;
z2=0;
z3=0;
z4=0;

d12 = sqrt(pow((x2-x1),2) + pow((y2-y1),2));
d23 = sqrt(pow((x3-x2),2) + pow((y3-y2),2));
d34 = sqrt(pow((x4-x3),2) + pow((y4-y3),2));
d41 = sqrt(pow((x1-x4),2) + pow((y1-y4),2));

r1 = sqrt(pow((x-x1),2) + pow((y-y1),2) + pow(z,2));
r2 = sqrt(pow((x-x2),2) + pow((y-y2),2) + pow(z,2));
r3 = sqrt(pow((x-x3),2) + pow((y-y3),2) + pow(z,2));
r4 = sqrt(pow((x-x4),2) + pow((y-y4),2) + pow(z,2));

e1 = pow((x-x1),2) + pow(z,2);
e2 = pow((x-x2),2) + pow(z,2);
e3 = pow((x-x3),2) + pow(z,2);
e4 = pow((x-x4),2) + pow(z,2);

h1 = (x-x1)*(y-y1);
h2 = (x-x2)*(y-y2);
h3 = (x-x3)*(y-y3);
h4 = (x-x4)*(y-y4);

m12 = (y2-y1)/(x2-x1);
m23 = (y3-y2)/(x3-x2);
m34 = (y4-y3)/(x4-x3);
m41 = (y1-y4)/(x1-x4);

*(srcphi) = -1.0/(4*PI)*(
(
(((x-x1)*(y2-y1)-(y-y1)*(x2-x1))/d12)*log((r1+r2+d12)/(r1+r2-d12)) +
(((x-x2)*(y3-y2)-(y-y2)*(x3-x2))/d23)*log((r2+r3+d23)/(r2+r3-d23)) +
(((x-x3)*(y4-y3)-(y-y3)*(x4-x3))/d34)*log((r3+r4+d34)/(r3+r4-d34)) +
(((x-x4)*(y1-y4)-(y-y4)*(x1-x4))/d41)*log((r4+r1+d41)/(r4+r1-d41))
)
+fabs(z)*(
atan((m12*e1-h1)/(z*r1)) - atan((m12*e2-h2)/(z*r2)) +
atan((m23*e2-h2)/(z*r2)) - atan((m23*e3-h3)/(z*r3)) +
atan((m34*e3-h3)/(z*r3)) - atan((m34*e4-h4)/(z*r4)) +
atan((m41*e4-h4)/(z*r4)) - atan((m41*e1-h1)/(z*r1))
)
);

*(dblphi) = -1.0/(4*PI)*(
atan((m12*e1-h1)/(z*r1)) - atan((m12*e2-h2)/(z*r2))
+ atan((m23*e2-h2)/(z*r2)) - atan((m23*e3-h3)/(z*r3))
+ atan((m34*e3-h3)/(z*r3)) - atan((m34*e4-h4)/(z*r4))
+ atan((m41*e4-h4)/(z*r4)) - atan((m41*e1-h1)/(z*r1)));

return;
}


void coefficientmatrix(int totpanelsf, int totpanelswake, double eps,
double *xcf, double *ycf, double *zcf,
double *x1f, double *y1f, double *z1f,
double *x2f, double *y2f, double *z2f,
double *x3f, double *y3f, double *z3f,
double *x4f, double *y4f, double *z4f,
double *xe1, double *ye1, double *ze1,
double *xe2, double *ye2, double *ze2,
double *nxf, double *nyf, double *nzf,
double *z1fqs, double *z2fqs, double *z3fqs, double
*z4fqs,
double *xcwake, double *ycwake, double *zcwake,
double *x1wake, double *y1wake, double *z1wake,
double *x2wake, double *y2wake, double *z2wake,
double *x3wake, double *y3wake, double *z3wake,
double *x4wake, double *y4wake, double *z4wake,
double *xe1wake, double *ye1wake, double *ze1wake,
double *xe2wake, double *ye2wake, double *ze2wake,
double *xe3wake, double *ye3wake, double *ze3wake,
double *z1wakeqs, double *z2wakeqs, double *z3wakeqs,
double *z4wakeqs,
double *A, double *S, double *E)
{
int i,j,k,count = 0,count2=0;
double xp, yp, zp;
double pcolloc[3], p1[3], p2[3], p3[3], p4[3];
double srcphi, dblphi;

for(i=0;i<totpanelsf;i++)
{

xp = xcf[i]-nxf[i]*eps;
yp = ycf[i]-nyf[i]*eps;
zp = zcf[i]-nzf[i]*eps;

for (j=0;j<totpanelsf;j++)
{

pcolloc[0] = xe1[j]*(xp-xcf[j])+ye1[j]*(yp-ycf[j])+ze1[j]*(zp-zcf[j]);
pcolloc[1] = xe2[j]*(xp-xcf[j])+ye2[j]*(yp-ycf[j])+ze2[j]*(zp-zcf[j]);
pcolloc[2] = nxf[j]*(xp-xcf[j])+nyf[j]*(yp-ycf[j])+nzf[j]*(zp-zcf[j]);

p1[0] =
xe1[j]*(x1f[j]-xcf[j])+ye1[j]*(y1f[j]-ycf[j])+ze1[j]*(z1fqs[j]-zcf[j]);
p1[1] =
xe2[j]*(x1f[j]-xcf[j])+ye2[j]*(y1f[j]-ycf[j])+ze2[j]*(z1fqs[j]-zcf[j]);
p1[2] =
nxf[j]*(x1f[j]-xcf[j])+nyf[j]*(y1f[j]-ycf[j])+nzf[j]*(z1fqs[j]-zcf[j]);

p2[0] =
xe1[j]*(x2f[j]-xcf[j])+ye1[j]*(y2f[j]-ycf[j])+ze1[j]*(z2fqs[j]-zcf[j]);
p2[1] =
xe2[j]*(x2f[j]-xcf[j])+ye2[j]*(y2f[j]-ycf[j])+ze2[j]*(z2fqs[j]-zcf[j]);
p2[2] =
nxf[j]*(x2f[j]-xcf[j])+nyf[j]*(y2f[j]-ycf[j])+nzf[j]*(z2fqs[j]-zcf[j]);

p3[0] =
xe1[j]*(x3f[j]-xcf[j])+ye1[j]*(y3f[j]-ycf[j])+ze1[j]*(z3fqs[j]-zcf[j]);
p3[1] =
xe2[j]*(x3f[j]-xcf[j])+ye2[j]*(y3f[j]-ycf[j])+ze2[j]*(z3fqs[j]-zcf[j]);
p3[2] =
nxf[j]*(x3f[j]-xcf[j])+nyf[j]*(y3f[j]-ycf[j])+nzf[j]*(z3fqs[j]-zcf[j]);

p4[0] =
xe1[j]*(x4f[j]-xcf[j])+ye1[j]*(y4f[j]-ycf[j])+ze1[j]*(z4fqs[j]-zcf[j]);
p4[1] =
xe2[j]*(x4f[j]-xcf[j])+ye2[j]*(y4f[j]-ycf[j])+ze2[j]*(z4fqs[j]-zcf[j]);
p4[2] =
nxf[j]*(x4f[j]-xcf[j])+nyf[j]*(y4f[j]-ycf[j])+nzf[j]*(z4fqs[j]-zcf[j]);

source(pcolloc[0],pcolloc[1],pcolloc[2],p1[0],p1[1],p1[2],
p2[0],p2[1],p2[2],p3[0],p3[1],p3[2],
p4[0],p4[1],p4[2],&srcphi, &dblphi);

*(S+count)= srcphi;
*(A+count)= dblphi;
count++;
}

for (k=0;k<totpanelswake;k++)
{

pcolloc[0] =
xe1wake[k]*(xp-xcwake[k])+ye1wake[k]*(yp-ycwake[k])+ze1wake[k]*(zp-zcwake[k]
);
pcolloc[1] =
xe2wake[k]*(xp-xcwake[k])+ye2wake[k]*(yp-ycwake[k])+ze2wake[k]*(zp-zcwake[k]
);
pcolloc[2] =
xe3wake[k]*(xp-xcwake[k])+ye3wake[k]*(yp-ycwake[k])+ze3wake[k]*(zp-zcwake[k]
);

p1[0] =
xe1wake[k]*(x1wake[k]-xcwake[k])+ye1wake[k]*(y1wake[k]-ycwake[k])+ze1wake[k]
*(z1wakeqs[k]-zcwake[k]);
p1[1] =
xe2wake[k]*(x1wake[k]-xcwake[k])+ye2wake[k]*(y1wake[k]-ycwake[k])+ze2wake[k]
*(z1wakeqs[k]-zcwake[k]);
p1[2] =
xe3wake[k]*(x1wake[k]-xcwake[k])+ye3wake[k]*(y1wake[k]-ycwake[k])+ze3wake[k]
*(z1wakeqs[k]-zcwake[k]);

p2[0] =
xe1wake[k]*(x2wake[k]-xcwake[k])+ye1wake[k]*(y2wake[k]-ycwake[k])+ze1wake[k]
*(z2wakeqs[k]-zcwake[k]);
p2[1] =
xe2wake[k]*(x2wake[k]-xcwake[k])+ye2wake[k]*(y2wake[k]-ycwake[k])+ze2wake[k]
*(z2wakeqs[k]-zcwake[k]);
p2[2] =
xe3wake[k]*(x2wake[k]-xcwake[k])+ye3wake[k]*(y2wake[k]-ycwake[k])+ze3wake[k]
*(z2wakeqs[k]-zcwake[k]);

p3[0] =
xe1wake[k]*(x3wake[k]-xcwake[k])+ye1wake[k]*(y3wake[k]-ycwake[k])+ze1wake[k]
*(z3wakeqs[k]-zcwake[k]);
p3[1] =
xe2wake[k]*(x3wake[k]-xcwake[k])+ye2wake[k]*(y3wake[k]-ycwake[k])+ze2wake[k]
*(z3wakeqs[k]-zcwake[k]);
p3[2] =
xe3wake[k]*(x3wake[k]-xcwake[k])+ye3wake[k]*(y3wake[k]-ycwake[k])+ze3wake[k]
*(z3wakeqs[k]-zcwake[k]);

p4[0] =
xe1wake[k]*(x4wake[k]-xcwake[k])+ye1wake[k]*(y4wake[k]-ycwake[k])+ze1wake[k]
*(z4wakeqs[k]-zcwake[k]);
p4[1] =
xe2wake[k]*(x4wake[k]-xcwake[k])+ye2wake[k]*(y4wake[k]-ycwake[k])+ze2wake[k]
*(z4wakeqs[k]-zcwake[k]);
p4[2] =
xe3wake[k]*(x4wake[k]-xcwake[k])+ye3wake[k]*(y4wake[k]-ycwake[k])+ze3wake[k]
*(z4wakeqs[k]-zcwake[k]);

source(pcolloc[0],pcolloc[1],pcolloc[2],p1[0],p1[1],p1[2],
p2[0],p2[1],p2[2],p3[0],p3[1],p3[2],
p4[0],p4[1],p4[2],&srcphi, &dblphi);

*(E+count2)= dblphi;
count2++;
}

}
return;
}

void mexFunction (int nlhs, mxArray *plhs[],
int nrhs, const mxArray *prhs[])
{

/* Input variables */

int totpanelsf, totpanelswake;
double eps;

double *xcf, *ycf, *zcf;
double *x1f, *y1f, *z1f;
double *x2f, *y2f, *z2f;
double *x3f, *y3f, *z3f;
double *x4f, *y4f, *z4f;
double *xe1, *ye1, *ze1;
double *xe2, *ye2, *ze2;
double *nxf, *nyf, *nzf;
double *z1fqs, *z2fqs, *z3fqs, *z4fqs;

double *xcwake, *ycwake, *zcwake;
double *x1wake, *y1wake, *z1wake;
double *x2wake, *y2wake, *z2wake;
double *x3wake, *y3wake, *z3wake;
double *x4wake, *y4wake, *z4wake;
double *xe1wake, *ye1wake, *ze1wake;
double *xe2wake, *ye2wake, *ze2wake;
double *xe3wake, *ye3wake, *ze3wake;
double *z1wakeqs, *z2wakeqs, *z3wakeqs, *z4wakeqs;

/* Output variables */

double *A, *S, *E;
/* Assign scalars to input */

totpanelsf = mxGetScalar(prhs[0]);
totpanelswake = mxGetScalar(prhs[1]);
eps = mxGetScalar(prhs[2]);

/* Assign pointers to input */

xcf = mxGetPr(prhs[3]);
ycf = mxGetPr(prhs[4]);
zcf = mxGetPr(prhs[5]);

x1f = mxGetPr(prhs[6]);
y1f = mxGetPr(prhs[7]);
z1f = mxGetPr(prhs[8]);

x2f = mxGetPr(prhs[9]);
y2f = mxGetPr(prhs[10]);
z2f = mxGetPr(prhs[11]);

x3f = mxGetPr(prhs[12]);
y3f = mxGetPr(prhs[13]);
z3f = mxGetPr(prhs[14]);

x4f = mxGetPr(prhs[15]);
y4f = mxGetPr(prhs[16]);
z4f = mxGetPr(prhs[17]);

xe1 = mxGetPr(prhs[18]);
ye1 = mxGetPr(prhs[19]);
ze1 = mxGetPr(prhs[20]);

xe2 = mxGetPr(prhs[21]);
ye2 = mxGetPr(prhs[22]);
ze2 = mxGetPr(prhs[23]);

nxf = mxGetPr(prhs[24]);
nyf = mxGetPr(prhs[25]);
nzf = mxGetPr(prhs[26]);

z1fqs = mxGetPr(prhs[27]);
z2fqs = mxGetPr(prhs[28]);
z3fqs = mxGetPr(prhs[29]);
z4fqs = mxGetPr(prhs[30]);

xcwake = mxGetPr(prhs[31]);
ycwake = mxGetPr(prhs[32]);
zcwake = mxGetPr(prhs[33]);

x1wake = mxGetPr(prhs[34]);
y1wake = mxGetPr(prhs[35]);
z1wake = mxGetPr(prhs[36]);

x2wake = mxGetPr(prhs[37]);
y2wake = mxGetPr(prhs[38]);
z2wake = mxGetPr(prhs[39]);

x3wake = mxGetPr(prhs[40]);
y3wake = mxGetPr(prhs[41]);
z3wake = mxGetPr(prhs[42]);

x4wake = mxGetPr(prhs[43]);
y4wake = mxGetPr(prhs[44]);
z4wake = mxGetPr(prhs[45]);

xe1wake = mxGetPr(prhs[46]);
ye1wake = mxGetPr(prhs[47]);
ze1wake = mxGetPr(prhs[48]);

xe2wake = mxGetPr(prhs[49]);
ye2wake = mxGetPr(prhs[50]);
ze2wake = mxGetPr(prhs[51]);

xe3wake = mxGetPr(prhs[52]);
ye3wake = mxGetPr(prhs[53]);
ze3wake = mxGetPr(prhs[54]);

z1wakeqs = mxGetPr(prhs[55]);
z2wakeqs = mxGetPr(prhs[56]);
z3wakeqs = mxGetPr(prhs[57]);
z4wakeqs = mxGetPr(prhs[58]);

/* Create Matrices for the outputs */

plhs[0] = mxCreateDoubleMatrix(totpanelsf,totpanelsf,mxREAL) ;
plhs[1] = mxCreateDoubleMatrix(totpanelsf,totpanelsf,mxREAL) ;
plhs[2] = mxCreateDoubleMatrix(totpanelsf,totpanelswake,mxRE AL);
/* Assign pointers to output */

A = mxGetPr(plhs[0]);
S = mxGetPr(plhs[1]);
E = mxGetPr(plhs[2]);

/* Call the coefficient matrix C subroutine */

coefficientmatrix(totpanelsf,totpanelswake,eps,
xcf, ycf, zcf,
x1f, y1f, z1f,
x2f, y2f, z2f,
x3f, y3f, z3f,
x4f, y4f, z4f,
xe1, ye1, ze1,
xe2, ye2, ze2,
nxf, nyf, nzf,
z1fqs, z2fqs, z3fqs, z4fqs,
xcwake, ycwake, zcwake,
x1wake, y1wake, z1wake,
x2wake, y2wake, z2wake,
x3wake, y3wake, z3wake,
x4wake, y4wake, z4wake,
xe1wake, ye1wake, ze1wake,
xe2wake, ye2wake, ze2wake,
xe3wake, ye3wake, ze3wake,
z1wakeqs, z2wakeqs, z3wakeqs, z4wakeqs,
A, S, E);
return;
}

"CBFalconer" <cb********@yahoo.com> wrote in message
news:40***************@yahoo.com...
Peter Pichler wrote:
"Martijn van den Branden" <m.*************@student.tudelft.nl> wrote

<snip>
would someone care to take a glance at the code and maybe
identify some beginners mistake that causes the erroneous
results? I can send the code as an attachment.


Don't send in an attachment, trim it down to a reasonable size
(no more than a few KB, but take care not to cut out the bits
that show the problem) and post it here.


But make sure it is still a compilable complete program. Cut and
paste it, with neither tabs nor // comments, and keep line lengths
below 72.

--
Chuck F (cb********@yahoo.com) (cb********@worldnet.att.net)
Available for consulting/temporary embedded and systems.
<http://cbfalconer.home.att.net> USE worldnet address!

Nov 14 '05 #7

P: n/a
Martijn van den Branden wrote:

But make sure it is still a compilable complete program. Cut and
paste it, with neither tabs nor // comments, and keep line lengths
below 72.


ok, here it comes again :). thanks for your answer!

.... great big snip ...

Note the words compilable complete above. Non-standard include
files must be present, together with their associated source.
Your exercise in cutting it down to that in the first place will
often reveal the problem.

Without these rules the result is usually pure gibberish.

Oh yes - please do not toppost. I fixed this one.

--
Chuck F (cb********@yahoo.com) (cb********@worldnet.att.net)
Available for consulting/temporary embedded and systems.
<http://cbfalconer.home.att.net> USE worldnet address!
Nov 14 '05 #8

P: n/a
Martijn van den Branden wrote:
I've included the full code below, but at places i've deleted declarations
of variables
where they are obvious replaced by ...

Thanks in advance,

Martijn


#include "mex.h"


gcc -g -W -Wall -ansi -pedantic -o foo foo.c -lm
foo.c:1: mex.h: No such file or directory

That's going to be a problem for anyone trying to help you.

<snip>

--
Richard Heathfield : bi****@eton.powernet.co.uk
"Usenet is a strange place." - Dennis M Ritchie, 29 July 1999.
C FAQ: http://www.eskimo.com/~scs/C-faq/top.html
K&R answers, C books, etc: http://users.powernet.co.uk/eton
Nov 14 '05 #9

P: n/a
Sorry guys. I understand it's no use without mex.h, except for those maybe
who use matlab and write mex (matlab executables) themselves, and have
it installed with their matlab product. I'm sure the people at mathworks
would
not like it if i distributed mex.h myself :).

Thanks for your time!


"CBFalconer" <cb********@yahoo.com> wrote in message
news:40***************@yahoo.com...
Martijn van den Branden wrote:

But make sure it is still a compilable complete program. Cut and
paste it, with neither tabs nor // comments, and keep line lengths
below 72.


ok, here it comes again :). thanks for your answer!

... great big snip ...

Note the words compilable complete above. Non-standard include
files must be present, together with their associated source.
Your exercise in cutting it down to that in the first place will
often reveal the problem.

Without these rules the result is usually pure gibberish.

Oh yes - please do not toppost. I fixed this one.

--
Chuck F (cb********@yahoo.com) (cb********@worldnet.att.net)
Available for consulting/temporary embedded and systems.
<http://cbfalconer.home.att.net> USE worldnet address!

Nov 14 '05 #10

P: n/a
"Martijn van den Branden" <m.*************@student.tudelft.nl> wrote in
message news:bv**********@news.tudelft.nl...
Sorry guys. I understand it's no use without mex.h, except for those maybe
who use matlab and write mex (matlab executables) themselves, and have
it installed with their matlab product. I'm sure the people at mathworks
would
not like it if i distributed mex.h myself :).
I can see that you still ignore at least three independent requests not to
top post. Top posting is a sign of cluelesness at best, ignoring other
people's polite requests is downright rude.
Thanks for your time!


For some reason, I have not yet seen my post from last night. In case it
does not make it into the wild, it was (other than mentioning quite a few
style issues) about the log() function. In C, log() is your high school
equivalent of ln. If you want decimal logarithms, use log10(). Dunno if this
is the source of your problem, your description was a bit vague.

Peter
Nov 14 '05 #11

P: n/a
"Peter Pichler" <pi*****@pobox.sk> wrote in message
news:40**********@mk-nntp-2.news.uk.tiscali.com...
"Martijn van den Branden" <m.*************@student.tudelft.nl> wrote in
message news:bv**********@news.tudelft.nl...
Sorry guys. I understand it's no use without mex.h, except for those maybe who use matlab and write mex (matlab executables) themselves, and have
it installed with their matlab product. I'm sure the people at mathworks
would
not like it if i distributed mex.h myself :).
I can see that you still ignore at least three independent requests not to
top post. Top posting is a sign of cluelesness at best, ignoring other
people's polite requests is downright rude.
Thanks for your time!


For some reason, I have not yet seen my post from last night. In case it
does not make it into the wild, it was (other than mentioning quite a few
style issues) about the log() function. In C, log() is your high school
equivalent of ln. If you want decimal logarithms, use log10(). Dunno if

this is the source of your problem, your description was a bit vague.

Peter


I intended to use log. Sorry, i didn't mean to be rude, i just never heard
of
'topposting' before, this is also my first post to a newsgroup, i thought it
had something to do with the code. I admit that is clueless. From now
on, i solemny swear, i will put into good practice all the advice you gave
me on posting ;)

Martijn
Nov 14 '05 #12

P: n/a
You might try asking in

comp.soft-sys.matlab

Mathworks set up a "portal" at

http://newsreader.mathworks.com/We**...oft-sys.matlab

Good luck,

Matt Wolinsky
Nov 14 '05 #13

P: n/a
On Sat, 31 Jan 2004 22:34:15 +0100, "Martijn van den Branden"
<m.*************@student.tudelft.nl> wrote:
I'm sorry, but i must say your reaction is close to antisocial. like i said
in my first message, i've close to no experience writing in c and i would
be very grateful if someone could point out some erroneous c syntax
from looking at the code, if there should be any, i didn't mean to offend
anyone.
If there are syntax errors in your code, your compiler should point
them out. Make sure you have its warning level set for maximum
sensitivity. If the compiler produces error messages which you don't
understand, post the messages and the offending lines.
I cut out some code because the first person to respond to my question
advised it.
AndI thought that if i'm lucky people that have experience writing mex files
might read my question and point me in some direction. I'm sure to them
mex.h is familiar, if still non-standard.

Then you should ask in some forum where "mex files" are on-topic.
Surely there would be a better chance of finding "people that have
experience writing mex files" in such a forum.

When I search Google groups for "matlab", eight of the first ten
results are from a newsgroup called "comp.soft-sys.matlab". I would
suggest that this is a better place to start. Now, couldn't you have
found that out yourself?

--
Al Balmer
Balmer Consulting
re************************@att.net
Nov 14 '05 #14

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