Re: NURBS package: 'nrbeval' crashes when calling 'bspeval'

[c.]

On 24 Apr 2013, at 16:56, afullo <address@hidden> wrote:

> After having successfully installed and loaded the NURBS package (see  here
> <http://octave.1599824.n4.nabble.com/At-least-apparently-unable-to-install-packages-tp4652176.html>
>  
> ), its fundamental command /nrbeval/ (points of a NURBS from parametric
> values) crashes when it calls /bspeval/: 
> 
> /error: nrbeval:
> /usr/lib/x86_64-linux-gnu/octave/packages/nurbs-1.3.6/x86_64-pc-linux-gnu-api-v48+/bspeval.oct:
> failed to load:
> /usr/lib/x86_64-linux-gnu/octave/packages/nurbs-1.3.6/x86_64-pc-linux-gnu-api-v48+/bspeval.oct:
> undefined symbol: GOMP_parallel_start
> error: called from:
> error:   /usr/share/octave/packages/nurbs-1.3.6/nrbeval.m at line 233,
> column 7/
> 
> This is row 233 of nrbeval.m:
> 
> /val = bspeval(nurbs.order-1,nurbs.coefs,nurbs.knots,tt);/
> 
> Why does it fail to work?
> 
> Thanks in advance.


ciao Fabio,

As far as I can tell this looks like an error in the configuration for gcc on 
ubuntu.
A simple workaround is to disble all OMP pragmas in .cc files.

In order to do this you have to:

1) download the nurbs package from svn:

svn checkout 
http://svn.code.sf.net/p/octave/code/trunk/octave-forge/trunk/octave-forge/extra/nurbs
 

2) search for the string "#pragma" in all .cc files and replace it by 
"//#pragma":

sed -i".bak" -e 's|#pragma|//#pragma|g' nurbs/inst/*

3) create a .tar.gz file from the package:

tar cvzf nurbs.tar.gz nurbs

4) install the modified package

octave -q
>> pkg install nurbs.tar.gz


let me know if this works.
c.