problem about running gerris
 

Dear all:
I have successfully installed the Gerris on my ubuntu 10.10 system.
When i run program, it was usually terminated by
\"/tmp/gfs3tesOV: 1: convert: not found\". Then, i think to created a folder
\"/tmp/gfs3tesOV\" and run again. Usually, after some times, we can
fix the situation. i wonder if there is a smarter solution.

EX:
A@A-Workstation:~/Gerrisex$ gerris2D cylinder.gfs

...
Approximate projection
niter: 1
residual.bias: 6.473e-06 -4.639e-07
residual.first: 4.749e-05 3.828e-06 12
residual.second: 1.210e-04 6.062e-06 20
residual.infty: 2.109e-03 6.354e-05 33
step: 1650 t: 15.00000000 dt: 9.112460e-03 cpu: 372.89000000 real: 377.32398700
Balance summary: 1 PE
domain min: 20982 avg: 20982 | 0 max: 20982
MAC projection before after rate
niter: 2
residual.bias: 5.365e-07 2.401e-06
residual.first: 3.146e-05 3.431e-06 3
residual.second: 1.109e-04 1.267e-05 3
residual.infty: 3.209e-03 1.882e-04 4.1
Approximate projection
niter: 1
residual.bias: 6.561e-07 -1.977e-06
residual.first: 5.412e-05 4.882e-06 11
residual.second: 1.437e-04 1.098e-05 13
residual.infty: 2.704e-03 1.214e-04 22
...
/tmp/gfsid5e1f: 1: convert: not found

so how can i do ?
thanks