1 | |
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2 | Hej Jakob |
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3 | |
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4 | (I assume you understand danish) |
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5 | |
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6 | > I saw your announcement of Pypar on comp.lang.python.announce. In our |
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7 | > programs, we are using Konrad Hinsen's Scientific Python module. I |
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8 | > have a small technical question. You write that one advantage of your |
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9 | > approach is, that one does not need a special version of the Python |
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10 | > executable, just the pypar module. In Scientific Python it is |
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11 | > necessary to modify Python because MPI requires that MPI_Init is |
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12 | > called before the program looks at its command line arguments, and |
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13 | > Python needs to look at its command line arguments to figure out which |
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14 | > script to run. |
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15 | |
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16 | Jeg har aldrig rigtigt forstaaet hvorfor det skulle vaere noedvendigt. |
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17 | Derfor gik jeg igang med at implementere et interface hvor |
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18 | Python oversetteren forbliver uaendret. |
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19 | MPI_init har selvfoelgelig ikke adgang til commandline parametre |
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20 | - saa det er prisen for min tilgang. |
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21 | |
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22 | > How do you bypass this problem? I know there are MPI |
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23 | > implementations where this is not a problem as MPI only adds extra |
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24 | > stuff to the command-line on the non-master nodes, but there are some |
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25 | > implementation (MPICH, for example) where the whole command line is |
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26 | > replaced with MPI stuff and the command line is only restored when |
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27 | > MPI_Init is called. |
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28 | |
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29 | Det er muligt at pypar vil have problemer med det. |
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30 | Jeg har imidlertid testet pypar under LAM/Mpi (linux), |
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31 | Native MPI for DEC Alpha og MPICH for Sun enterprise. |
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32 | Jeg kunne ikke umiddelbart faa ideen til at virke under MPICH/Linux - maaske |
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33 | pga det problem du beskriver. |
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34 | |
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35 | > I am very interested to hear if you have found an elegant way to solve |
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36 | > this, |
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37 | |
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38 | Jeg har ikke fundet en elegant loesning - maaske snarere en vej udenom: |
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39 | Problemet er rent teoretisk for de implementationer jeg bruger |
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40 | og kan ignoreres. |
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41 | |
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42 | |
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43 | > as it is slightly annoying to have to have an extra version of |
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44 | > the Python executable. |
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45 | |
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46 | Ja - det var det jeg taenkte. |
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47 | |
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48 | Hvis du har lyst kan du hjaelpe med at udvikle pypar ideen ? |
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49 | |
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50 | Mvh |
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51 | Ole |
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52 | |
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53 | ------------------------------------------------------------------- |
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54 | Ole Nielsen | Email: Ole.Nielsen@anu.edu.au |
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55 | ------------------------------------------------------------------- |
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56 | School of Mathematical Sciences| Phone: +61 2 6125 3873 (Direct) |
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57 | Australian National University | Fax: +61 2 6125 5549 |
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58 | Canberra ACT 0200 | |
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59 | Australia | |
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60 | ------------------------------------------------------------------- |
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61 | |
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