Encyclopaedia Index

Contents

  1. About PINTO
  2. What PINTO does
  3. What PINTO cannot do
  4. The interaction between PINTO and other PHOENICS programs
  5. About Q1PIN
  6. How to use PINTO

1. About PINTO

PINTO, the PHOENICS INTerpolation prOgram, is a stand-alone code of the PHOENICS program that can be used to transfer the results calculated by EARTH on to finer or coarser grids.

PINTO proceeds by interpolation on to the new grid the values of the variables saved by EARTH in the PHI file for the old grid. These variables are those for which the user requested, in the Q1 file, a solution (through SOLVE) or the allocation of storage space (through STORE).

Thus, PINTO can be used to:

PINTO takes its input from a special Q1 file (Q1PIN), which accepts a subset of instructions of the PHOENICS Input Language (PIL) with some extensions.

As an aid to the user, PINTO records its transaction with the command-file Q1PIN in a log file (PINLOG), in which syntactical errors made in the command statements are recorded. The coordinates of the new grid are also written to this file, both for checking and for copying into the Q1 file that will be used for the fine-grid calculation.

2. What PINTO does

3. What PINTO cannot do

4. The interaction between PINTO and other PHOENICS programs

PINTO will normally be used in combination with other PHOENICS programs, as follows:

  1. The user will have a Q1 file that performs a coarse-grid computation. After running the SATELLITE and EARTH, a PHI file with the result for the coarse grid will be generated.

  2. The user will then write a Q1PIN file for the interpolation of the coarse-grid results into the fine grid. The Q1PIN file will have settings to define the new grid and to control the format and name of the output files.

  3. PINTO will then be run by entering the command runpin (or runpins for Salford version). On execution, PINTO will read in the Q1PIN file and will generate a PHI-like file with the new file values for the variables on the refined grid. APINLOG file will also be generated, containing a description of the new grid and any error message.

    After a PINTO run, it is essential to inspect the PINLOG file for errors. PINTO does not write any error messages to the screen, and the contents of this is therefore the same for successful and erroneous runs.

  4. The new PHI file can then be used by the user in several ways:

A flow chart of PINTO is provided below:



                                                                                 Q1

                                                                                |

                                     SATELLITE  

                                         |

                                       EARDAT

                                         |

                    PREFIX              EARTH

                      |                  |                                 

          PINCON      |     Q1PIN       PHI (or PHIDA)

            |                |          |                                     |       

     ---------------------------------------------

     |                PINTO                      |

     ---------------------------------------------

          |                                                                          

      NPHI (or NPHIDA)        PINLOG       

          |

     EARTH (or PHOTON)

5. About Q1PIN

Q1PIN, input file for PINTO, is similar in concept to the Q1 file used by the SATELLITE, which the reader is assumed to be familiar with.

Q1PIN is divided into 3 groups, as follows:

The set of commands used by PINTO comprises some PIL commands, and some additional ones which are unique to PINTO. As in the PIL, the group structure of PINTO has been conceived just as an aid-memory for the user: PINTO commands do not need to be in the group they belong to.

Unlike the Q1 file, the Q1PIN file does not need to have a special first line (TALK=T;RUN=1,1) of the Q1 file; but the end of the Q1PIN file must be flagged with a STOP command.

Finally, PINTO commands must start in the first or second column of the file; and all other lines are treated as comments.

PINTO language is much more limited than the PIL. Please refer to TR218 for what commands will be recognised by PINTO.

6. How to use PINTO

This section describes how to use PINTO to perform the file handling and the grid interpolation.

1. File handling.

The steps in the execution of the file handling are:

Similarly, a PHIDA file produced by EARTH, when PHIDA=T is set in prefix, can be converted to a formatted sequential file, NPHI by modifying the Q1PIN file and replacing LDA=T by LFS=T.

2. Grid interpolation.

The steps in the execution of the grid interpolation are: