PROGRAM FOURPL

General fourier inversion program

Description:

A general program to calculate Fourier sums. It allows fourier sections, projections, general plane sections and error maps to be calculated.
Facilities are provided for saving and restoring maps to and from file. The output can be recorded by printer and/or plotted as a contoured map.
This same program masquerades under the name of FOURL\_TK when loaded with the
Textronix library, as FOURPL\_PG when loaded with the PGPLOT library and as
FOURPL\_PS when loaded with the postscript plotting routines.

Input:

The crystal data file must contain:

A C card with the cell dimensions
S cards giving the symmetry
M cards defining which maps to draw and how they are defined

(see the CCSL users' manual)

A file containing the data from which the Fourier sum is to be calculated. This is in general supposed to contain h, k, l, F1, F2, F3 ... in format (3I5,nF10.5). The number of F's to be read and ther interpretation depends on the values of FTYP and DTYP read from the M cards . The range of hkl must span the asymmetric unit of reciprocal space and not more.
If there is an M GET card : a file containing a previously "saved" map.
If there is an M READ card : a file containing a previously dumped map.

Output:

The usual listing file reporting the data which have been read. If there is an M PRIN card this file also contains the values of the fourier summation at the points requested. These numbers are rounded to integers so the scale (given by M SCAL) must be chosen to ensure they are not all zero.
If there is an M PLOT card : graphical output whose form depends upon the graphical library being used.
If there is an M SAVE card : An output file containing the "saved" maps.

Notes:

To obtain the different versions of the program it must be linked with the appropriate version of the hardware dependent subroutines PIGLET etc. from thethe PIG section of the library. Currently available are:

PIGPL .............. for Benson plotter (obsolete)
PIGPG .............. for PGPLOT library (T.J. Pearson)
PIGTEK ............. forTektronix library (obsolete)
PIGGKS ............. for GKS
PIGPOS ............. Postscript output

and, except in the case of PIGPOS, the appropriate graphics library

Running the program:

Ensure that the terminal from which the program is to be run is appropriate to the graphics library with which the program was linked.
On running the program the user is asked for the name of the crystal data file, and the name of the file containing data for the Fourier coefficients (reflection data). Any further dialogue is driven by the graphics library and is usually confined to an enquiry as to whether a hard copy of a map is required. If no contour values are given on M cards and an M PLOT card is present, the program will ask for them interactively.

Calls:

ATMPLT ERRMAP ERRMES FORIER FOUR1Z FOURGP FRAME GETMAP MAPCON MAPDRW MAPFRA MAPTIT NOPFIL OPSYM PICMOV PIGLET PLTTXT PREFIN PRNTMP RECIP SAVMAP SETFOU SPCSET STPLOT UNUSYM USYM

Common blocks used:

/IOUNIT/ to use LPT LUNI

/MAPDA/ to use OUTLIM NDIM NOBSIN NUSED MODET

/MREAD/ to use all members

/PLOMAP/ to use WIDPIC HGTPIC

*** FOURPL adjusted by PJB April/June 2006 C142/3 ***

Fourier Calculations . . . . . . . Main Program

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P. Jane Brown e-mail: brown@ill.fr
Institut Laue Langevin,
Grenoble, FRANCE