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diff --git a/src/README b/src/README new file mode 100644 index 0000000..9aaf01c --- /dev/null +++ b/src/README @@ -0,0 +1,79 @@ +$Header$ + +This directory contains the interpolator registered for + CCTK_InterpLocalUniform() +under the names + "Lagrange polynomial interpolation" # a synonym for the next one... + "Lagrange polynomial interpolation (tensor product)" + "Lagrange polynomial interpolation (maximum degree)" + "Hermite polynomial interpolation" + + +The source code files are as follows: +* startup.c registers the interpolation operators +* InterpLocalUniform.h is an overall header file for the whole interpolator +* InterpLocalUniform.c is the top-level driver: it gets the various + options from the parameter table, then decodes + (N_dims, molecule_family, order, smoothing) + and calls the appropriate subfunction to do the actual interpolation, + then finally stores some results back in the parameter table. +* [123]d.cube.order*.smooth*.c define the individual interpolation + subfunctions. Each of them just #defines a whole bunch of macros, + then #includes template.c (which has the actual code). +* template.h defines a prototype for the function defined by template.c +* template.c is the actual interpolation code. It is written in + terms of a large number of macros, which should be #defined + before #including template.c. There's a long block comment + "Implementation notes:" at the start of the function, which + gives an outline of how the function works. (This is probably + the best place to start reading if you want to understand this + interpolator!) All the actual interpolation is done by + Maple-generated code fragments in the [123]d.coeffs/directories; + template.c uses various macros to tell it which fragments to + #include. +* molecule_posn.c contains the AEILocalInterp_molecule_posn() function + to compute where in the grid each (an) interpolation molecule should + be centered for each (a given) interpolation point. +* util.c contains some low-level utility routines +* [123]d.maple are the top-level Maple code files; they call + various functions in interpolate.maple and util.maple to do + the actual work. +* interpolate.maple contains the high-level Maple code for + computing an interpolant and manipulating/printing it in various + ways +* util.maple contains low-level utility routines +* makefile is a makefile for... +* test_molecule_posn.c is a standalone test driver for the code + in molecule_posn.c . By default it runs a large set of (around 100) + test cases stored in a table in the code. + +The subdirectories are as follows: +* Lagrange-tensor-product/ contains the code for the Lagrange polynomial + interpolator using tensor-product bases for multiple dimensions. +* Lagrange-maximum-degree/ contains the code for the Lagrange polynomial + interpolator using maximum-degree bases for multiple dimensions. +* Hermite/ contains the code for the Hermite polynomial interpolator. +* common/ contains low-level code common to both the Lagrange and + the Hermite interpolators. + + +To add a new combination of (N_dims, molecule_family, order, smoothing), +to this interpolator, you need to +* edit the appropriate Maple script (1d.maple, 2d.maple, 3d.maple, etc) + to generate the coefficients and write the appropriate files +* edit the makefile to create the appropriate directory or directories, + and if necessary add any new targets +* 'make' as appropriate to create the new coefficients etc + [note this take a *lot* of CPU time; see the comments in the Makefiles + for just how long some sample cases take] +* edit InterpLocalUniform.c to add the new case to the decoding + switch statements +* create an appropriate "script" file which defines the right macros, + then does a + #include "template.c" + to define the actual interpolation function; the best way to create + the script file is just to copy an existing one + (eg. 2d.cube.order3.smooth0.c) +* add the appropriate entry to all_prototypes.h to define a prototype + for the actual interpolation function +* add the new "script" file to the list in make.code.defn |