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Diffstat (limited to 'funtools/fitsy/cardfind.c')
| -rw-r--r-- | funtools/fitsy/cardfind.c | 201 |
1 files changed, 201 insertions, 0 deletions
diff --git a/funtools/fitsy/cardfind.c b/funtools/fitsy/cardfind.c new file mode 100644 index 0000000..999d143 --- /dev/null +++ b/funtools/fitsy/cardfind.c @@ -0,0 +1,201 @@ +/* Fitsy FITS card find routines. + + DESCRIPTION + + Routines to find FITS cards in a FITS headers data structure. + + EXAMPLES ++ + + /-* Declair some fitsy types. + *-/ + #FITSHead fits; + #FITSCard foo; + #FITSCard goo; + #FITSBuff key; + + /-* Look up a card using sequential search. + *-/ + #ft_cardkey(key, "FOO"); + foo = #ft_cardfind(fits, key, 0); + + /-* This is the same thing. But the card is added to the header + if it isn't found. This will also invalidate the index if + there is one. + *-/ + #ft_cardkey(key, "FOO"); + foo = #ft_cardfind(fits, key, 1); + + /-* Now index the header so that searches are faster. #ft_cardfind + will automatically use the index if its valid. + *-/ + #ft_index(fits); + #ft_cardkey(key, "GOO", 0); + goo = #ft_cardfind(fits, key, 0); ++ + */ + +#include "fitsy.h" + +int ft_compare(a, b) + char **a; + char **b; + +{ + int ax, bx; + + if ( !strncmp(*a, *b, 5) + && ((*a)[5] != ' ') && ((*b)[5] != ' ') + && (ax = atoi(&(*a)[5])) + && (bx = atoi(&(*b)[5])) ) { + if ( ax < bx ) return -1; + if ( ax == bx ) return 0; + if ( ax > bx ) return 1; + } + + return strncmp(*a, *b, 8); +} + +/* Find a FITS card in the header. + + #cardfind will use the index if is has been created otherwise + it searches sequentially through the header to find the card. + */ +FITSCard ft_cardfind(fits, key, add) + FITSHead fits; /* The FITS header to look in. */ + FITSCard key; /* The card keyword to lookup. */ + int add; /* If add is true the card will + be added to the header if it is + not found. + */ +{ + FITSCard card; + int match; + + if ( fits == NULL ) return NULL; + if ( key == NULL ) return NULL; + + if ( fits->index ) card = ft_cardfindidx(fits, key, &match); + else card = ft_cardfindseq(fits, key, &match); + + if ( !match && add ) + return ft_cardins(fits, key, card); + else return match ? card : NULL; +} + +/* Find a FITS card in the header using an index. + + If the header is not indexed an index is created for it. + */ +FITSCard ft_cardfindidx(fits, key, match) + FITSHead fits; + FITSCard key; + int *match; /* Returns true if the card found is + an exact match for the keyword requested. + */ +{ + FITSCard *base; + int length; + + int lo, hi, cut; + int i; + + if ( fits == NULL ) return NULL; + if ( key == NULL ) return NULL; + + base = fits->index; + length = ft_ncards(fits); + + lo = -1; + hi = length; + cut = length / 2; + + if ( !fits->index ) ft_headindex(fits); + + *match = 0; + while ( hi - lo > 1 ) { + if ( !(i = ft_compare((char **)&key, (char **)&base[cut])) ) { + *match = 1; + return base[cut]; + } + + if ( i < 0 ) { + hi = cut; + cut = (lo + hi) / 2; + } else { + lo = cut; + cut = (lo + hi) / 2; + } + } + + if ( !strncmp(key->c, base[cut]->c, 5) ) + return base[cut]; + + return NULL; +} + +/* Find a card in the FITS header using sequential search. + + If the requested card is a FITS indexed keyword and an exact match + is not found, the last card of that type is returned and + match is set to 0. + */ +FITSCard ft_cardfindseq(fits, key, match) + FITSHead fits; + FITSCard key; + int *match; +{ + FITSCard card; + FITSCard xnear = NULL; + + if ( fits == NULL ) return NULL; + if ( key == NULL ) return NULL; + + *match = 0; + for ( card = fits->cards; card != &fits->cards[fits->ncard]; card++ ) { + if ( !strncmp(key->c, card->c, 8) ) { + *match = 1; + return card; + } + if ( !strncmp(key->c, card->c, 5) + && (isdigit((unsigned int) (*card).c[5]) || (*card).c[5] == ' ' ) + && (isdigit((unsigned int) (*card).c[6]) || (*card).c[6] == ' ' ) + && (isdigit((unsigned int) (*card).c[7]) || (*card).c[7] == ' ' ) ) { + xnear = card; + } + } + + return xnear; +} + +FITSCard ft_cardfindblok(cards, key, match, nhist) + FITSCard cards; + FITSCard key; + int *match; + int *nhist; +{ + FITSCard card; + FITSCard xnear = NULL; + + if ( cards== NULL ) return NULL; + if ( key == NULL ) return NULL; + + *nhist = 0; + *match = 0; + for ( card = cards; card != &cards[FT_CARDS]; card++ ) { + if ( !strncmp(key->c, card->c, 8) ) { + *match = 1; + return card; + } + if ( !strncmp(key->c, card->c, 5) + && (isdigit((unsigned int) (*card).c[5]) || (*card).c[5] == ' ' ) + && (isdigit((unsigned int) (*card).c[6]) || (*card).c[6] == ' ' ) + && (isdigit((unsigned int) (*card).c[7]) || (*card).c[7] == ' ' ) ) { + xnear = card; + } + + if ( !strncmp(key->c, "HISTORY", 7) ) (*nhist)++; + } + + return xnear; +} |