diff options
| -rw-r--r-- | libcrystfel/src/integer_matrix.c | 58 |
1 files changed, 24 insertions, 34 deletions
diff --git a/libcrystfel/src/integer_matrix.c b/libcrystfel/src/integer_matrix.c index 5aefb958..477d16a6 100644 --- a/libcrystfel/src/integer_matrix.c +++ b/libcrystfel/src/integer_matrix.c @@ -235,6 +235,28 @@ static IntegerMatrix *delete_row_and_column(IntegerMatrix *m, } +static signed int cofactor(IntegerMatrix *m, + unsigned int i, unsigned int j) +{ + IntegerMatrix *n; + signed int t, C; + + n = delete_row_and_column(m, i, j); + if ( n == NULL ) { + fprintf(stderr, "Failed to allocate matrix.\n"); + return 0; + } + + /* -1 if odd, +1 if even */ + t = (i+j) & 0x1 ? -1 : +1; + + C = t * intmat_det(n); + intmat_free(n); + + return C; +} + + /** * intmat_det: * @m: An %IntegerMatrix @@ -258,23 +280,7 @@ signed int intmat_det(IntegerMatrix *m) i = 0; /* Fixed */ for ( j=0; j<m->cols; j++ ) { - signed int C; - IntegerMatrix *n; - signed int t; - - n = delete_row_and_column(m, i, j); - if ( n == NULL ) { - fprintf(stderr, "Failed to allocate matrix.\n"); - return 0; - } - - /* -1 if odd, +1 if even */ - t = (i+j) & 0x1 ? -1 : +1; - - C = t * intmat_det(n); - intmat_free(n); - - det += intmat_get(m, i, j) * C; + det += intmat_get(m, i, j) * cofactor(m, i, j); } @@ -293,23 +299,7 @@ static IntegerMatrix *intmat_cofactors(IntegerMatrix *m) for ( i=0; i<n->rows; i++ ) { for ( j=0; j<n->cols; j++ ) { - signed int C; - IntegerMatrix *M; - signed int t; - - M = delete_row_and_column(m, i, j); - if ( M == NULL ) { - fprintf(stderr, "Failed to allocate matrix.\n"); - return 0; - } - - /* -1 if odd, +1 if even */ - t = (i+j) & 0x1 ? -1 : +1; - - C = t * intmat_det(M); - intmat_free(M); - - intmat_set(n, i, j, C); + intmat_set(n, i, j, cofactor(m, i, j)); } } |