diff options
Diffstat (limited to 'libcrystfel')
| -rw-r--r-- | libcrystfel/src/utils.h | 20 |
1 files changed, 20 insertions, 0 deletions
diff --git a/libcrystfel/src/utils.h b/libcrystfel/src/utils.h index b75693db..1adb69e6 100644 --- a/libcrystfel/src/utils.h +++ b/libcrystfel/src/utils.h @@ -139,6 +139,11 @@ static inline double modulus(double x, double y, double z) return sqrt(x*x + y*y + z*z); } +static inline double modulus2d(double x, double y) +{ + return sqrt(x*x + y*y); +} + static inline double modulus_squared(double x, double y, double z) { return x*x + y*y + z*z; } @@ -165,6 +170,21 @@ static inline double angle_between(double x1, double y1, double z1, return acos(cosine); } +/* Answer in radians */ +static inline double angle_between_2d(double x1, double y1, + double x2, double y2) +{ + double mod1 = modulus2d(x1, y1); + double mod2 = modulus2d(x2, y2); + double cosine = (x1*x2 + y1*y2) / (mod1*mod2); + + /* Fix domain if outside due to rounding */ + if ( cosine > 1.0 ) cosine = 1.0; + if ( cosine < -1.0 ) cosine = -1.0; + + return acos(cosine); +} + static inline int within_tolerance(double a, double b, double percent) { double tol = fabs(a) * (percent/100.0); |