1 files changed, 19 insertions, 0 deletions
diff --git a/src/lin.c b/src/lin.c
new file mode 100644
index 0000000..2df6f28
--- /dev/null
+++ b/src/lin.c
@@ -0,0 +1,19 @@
+#include "lizfcm.h"
+#include <assert.h>
+
+Line *least_squares_lin_reg(Array_double *x, Array_double *y) {
+  assert(x->size == y->size);
+
+  uint64_t n = x->size;
+  double sum_x = sum_v(x);
+  double sum_y = sum_v(y);
+  double sum_xy = dot_v(x, y);
+  double sum_xx = dot_v(x, x);
+  double denom = ((n * sum_xx) - (sum_x * sum_x));
+
+  Line *line = malloc(sizeof(Line));
+  line->m = ((sum_xy * n) - (sum_x * sum_y)) / denom;
+  line->a = ((sum_y * sum_xx) - (sum_x * sum_xy)) / denom;
+
+  return line;
+}