{"name":"regression","title":"Linear Regression (least squares)","category":"statistics","description":"Best-fit slope, intercept, r^2 and an optional prediction from paired x/y data.","price_usd":0.002,"input_schema":{"type":"object","properties":{"x":{"type":"array","description":"Array of x values (length >= 2)"},"y":{"type":"array","description":"Array of y values (same length as x)"},"predict_x":{"type":"number","description":"Optional x to predict y for"}},"additionalProperties":false,"required":["x","y"]}}