my program generates 2D contours using scipy.spatial ConvexHull. I get the same error for any hull

Example

ph=array([[0.16416803, 0.20534728],
         [0.54442649, 0.18041865],
         [0.94021202, 0.73884783],
         [0.88563465, 0.87819372],
         [0.44831134, 0.88884114],
         [0.27379361, 0.83314181],
         [0.23401572, 0.73220657]])

Here’s the error message

(area, triangle) = cv2.minEnclosingTriangle(np.array(ph))
cv2.error: OpenCV(4.10.0) D:aopencv-pythonopencv- pythonopencvmodulesimgprocsrcconvhull.cpp:143: error: (-215:Assertion failed) total >= 0 && (depth == CV_32F || depth == CV_32S) in function ‘cv::convexHull’
`

Any suggestions for this beginner?