笛卡尔坐标转换为极坐标。
cartToPolar(...)
cartToPolar(x, y[, magnitude[, angle[, angleInDegrees]]]) -> magnitude, angle
. @brief Calculates the magnitude and angle of 2D vectors.
.
. The function cv::cartToPolar calculates either the magnitude, angle, or both
. for every 2D vector (x(I),y(I)):
. \f[\begin{array}{l} \texttt{magnitude} (I)= \sqrt{\texttt{x}(I)^2+\texttt{y}(I)^2} , \ \texttt{angle} (I)= \texttt{atan2} ( \texttt{y} (I), \texttt{x} (I))[ \cdot180 / \pi ] \end{array}\f]
.
. The angles are calculated with accuracy about 0.3 degrees. For the point
. (0,0), the angle is set to 0.
. @param x array of x-coordinates; this must be a single-precision or
. double-precision floating-point array.
. @param y array of y-coordinates, that must have the same size and same type as x.
. @param magnitude output array of magnitudes of the same size and type as x.
. @param angle output array of angles that has the same size and type as
. x; the angles are measured in radians (from 0 to 2\*Pi) or in degrees (0 to 360 degrees).
. @param angleInDegrees a flag, indicating whether the angles are measured
. in radians (which is by default), or in degrees.
. @sa Sobel, ScharrcartToPolar(...)
cartToPo
