sqrt

sqrt(X)

Return the square root of each element in X. The data type of the result is always DOUBLE.

Difference from Python’s numpy.sqrt: Both functions calculate square roots. DolphinDB’s sqrt returns DOUBLE values, and negative inputs produce NULL values. numpy.sqrt is a ufunc. Negative real inputs usually return nan, and complex inputs can return complex results.

X is a scalar/vector/matrix.

A DOUBLE scalar, vector, or matrix.

sqrt(4 16 -4 NULL);
// output: [2,4, , ]

typestr(sqrt(4));
// output: DOUBLE