how to specify only calculate M2, S2, K1, O1

[gdshen]

I am wondering how to specify to calculate only a small number tides, instead of many tides?

[efiring]

From the docstring for solve(), this describes the keyword argument you can use to specify the constituents you want to include in the solution:

    constit : {'auto', array_like}, optional
        List of strings with standard letter abbreviations of
        tidal constituents; or 'auto' to let the list be determined
        based on the time span.

[gdshen]

Thanks very much. This solves my problems.