using System;

namespace Python.Runtime

{

public class Matplotlib

{

public static void Initialize(string backend = null)

{

np = Py.Import("numpy");

matplotlib = Py.Import("matplotlib");

if (!String.IsNullOrEmpty(backend))

{

// backend must be set before pylab be imported

// It can not be changed after pylab be imported

PythonEngine.Exec($"import matplotlib;matplotlib.use('{backend}')");

}

plt = Py.Import("matplotlib.pylab");

PltFigureType = plt.GetAttr("Figure").Handle;

var io = Py.Import("io");

BytesIO = io.GetAttr("BytesIO");

PythonEngine.Exec("import matplotlib;print(matplotlib.get_backend())");

}

internal static PyObject np;

internal static PyObject matplotlib;

internal static PyObject plt;

internal static IntPtr PltFigureType;

internal static PyObject BytesIO;

public static byte[] SaveFigureToArray(PyObject fig, int dpi = 200, string format = "png")

{

if (fig.GetPythonType().Handle != PltFigureType)

{

throw new Exception("object is not a matplotlib Figure");

}

dynamic _np = np;

//buf = io.BytesIO()

dynamic buf = BytesIO.Invoke();

//fig.savefig(buf, dpi=__dpi__, format='png')

fig.InvokeMethod("savefig", new PyTuple(new PyObject[] { buf }), Py.kw("dpi", dpi, "format", format));

var buf_out = _np.array(buf.getbuffer(), Py.kw("dtype", Numpy.GetNumpyDataType(typeof(byte))));

var arr = Numpy.ToArray(buf_out);

return (byte[])arr;

}

public static string get_backend()

{

return matplotlib.InvokeMethod("get_backend").ToString();

}

}

}