Ironpython: Message: Expected C_double, Got C_double_array_3

I’m currently developing a script using the python script editor in Rhino. As I’m currently working in a Windows machine, the script editor uses IronPython as language. In the

Solution 1:

I've found when working with IronPython you need to explicitly cast the "Array of three doubles" to a "Pointer to double". So if you're using Grasshopper with the Strand7 / Straus7 API you will need to add an extra bit like this:

import St7API
import ctypes

# Make the pointer conversion functions
PI = ctypes.POINTER(ctypes.c_long)
PD = ctypes.POINTER(ctypes.c_double)

XYZType = ctypes.c_double*3
XYZ = XYZType()
node_num = 1

# Cast arrays whenever you pass them to St7API from IronPython
St7API.St7GetNodeXYZ(1, node_num, PD(XYZ))

I don't have access to IronPython or Strand7 / Straus7 at the moment but from memory that will do it. If that doesn't work for you you can email Strand7 Support - you would typically get feedback on something like this within a day or so.