Invalid Callee when using Matlab as a COM server

hello yall! I am trying to use matlab as a com server and I am getting the following error when using GetWorkspaceData()

Invalid callee. (Exception from HRESULT: 0x80020010 (DISP_E_BADCALLEE))

here is the code I am using

compiling with MS VStudio 2010 Professional, .NET 3.5

Private Sub RunAsServer() Matlab = New MLApp.MLApp Matlab.MaximizeCommandWindow() Matlab.Execute("cd c:\matlab") Matlab.Execute("a = 23;")

Dim thevar As Object = vbNull Try Matlab.GetWorkspaceData("a", "base", thevar) TextBoxBuffer.Text += thevar.ToString Catch ex As Exception MessageBox.Show(ex.Message) End Try

end Sub

[Janis Stolzenwald]

Wow, this question remained unanswered for 7yrs now. "MATLAB Answers" should be called "MATLAB solve it yourself please".

Same problem here. When calling matlab code in a c# loup it crashes after the first iteration with the error message above.

Answer 1

[Janis Stolzenwald]

I solved the problem in my case. Make sure to set the out variable back to null before passing it to Feval again.

Answer 2

[Andy]

Yeah, interesting @Janis Stolzenwald! Stumbled across the same problem ... thanks for sharing your solution 7 years later!

Did you manage to find also how to do *.Feval on function within function ... such as:

> t2.GetType()
[System.Double[,]]
> object results = null; matlab.Feval("cov", 1, out results, t2)
> results
object[1] { double[10, 10] { { 32.2, -34.599999999999994, 71.65, 1856.1999999999998, 94.25, 35.45, 92.2, 152.3, -138.3, 157 }, { -34.599999999999994, 2939.7999999999993, 2205.55, 18073.399999999998, -40.24999999999994, 261.15000000000003, 2120.3999999999996, 69.10000000000008, 1741.9, 3924 }, { 71.65, 2205.55, 3813.3, 15569.649999999998, 728.5, 39.14999999999998, 3730.3999999999996, 1317.1, 1380.65, 6561.5 }, { 1856.1999999999998, 18073.399999999998, 15569.649999999998, 395910.19999999995, 7004.25, 6084.450000000001, 17791.2, 13353.3, -6674.299999999999, 34322 }, { 94.25, -40.24999999999994, 728.5, 7004.25, 432.5, 61.750000000000014, 788, 729.5000000000001, -400.75, 1367.5 }, { 35.45, 261.15000000000003, 39.14999999999998, 6084.450000000001, 61.750000000000014, 123.2, 79.19999999999999, 119.8, -135.04999999999998, 189.5 }, { 92.2, 2120.3999999999996, 3730.3999999999996, 17791.2, 788, 79.19999999999999, 3677.2, 1419.8000000000002, 1159.2, 6482 }, { 152.3, 69.10000000000008, 1317.1, 13353.3, 729.5000000000001, ...
> object results = null; matlab.Feval("cov(cov)", 1, out results, t2)
System.Runtime.InteropServices.COMException: Undefined function 'cov(cov)' for input arguments of type 'double'.
  + System.RuntimeType.ForwardCallToInvokeMember(string, System.Reflection.BindingFlags, object, object[], bool[], int[], System.Type[], System.Type)
  + MLApp.MLAppClass.Feval(string, int, out object, object, object, object, object, object, object, object, object, object, object, object, object, object, object, object, object, object, object, object, object, object, object, object, object, object, object, object, object, object, object, object, object)
> 

did not expect the above to work, but not sure it's possible to compute "cov(cov(t2))" ... or any other combination of function of a function of a variable ... any ideas?