[Q] Serious API troubling between Python and Mathcad prime - SetMatrixElement(), GetMatrixElement()

[JW1]

Dear sir,

Now I am solving a design optimization problem using Mathcad prime 6.0 through python API. I uses comtypes library to deal with API programming in my Python code.

In python code, I can set a single variable easily and vice verse. However, I could not set a matrix and get it from Mathcad.

I really love to exchange variables which whether it is a real single variable or matrix between Python and Mathcad.

I could not find any solution method for this trouble.

Please help me with this issue. I really want to make them exchangeable for reproducible research work. It is not commercial but academic.

With my best regards,

JW

---------------------------------------------------------------------------------------

The following is the python code to call and set matrix in Mathcad. Two functions are defined. The first(set_element) is  to set the elements of the matrix in Mathcad but the second(get_element) is to get the element of the matrix from Mathcad.

---

   import comtypes.client as CC

   import comtypes

    def set_element(self, row_index, column_index, value):

        """ Sets the value of an element in the Matrix """

        if self.object is not None:

            try:

                row, col = int(row_index), int(column_index)

                self.object.SetMatrixElement(row, col, value)

            except ValueError:

                raise ValueError("Matrix maths can only use numerical values")

            except:

                raise Exception("COM Error setting element value")  # Hidden for above @FIXME

        else:

            raise TypeError("Matrix must first be created")

    def get_element(self, row_index, column_index):

        """ Fetches the value of an element in the Matrix """

        if self.object is not None:

            try:

                row, col = int(row_index), int(column_index)

                self.object.GetMatrixElement(row, col)

            except ValueError:

                raise ValueError("Matrix maths can only use numerical values")

            except:

                raise Exception("COM Error fetching element value")

        else:

            raise TypeError("Matrix must first be created")

[Werner_E]

I remember there were a few threads in this forum about exchanging matrices via the API in the past but I am not sure if there ever was a satisfying solution. You may try the search function in the forum to find those threads.

While not specifically covering python, maybe this post can be of help: https://community.ptc.com/t5/PTC-Mathcad/Using-Matrix-with-Prime-3-1-API/m-p/313195/highlight/true#M122230

[JW1]

I really appreciate it.  I will look at it.

[JW1]

Is there anybody who can reach https://www.ptc.com/en/support/article/CS301830?

The name of article is 'Article - CS301830 How to set a matrix element value using API SetMatrixElement() and SetMatrixValue() in Mathcad Prime'.

It is the right thing for me.

Please help me look at the article.

JW

[Werner_E]

Here you are, but the "article" just consists of the code example which you can also find in the thread I linked to in my first answer.

------------------------------------------------------- snip -------------------------------------------------

How to set a matrix element value using API SetMatrixElement() and SetMatrixValue() in Mathcad Prime

Modified: 28-Feb-2019   

• Available in: English

Applies To

• Mathcad Prime 3.1 to 5.0

• API

Description

• How to set a matrix element value using API SetMatrixElement() and SetMatrixValue()

Resolution

• Code example:

var appCreate = new Ptc.MathcadPrime.Automation.ApplicationCreatorClass();

Ptc.MathcadPrime.Automation.ApplicationCreator app;
app = (Ptc.MathcadPrime.Automation.ApplicationCreator)appCreate;

Ptc.MathcadPrime.Automation.IMathcadPrimeWorksheet3 ws;
ws = (Ptc.MathcadPrime.Automation.IMathcadPrimeWorksheet3) app.Open(WorksheetFileName);
int numRows = // whatever;
int numCols = // whatever;

Ptc.MathcadPrime.Automation.IMathcadPrimeMatrix matrixValue = (Ptc.MathcadPrime.Automation.IMathcadPrimeMatrix) ws.CreateMatrix(numRows, numCols);

for (int j = 1; j <= numRows; j++)
{
  for (int k = 1; k <= numCols; k++)
  {
  double valueArg = // In my case I fetch valueArg from some other system here
  matrixValue.SetMatrixElement(j - 1, i - 1, valueArg);
  }
}
string aliasArg = // whatever
string unitsArg = // whatever; 
ws.SetMatrixValue(aliasArg, matrixValue, unitsArg);

[JW1]

It is ridiculous.  Even though I coded like the c++ in the above, it still does not work. I do not know where I start from.

--------------------

<Functions>

    def create_matrix(self, rows, columns):

        """ Creates a Mathcad matrix """

        try:

            rows, columns = int(rows), int(columns)

            self.shape = (rows, columns)

            self.object = self.__ws.CreateMatrix(rows, columns)

            return True

        except ValueError:

            raise ValueError("Matrix dimensions must be integers")

            return False

        except:

            raise Exception("COM Error creating Mathcad matrix")

            return False

    def set_element(self, row_index, column_index, value):

        """ Sets the value of an element in the Matrix """

        if self.object is not None:

            try:

                row, col = int(row_index), int(column_index)

                self.object.SetMatrixElement(row, col, value)  # @FIXME

            except ValueError:

                raise ValueError("Matrix maths can only use numerical values")

            except:

                raise Exception("COM Error setting element value")  # Hidden for above @FIXME

        else:

            raise TypeError("Matrix must first be created")

-----------------------

<Main>

    A = Matrix()

    A.create_matrix(2,2) 

    A.set_element(1,1,3.0)

--------------------

<Error messege>

Loading Mathcad

Traceback (most recent call last): File "//Mac/Home/Downloads/MathcadPy-master/MathcadPy/Application.py", line 361, in <module> A.set_element(1,1,3.0) File "//Mac/Home/Downloads/MathcadPy-master/MathcadPy/Application.py", line 312, in set_element self.object.SetMatrixElement(row, col, value) # @FIXME OSError: exception: access violation writing 0x0000000000000001