Third-Party Library Functions

【Excel VBA】

Excel VBA can use third-party library functions. After creating or obtaining a third-party library, in the Excel VBA programming environment, select Tools → References to open the References dialog box, as shown in Figure 10-1. Find the library to be referenced in the list, or click the Browse button to locate the library file, then click OK to complete the reference. The referenced third-party library can be viewed using the Object Browser.

Figure 10-1 "References" Dialog Box

To introduce vector and matrix calculations in VB, the author once wrote a dynamic link library Math3D.dll in VB. Below, we reference it in the Excel VBA programming environment and encode tests. The file path is Samples\ch10\Excel VBA\ThirdPartyLibraryFunctions.xlsm. Math3D.dll is in the same directory. The following code requires referencing it first.

code.vba 
Sub Test()
    Dim vctFirst As Vector3D
    Dim vctSecond As Vector3D
    Dim mtxFirst As Matrix3D
    Dim mtxSecond As Matrix3D
    Set vctFirst = New Vector3D
    Set vctSecond = New Vector3D
    Set mtxFirst = New Matrix3D
    Set mtxSecond = New Matrix3D

    ' First vector
    vctFirst.x = 10#
    vctFirst.y = 78.5
    vctFirst.Z = 102.9

    ' Second vector
    vctSecond.x = 109.2
    vctSecond.y = 82.5
    vctSecond.Z = 180.8

    ' Output the first and second vectors in the Immediate Window
    Dim strFirst As String
    Dim strSecond As String
    strFirst = "First vector: " & Str(vctFirst.x) & " " & Str(vctFirst.y) & " " & Str(vctFirst.Z)
    strSecond = "Second vector: " & Str(vctSecond.x) & " " & Str(vctSecond.y) & " " & Str(vctSecond.Z)
    Debug.Print
    Debug.Print strFirst
    Debug.Print strSecond
    Debug.Print

    ' Length of the first vector
    Dim strLen As String
    strLen = "Length of the first vector: " & vctFirst.GetLength
    Debug.Print strLen

    ' Vector operations
    Dim vctAdd As Vector3D
    Dim vctSub As Vector3D
    Dim dblMulDot As Double
    Dim vctMulCro As Vector3D
    Dim vctDev As Vector3D
    Set vctAdd = vctFirst.Add(vctSecond)
    Set vctSub = vctFirst.Subtract(vctSecond)
    dblMulDot = vctFirst.MultDot(vctSecond)
    Set vctMulCro = vctFirst.MultCross(vctSecond)
    Set vctDev = vctFirst.Devide(2)
    Set vctDev = vctFirst.Devide(2)

    ' Output operation results
    Dim strAdd As String
    Dim strSub As String
    Dim strMulDot As String
    Dim strMulCro As String
    Dim strDev As String
    strAdd = "Vector sum: " & Str(vctAdd.x) & " " & Str(vctAdd.y) & " " & Str(vctAdd.Z)
    strSub = "Vector difference: " & Str(vctSub.x) & " " & Str(vctSub.y) & " " & Str(vctSub.Z)
    strMulDot = "Vector dot product: " & Str(dblMulDot)
    strMulCro = "Vector cross product: " & Str(vctMulCro.x) & " " & Str(vctMulCro.y) & " " & Str(vctMulCro.Z)
    strDev = "First vector divided by 2: " & Str(vctDev.x) & " " & Str(vctDev.y) & " " & Str(vctDev.Z)
    Debug.Print strAdd
    Debug.Print strSub
    Debug.Print strMulDot
    Debug.Print strMulCro
    Debug.Print strDev
End Sub

Running the procedure outputs the calculation results in the Immediate Window.

code.vba 
First vector: 10 78.5 102.9
Second vector: 109.2 82.5 180.8
Length of the first vector: 129.81009205759
Length of the first vector: 129.81009205759

【Python】

In Python, to reference third-party libraries (also called third-party modules or packages), you first need to install the library, then import it in the code that uses it. NumPy and pandas introduced in Chapter 7 are both third-party packages; readers can refer to the corresponding content to learn their usage.