ChE 117 Motivation Lots of Tools Can’t always use “Canned Programs” Excel • Mathematica MathCAD • Calculators Matlab • Polymath Can’t always use “Canned Programs” i.e. binary phase equilibria Data manipulation Process control and data acquisition Excel macro language (VBA) Web pages

Programming language: Visual Basic Interface with Excel (VBA) Similar to Fortran, C, C++, etc PC-based DAQ (data acquisition) and control High-level language (vs assembly) What is: Visual Basic .NET Computer interface List of instructions Contains Interpreter VB  machine language “on the fly”

Example: convert °F to °C or °C to °F What is a Program? Road map Set of instructions Good for repetition Input  Manipulate Output Example: convert °F to °C or °C to °F GUI ID Parts!

Example Program (manipulation) Average 3 numbers (10, 12, 15) Sub Avg() n1 = 10 n2 = 12 n3 = 15 avge = (n1 + n2 + n3) / 3 MsgBox avge End Sub

Decisions (“If” statements) Sub test2() label = "F" TF = 212 If label = "F" Then TC = (TF + 460) / 1.8 - 273 MsgBox TC End If End Sub “If – Then – Else - Endif Sub test3() label = "C" Tin = 100 If label = "F" Then Tout = (Tin + 460) / 1.8 - 273 Else Tout = (Tin + 273) * 1.8 - 460 End If MsgBox Tout End Sub

Loops (“If” statements) Add numbers 1 - 10 Sub looper1() sum = 1 n = 1 10 If n < 10 Then n = n + 1 sum = sum + n GoTo 10 End If MsgBox sum End Sub Loops (For – Next) Sub looper2() sum = 0 For i = 1 To 10 sum = sum + i Next i MsgBox sum End Sub

MS Excel & Visual Basic (VBA ~ VB.6) Excel Environment Worksheets Chart Sheets Workbook Modules sub & function procedures User Forms and objects (VBA code) VB Editor / Modules

Example Program (manipulation) Set up macro to calculate an average… use example as template. Run the macro Set up Form Button to run macro

Problem Solving Exercise (in groups) Set up macro to convert 100 kg to lbs or lbs to kg Display result in msgbox Run the macro Set up Form Button to run macro