Fluency with Information Technology INFO100 and CSE100 Katherine Deibel Katherine Deibel, Fluency in Information Technology1

 Powerful tools for managing data  Organization  Manipulation  Calculation  Visualization  High-level tool for programming  Think of spreadsheets as a handier interface for computing ideas than JavaScript is Katherine Deibel, Fluency in Information Technology2

row name column name cell formula column heading referenced cell L Katherine Deibel, Fluency in Information Technology3

 Variables: Cells are variables (contain data)  Expressions: Setting a cell to a formula is an (unevaluated) assignment statement  Functions and Parameters: Spreadsheets have built-in function  Arrays and IDs: The position (row/column) names the data  Iteration: Operating on all elements in a range as in =SUM(A1:A5) Katherine Deibel, Fluency in Information Technology4

 A spreadsheet is a 2-D array of cells  Multiple sheets make it 3-D  The idea is that the rows or columns represent a common kind of data  Adding more data of the same type means adding more rows or columns  Often spreadsheets contain numbers, but text-only spreadsheets are useful, too Katherine Deibel, Fluency in Information Technology5

 Reference to cells happens in 2 ways: Relative and Absolute (with $)  F2relative column, relative row  F$2relative column, absolute row  $F2absolute column, relative row  $F$2absolute column, absolute row  Relative references change when pasted/filled  Absolute references do not change Katherine Deibel, Fluency in Information Technology6

 Creating a discount table uses rel and abs refs  Consider store credit of $1 per $10 spent  $3 store credit for every 2 CDs (1 earns $1) =$B3/10 + (3/2)*C$2 =[B,myposition.row]/10 + (3/2)*[myposition.col,2] B Katherine Deibel, Fluency in Information Technology7

 Fill is a spreadsheet shortcut for copy-and-paste  Grab the fill tab with the cursor and pull in the direction to be pasted fill tab Katherine Deibel, Fluency in Information Technology8

 Spreadsheet cells contain one of three types of data  A number  A string  A formula  Essentially, almost anything can be put in a cell but it is only treated as one of the above Katherine Deibel, Fluency in Information Technology9

 Numbers are used to represent:  Numbers (duh)  Percentages  Fractions  Dates  Time  Many of the above depend on how the cell's display format is set Katherine Deibel, Fluency in Information Technology10

 When a cell contains data, it is displayed in two ways  The raw form  A formatted view  Formatting can be used to  Format dates  Add currency symbols  Scientific Notation Katherine Deibel, Fluency in Information Technology11

Katherine Deibel, Fluency in Information Technology12

May apply to other spreadsheet programs Consult your physician before stopping power use of Excel Offer not valid in Alaska Katherine Deibel, Fluency in Information Technology13

 The data in a spreadsheet can be manipulated using formulas  The value in H2 (selected cell) is the value in F2 times … the result is shown, but the cell has the formula Katherine Deibel, Fluency in Information Technology14

 One way to repeat the formula is to copy-and-paste Katherine Deibel, Fluency in Information Technology15

 The relative and absolute references work this way because they are in effect: =[myposition.col -2,myposition.row]* Katherine Deibel, Fluency in Information Technology16

ABC 1=C15=A1*B Katherine Deibel, Fluency in Information Technology17 Most spreadsheet programs will warn you against circular references and will not get caught in an infinite operation.

 Another handy property of fill is that it can make a series based on constants  Fill 0 Step 5  0, 5, 10, 15, 20, …  Fill 22 Feb  23 Feb, 24 Feb, 25 Feb, …  More generally  Series fill will even count using a constant  Counting by odd sizes: give 1st two items Katherine Deibel, Fluency in Information Technology18

 Chapter 15 Case Study – Travel Costs  This chapter guides you through several other power features of Excel  Conditional Formatting  Filtering Katherine Deibel, Fluency in Information Technology19

Calculations, Formulas, Charts, Etc Katherine Deibel, Fluency in Information Technology20 Mommy plays with Excel instead of me…

 Spreadsheets come with built-in functions for many purposes:  Basic math functions (ABS, FLOOR, EXP)  Statistics (AVERAGE, MEDIAN)  String manipulation (FIND, LEN  Logic (IF, AND, NOT)  And many more Katherine Deibel, Fluency in Information Technology21

 When you enter a = into the edit bar, you can click on the function button  This brings up a list of functions for you to browse through  Each function also has help files and demos associated with it Katherine Deibel, Fluency in Information Technology22

 Interactive windows help you fill in formula parameters Katherine Deibel, Fluency in Information Technology23

 There's a CONCATENATE function, but it's easier to just use the & symbol  ="I want a " & 4.0 & " GPA" will output: I want a 4.0 GPA  To include a double quote in a string, use two: "" Katherine Deibel, Fluency in Information Technology24

 Visualizations help with communicating large amounts of data  Lots of room for flexibility and creativity  Entire course in itself  Good place to blaze away and explore  Plenty of good tutorials online  One of my favorites is: Katherine Deibel, Fluency in Information Technology25

 Spreadsheets are great because they have lots of cells  Spread out your calculations  As they said in elementary school math… SHOW YOUR WORK!! Katherine Deibel, Fluency in Information Technology26

 Let's calculate something complex  Yes, Excel has a built-in function for this (STDEV), but let's do this  By the way, μ is the average of the N x's Katherine Deibel, Fluency in Information Technology27

 Excel VBA is a programming language  Visual Basic for Applications  Lets you write event handlers, macros, your own formulas  Object-oriented like JavaScript  Has its own idiosyncrasies  Large user community with online tutorials and help forums Katherine Deibel, Fluency in Information Technology28

 Spreadsheets are powerful tools  One of the best tools for the digerati  Easy access to programming  Spreadsheets are often the easiest way to make a computer solve your problem if the software for that problem doesn’t already exist Katherine Deibel, Fluency in Information Technology29