Spreadsheets Foundation Computing All those who believe in psycho kinesis, raise my hand.

2 of 38 Quiz  What is an interface?

3 of 38 Quiz (2)  What is special about the USB interface?

4 of 38 Why Spreadsheets?  Word processor Processing words, layout of text, spell check  Calculator Arithmetic calculations  Spreadsheet Tabulating data and calculations on the data, analyse and present data

5 of 38 Why Spreadsheets? (2)  Collating and processing numeric data, eg Student marks Results of an experiment  Financial analysis, eg Budgets Understanding financial results  Visualizing data, trends, etc Charts  Schedules, timetables, etc

6 of 38 History  Idea: Dan Bricklin (while a Masters student at Harvard)  VisiCalc (1979) Dan Bricklin + Bob Frankston Apple II  MS Excel  OpenOffice Spreadsheets

7 of 38 What is a spreadsheet?  Developed to do financial computations in a page layout  Similar to a bookkeeper’s ledger Rows and columns of numerical data  But different Stores formulas as well

8 of 38  Terminology In Excel, a spreadsheet is called a worksheet An Excel file contains a workbook that is a number of worksheets Each worksheet is a huge grid of cells Each cell is identified by its column (a letter) and its row (a number), eg A1 (example) What is a spreadsheet? (2)

9 of 38 See also short video “workbook” from lecture webpage

10 of 38 The cell  Each cell has a content, which can be a constant such as a label (text) or a value a formula that calculates the value  and a format, which controls how the content is displayed  An operation applies to a single cell, or to a range of cells, such as a complete row or column

11 of 38 The cell (2)  Content Labels give numbers meaning

12 of 38 The cell (2)

13 of 38 The cell (2)  Content Labels give numbers meaning

14 of 38 The cell (3) Values, eg  Numbers  Percentages  Currency (money values)  Dates  Times  Text Type determined by how written or manually set (example) Formulas (later)

15 of 38 See video “Book2“ on lecture webpage

16 of 38 The cell (3) Values, eg  Numbers  Percentages  Currency (money values)  Dates  Times  Text Type determined by how written or manually set (example) Formulas (later)

17 of 38 The cell (4)  Format Font, size, colour, (text and background) (example) Shading, borders You can also control  Column width  Row height (example)  Merged cells

18 of 38 See video “format” on lecture webpage

19 of 38 The cell (4)  Format Font, size, colour, (text and background) (example) Shading, borders You can also control  Column width  Row height (example)  Merged cells

20 of 38 expenses.xls Using Spreadsheets Merged cells Active cell D8 labels values (currency) values (dates) Formula result Formula

21 of 38 Using Spreadsheets (2)  Cell Reference Single cell: Row and column, eg A1  Range of cells Rectangular group of cells, eg A1:A3, or A1:B2 (top left: bottom right)

22 of 38 Using Spreadsheets (3)  Select a range by Click-dragging across the cells SHIFT-clicking on the corner cells Clicking on an entire row/column Typing in the addresses of corner cells, separated by a colon

23 of 38 Using Spreadsheets (4)  When multiple cells are selected, we can Change the format for all these cells Merge these cells Copy/cut the contents and paste elsewhere Delete the contents of all these cells (example)

24 of 38 Using Spreadsheets (5)  For a complete row/column, we can Delete the entire row/column Insert a new row/column before/after Change column width or row height

25 of 38 Formulas  Formulas Two views  Formula  Value in cell To see a cell's formula, make it the active cell then look at the formula bar Start with = Example =A1

26 of 38 A simple formula

27 of 38 Formulas  Formulas Two views  Formula  Value in cell To see a cell's formula, make it the active cell then look at the formula bar Start with = Example =A1

28 of 38 Formulas (2)  Arithmetic operations Example =A1+1  (Compounding interest) =A1/A2 divide / =A1*A2 times* =A1-A2 minus- =A1+A2 plus+ ExampleMeaning Arithmetic Operator

29 of 38 Interest example

30 of 38 Formulas (2)  Arithmetic operations Example =A1+1  (Compounding interest) =A1/A2 divide / =A1*A2 times* =A1-A2 minus- =A1+A2 plus+ ExampleMeaning Arithmetic Operator

31 of 38 Functions  Examples =AVERAGE(A1:A3) =SUM(A1:A3) =COUNT(A1:A3) =IF(A1>0,"Positive","Negative")  Test with true and false options There are many more!!! (example)

32 of 38 Functions

33 of 38 Sum example

34 of 38 Functions (2)  Predefined in spreadsheet application  Perform common tasks  Arguments as input value cell reference cell range results from other functions

35 of 38 IF function example (1)

36 of 38 If function example (2)  If function within a function

37 of 38 Functions (3)  Example You may get an exam question like this! What value will appear in cell C3?

38 of 38 If function again

39 of 38 Copying Formulas  Often in a table we find that a range of cells, eg. a column, share the same formula.  There is a shorthand way of doing this: Enter the formula in the first cell Use the fill handle to drag the formula into adjacent cells, or Select the range of cells and use the fill menu or fill keyboard shortcut. (example)

40 of 38 See video “IF copy” on lecture webpage

41 of 38 See video “absolute reference” on lecture webpage

42 of 38 Copying Formulas (2)  Sometimes filling a formula doesn't do what we expect. Why? A formula contains addresses of other cells. Normally these are relative addresses which get altered when we fill the formula. Sometimes we want these to be absolute addresses so that they don't change when we fill the formula. Put $ into addresses. (example)

43 of 38  Absolute addresses Fixed column$A1 Fixed rowA$1 Both fixed$A$1 Copying Formulas (3)

44 of 38 Open file “abs_rel_example” on lecture webpage

45 of 38 Open file “abs_rel_example” on lecture webpage

46 of 38 Open file “abs_rel_example” on lecture webpage

47 of 38 Open file “abs_rel_example” on lecture webpage

48 of 38 Charts  Used to visualize results Bar/Columncomparison of values Linetrend over time Pieproportions Chart Wizard Highlight values and labels (hold control) Start wizard (examples column and pie chart)

49 of 38 Charts (2)  Can include a spreadsheet into another document, eg. Word, PowerPoint  Use "Paste Special" to choose between: Embed a COPY of the spreadsheet into the document or Insert a LINK to the spreadsheet into the document  Consider portability issues with Object Linking and Embedding  (example)

50 of 38 Charts (3)  There are a wide variety of graphs and charts available in Excel  FIRST decide what you want to show with a chart or graph!  Understand what your data means!  Use the Chart wizard to build your chart or graph  Play with alternatives but make sure your chart or graph makes sense!

51 of 38 Charts (4)  Axis scale, labels etc. Note that an axis can have a date/time scale  Gridlines  Legend for categories or lines  Actual data value or labels on the chart  Colours, patterns, 3D effects  Chart title  In own worksheet or superimposed on an existing worksheet

52 of 38 Printing and page setup  Can include headers and footers  Can force a worksheet to fit on a single page or one page wide  Can print just a range of cells on a worksheet  Can choose to print or not print grid lines  Can repeat selected rows (or columns) on every page, eg. headings  Use PREVIEW!  Can rename sheets

53 of 38 Final word of warning  Spreadsheets are a wonderful aid to analysing and understanding data  HOWEVER, it is very easy to make an error in a spreadsheet formula and to not realise that it is telling you the wrong answer  Always check a sample of your spreadsheet  Calculations by hand using a calculator!