1 The Information School of the University of Washington Nov 20fit spreadsheets © 2006 University of Washington Structured Data INFO/CSE 100, Fall 2006 Fluency in Information Technology

2 The Information School of the University of Washington Nov 20fit spreadsheets © 2006 University of Washington Readings and References Reading »Fluency with Information Technology  Chapter 13, Introduction to Spreadsheets

3 The Information School of the University of Washington Nov 20fit spreadsheets © 2006 University of Washington Keeping track of things The need for keeping track of items spurned the invention of writing Today people still manually keep track of items usually in the form of lists »Shopping list »Christmas card addresses »Soccer team player roster »Runs Batted In (RBIs) milk eggs Cheetos...

4 The Information School of the University of Washington Nov 20fit spreadsheets © 2006 University of Washington tab-delimited text file example IL3RA-XD001NN IL3RA-XD002GG IL3RA-XD003GG IL3RA-XD004GG IL3RA-XD005GG IL3RA-XD006GG IL3RA-XD007GG IL3RA-XD008GG IL3RA-XD009AG IL3RA-XD010NN IL3RA-XD011NN IL3RA-XD012NN IL3RA-XD013GG IL3RA-XD014AG IL3RA-XD015NN IL3RA-XD016NN IL3RA-XD033AG IL3RA-XD034AG IL3RA-XD035GG IL3RA-XD036AG IL3RA-XD037AA IL3RA-XD038GG IL3RA-XD039GG IL3RA-XD040GG...

5 The Information School of the University of Washington Nov 20fit spreadsheets © 2006 University of Washington Text File Problems Lists get big quick - hard to find information? How do you make changes? How do you find duplicated information? How would you resort the information? How do you add a new column of information?

6 The Information School of the University of Washington Nov 20fit spreadsheets © 2006 University of Washington Spreadsheets Spreadsheets are a powerful abstraction for organizing data and computation A spreadsheet is a 2-dimensional array of cells... (Its 3D with multiple worksheets) »Rows or columns represent a common kind of data  They will be operated upon similarly  Adding more data of the same type means adding more rows or columns  Often spreadsheets contain numbers, but text-only spreadsheets are useful too!

7 The Information School of the University of Washington Nov 20fit spreadsheets © 2006 University of Washington Similar Ideas (To JavaScript) Spreadsheets are not so unusual... »The position (row/column) names the data, as with memory locations, variables, forms... »Setting a cell to a formula is an assignment statement with cells as variables »The formulas are expression »Functions are built-in spreadsheet programs

8 The Information School of the University of Washington Nov 20fit spreadsheets © 2006 University of Washington Spreadsheet Terminology row name column name cell formula column heading references cells L2-W2

9 The Information School of the University of Washington Nov 20fit spreadsheets © 2006 University of Washington Formulas

10 The Information School of the University of Washington Nov 20fit spreadsheets © 2006 University of Washington Using Fill

11 The Information School of the University of Washington Nov 20fit spreadsheets © 2006 University of Washington Relative and Absolute Addresses References to cells happen in one of two ways.. Relative or Absolute »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

12 The Information School of the University of Washington Nov 20fit spreadsheets © 2006 University of Washington Series Another handy feature of fill is that it can make it easy to make a series based on constraints »Fill Sunday=>Monday, Tuesday, Wednesday,.. »Fill 22 Feb=>23 Feb, 24 Feb, 25 Feb,... More generally »Series fill will even count using a constant »Counting by odd sizes: gives 1st two items

13 The Information School of the University of Washington Nov 20fit spreadsheets © 2006 University of Washington Sorting Data Sorting the data into some order is one of the most common operations »Numbers go numerically »Text goes alphabetically Data can be sorted in Ascending or Descending order Data can be sorted in second, third, or fourth order... »First one column, then the second column and so on...

14 The Information School of the University of Washington Nov 20fit spreadsheets © 2006 University of Washington Sort Example

15 The Information School of the University of Washington Nov 20fit spreadsheets © 2006 University of Washington Adding Functions

16 The Information School of the University of Washington Nov 20fit spreadsheets © 2006 University of Washington Importing/Exporting Data Importing data is one of the most common ways to create a spreadsheet Two ways to import data »Copy/paste »Import function Spreadsheets will do a lot of work to interpret data into a table format for importing »Import data from a text file »Import data from a web query »Among others...

17 The Information School of the University of Washington Nov 20fit spreadsheets © 2006 University of Washington Import Wizard

18 The Information School of the University of Washington Nov 20fit spreadsheets © 2006 University of Washington How to organize the data? Lists and Spreadsheets are often known as “flat files” (although a good 2D/3D spreadsheet isn't really flat) Common problems with the flat file format »Structural information is difficult to express »All processing of information is “special cased”  custom programs are needed »Information repeated; difficult to combine »Changes in format of one file means all programs that ever process that file must be changed  eg, adding ZIP codes

19 The Information School of the University of Washington Nov 20fit spreadsheets © 2006 University of Washington Library example from Access Database book, Steve Roman notice the redundancy

20 The Information School of the University of Washington Nov 20fit spreadsheets © 2006 University of Washington Why Study Databases? Databases solve those "flat file" problems Some of us want to compute All of us want access to information …  Much of the archived information is in tables  Databases enhance applications, e.g. Web  Once you know how to create databases, you can use them to personal advantage  Databases introduce interesting ideas

21 The Information School of the University of Washington Nov 20fit spreadsheets © 2006 University of Washington Homework 4 Due date moved: Now due Friday Dec 1st.