Unit 5: Visualization of Data M5-4: Organizing Many Categorical Variables

Transcription

1 Unit 5: Visualization of Data M5-4: Organizing Many Categorical Variables Outline: Introduction Learning Objectives Contents Definitions Creating a Pivot Table Creating a PivotTable in Excel 2013 Working with PivotTable Exercises/Self-Test 1

2 Introduction: Learning Objectives The purpose of this module is to help students learn in a clear, concise, and easy way what is the multidimensional contingency table, why it is used, and how and where to apply it. 2

3 Definition: Categorical Variable Categorical Variable : In statistics, a categorical variable is a variable that can take on one of a limited, and usually fixed, number of possible values. In computer science and some branches of mathematics, categorical variables are referred to as enumerations or enumerated types. Categorical data is the statistical data type consisting of categorical variables or of data that has been converted into that form, for example as grouped data. More specifically, categorical data may derive from either or both of observations made of qualitative data, where the observations are summarized as counts or cross tabulations, or of quantitative data, where observations might be directly observed counts of events happening or they might counts of values that occur within given intervals. Often, purely categorical data are summarized in the form of a contingency table. Source: Basic Business Statistics Concepts and Applications, 13rd Edition, Berenson/Levine/Szabat 1

4 Definition: Power Pivot Power Pivot is an Excel 2013 add-in you can use to perform powerful data analysis and create sophisticated data models. With Power Pivot, you can mash up large volumes of data from various sources, perform information analysis rapidly, and share insights easily. In both Excel and in Power Pivot, you can create a Data Model, a collection of tables with relationships. The data model you see in a workbook in Excel is the same data model you see in the Power Pivot window. Any data you import into Excel is available in Power Pivot, and vice versa. Reference: powerful-data-analysis-and-data-modeling-in-excel- HA aspx?CTT=5&origin=HA

5 Definition: Pivot Table Pivot Table: In data processing, a pivot table is a data summarization tool found in data visualization programs such as spreadsheets or business intelligence software. Among other functions, a pivot-table can automatically sort, count total or give the average of the data stored in one table or spreadsheet. It displays the results in a second table (called a "pivot table") showing the summarized data. Pivot tables are also useful for quickly creating unweighted cross tabulations. The user sets up and changes the summary's structure by dragging and dropping fields graphically. This "rotation" or pivoting of the summary table gives the concept its name. Source: Basic Business Statistics Concepts and Applications, 13rd Edition, Berenson/Levine/Szabat 3

6 Characteristics of a PivotTable in Excel 2013: Creating a PivotTable in Excel 2013 A PivotTable allows you to summarize, analyze, and explore large amounts of data Data can be dynamically arranged to view it from different angles One column must have duplicate values to create categories for organizing and summarizing data Another column must have numeric values One can create a PivotTable by clicking PivotTable in the Tables group on the Insert tab Working with PivotTable, An Example: 1. Introduction 2. Create a PivotTable 3. Create a Calculated Field 4. Modify a PivotTable 5. Change Values Field 6. Sort, Filter, and Slice a PivotTable 7. Format a PivotTable 4

7 1. An Introduction Estimates Production Costs per Products [$ per pint] # Products Production Costs (Variable Costs), per pint Notes Materials Labor Others Ingredients (*) CO2 + H2O 1 Pilsner All-Malt Beer $0.35 $ $0.05 $ $0.25 $ $0.35 (**); (****) 2 Bavarian Lager All-Malt Beer $0.35 $ $0.05 $ $0.25 $ $0.35 (**); (****) 3 Light Wheat Beer $0.33 $ $0.05 $ $0.25 $ $0.35 (***); (****) 4 Red Wheat Beer $0.33 $ $0.05 $ $0.25 $ $0.35 (***); (****) 5 Pale Ale Beer $0.33 $ $0.05 $ $0.25 $ $0.35 (***); (****) 6 Nut Brown Ale $0.33 $ $0.05 $ $0.25 $ $0.35 (****) 7 Bock Dark Beer $0.33 $ $0.05 $ $0.25 $ $0.35 (***); (****) 8 Stout Beer $0.33 $ $0.05 $ $0.25 $ $0.35 (****) 9 Selection of 17 more products $0.33-$0.35 $ $0.05 $ $0.25 $ $0.35 (****) This example is used in the graduate course BU MET AD715 Quantitative & Qualitative Decision Making, and is part of the Business Running Case Investing in New BrewPub? Zlatev, Notes: (*) The cost per product is based on the price of a delivered, complete set of ingredients (one supply batch kit is required for the production of one 155 gallon tank of beer) (**) Products recommended for both direct sales in the existing restaurant/tavern AND as draught beer tapped in kegs (wholesale) (***) Products recommended for direct sales in the existing restaurant/tavern (****) Cost per products for CO2, H2O, Labor, and Others varies for different locations 5

8 2. Create a PivotTable Data Preparation Dataset of the Example: Product ID Distribution Name Materials Labor Others Overall Prices Quantity BR01-01, [retail] Pilsner $0.84 $ BR01-02, [retail] Bavarian Lager $0.84 $ BR01-03, [retail] Light Wheat $0.84 $ BR01-04, [retail] Red Wheat $0.84 $ BR01-05, [retail] Pale Ale $0.84 $ BR01-06, [retail] Bock Dark $0.84 $ BR01-07, [wholesale] Pilsner $0.84 $ BR01-08, [wholesale] Bavarian Lager $0.84 $ BR01-10, [retail] Nut Brown Ale $0.84 $ BR01-11, [retail] Special Offer $0.26 $0.84 $

9 2. Create a PivotTable Choose the data and click on PivotTable under Insert menu 7

10 3. Create a Calculated Field Introduction to Calculated Field Calculated field: I. Is a user-defined field II. Does not exist in the original dataset Use basic arithmetic operations, but not cell references or range names Use built-in calculations 8

11 3. Create a Calculated Field Insert Calculated Field under Field, Items, & Sets which is listed under Analyze menu Create Overall Cost =Overall*Quantity; Overall Contribution =Overall*Prices. 9

12 4. Modify a PivotTable Modify a PivotTable Add, remove, or rearrange fields to get a different perspective of the data Be careful not to make the data overwhelming with too many details Excel does not automatically update PivotTables 10

13 5. Change Values Field Change the Values Field Select the function used to calculate summary statistics Default is: o Sum for values o Count for text fields Specify a custom column heading Apply number formatting 11

14 5. Change Values Field Edit PivotTable Field by checking the following fields: Product ID Filters Distribution Rows Name Columns Quantity Values Overall Contribution Values Overall Cost Values 12

15 6. Sort, Filter, and Slice a PivotTable Sort data in a PivotTable Default is alphabetical by row label text To quickly rearrange data click in a cell in the column you want to sort, and then click Sort Smallest to Largest (Sort A to Z for text) or Sort Largest to Smallest (Sort Z to A for text) in the Sort & Filter group on the Options tab For specialized sorting click Sort in the Sort & Filter group on the Options tab If you click in a row label or column label first, you get a dialog box that has slightly different options than if you click on a value first 13

16 6. Sort, Filter, and Slice a PivotTable Apply filters to show a subset of data in a PivotTable Two types of filters: A report filter sets the overall conditions for aggregating data A group filter filters out data based on a row or column category Filter by one or multiple items, as well as by entering a search condition 14

17 6. Sort, Filter, and Slice a PivotTable Use slicers to filter data in a PivotTable Slicers: Are graphical Provide buttons that you can click for quick filtering Indicate the current filtering state To insert slicer click the Options tab, click the Insert Slicer button in the Sort & Filter group, click one or more field check boxes for which you want to create a slicer, and then click OK To use slicer o click a button to filter data 15

18 7. Format a PivotTable Basic formatting applied to PivotTables: Primary row labels formatted in bold Subtotals are bold Use PivotTable Tools Design tab to apply a PivotTable style and control: Font color Fill color Bolding Border lines 16

19 Get the Result Starting Table Product ID Distribution Name Materials Labor Others Overall Prices Quantity BR01-01, [retail] Pilsner $0.84 $ BR01-02, [retail] Bavarian Lager $0.84 $ BR01-03, [retail] Light Wheat $0.84 $ BR01-04, [retail] Red Wheat $0.84 $ BR01-05, [retail] Pale Ale $0.84 $ BR01-06, [retail] Bock Dark $0.84 $ BR01-07, [wholesale] Pilsner $0.84 $ BR01-08, [wholesale] Bavarian Lager $0.84 $ BR01-10, [retail] Nut Brown Ale $0.84 $ BR01-11, [retail] Special Offer $0.26 $0.84 $ Final Table 17