DAY 7_TEAM I_PRISKILINA BASUMATARI

GRAPHS AND CHARTS

A bubble chart is a type of chart that displays three dimensions of data. Each entity with its triplet (v₁, v₂, v₃) of associated data is plotted as a disk that expresses two of the v_i values through the disk's xy location and the third through its size. Bubble charts can facilitate the understanding of social, economical, medical, and other scientific relationships.

Bubble charts can be considered a variation of the scatter plot, in which the data points are replaced with bubbles.

For bubble graph 3-4 variables are needed

Bubbles need to be finite in number they should b category or scale

The value of x and y axis need to be continuous

When to use a bubble chart

A bubble chart displays a set of numeric values as circles. It is especially useful for data sets with dozens to hundreds of values, or with values that differ by several orders of magnitude.

Step 1: Open Retail.sav file in SPSS

Step2: Use Analyze>Table>Custom Table option to create table.

Step3:  Row Variable: Store

             Column variable: Price, variety, Organization, Service, Item Quality and Overall Satisfaction

An output table is obtained as shown below

Step 4: Copy this table in Excel sheet and format

		Price satisfaction	Variety satisfaction	Organization  satisfaction	Service satisfaction
Store	Store 1	3.007	3.082	3.253	3.178
	Store 2	3.206	3.096	2.941	2.875
	Store 3	3.159	3.094	3.232	3.297
	Store 4	2.969	3.037	3.315	3.006

Step 5: Copy this table in notepad and prepare it for PERMAP as shown below:

Title: Store Satisfaction.

nobjects=4

nattributes=6

Attributelist

S1        3.007   3.082   3.253   3.178   3.171   2.986

S2        3.206   3.096   2.941   2.875   3.309   3.000

S3        3.159   3.094   3.232   3.297   3.080   3.312

S4        2.969   3.037   3.315   3.006   3.080   3.068

Step 6: Load this Notepad file in PERMAP and run to get a perceptual mapping of the 4 stores as shown below:

Analysis: Store 1 and Store4 are closer showing similar relationship with attributes. Store2 and 3 are quite different in attributes satisfaction level among customers.

Step7:  Use File>Save Solution As

Save the solution of PERMAP in text format

Step8: Use the data under (circled in above screenshot) in excel file again.

We can use this data to create Bubble Graph

Formatted data:

LOCATIONLIST
S1	-0.0282	-0.1066
S2	-0.4488	0.259
S3	0.333	0.2517
S4	0.1439	-0.4041

Use this data with any satisfaction parameter to analyze that parameter in detail.

For example, we are using it with Overall Satisfaction factor to study stores.

	Overall satisfaction
Store 1	2.986	-0.0282	-0.1066
Store 2	3.000	-0.4488	0.259
Store 3	3.312	0.333	0.2517
Store 4	3.068	0.1439	-0.4041

Example 2: Cell_inter.sav file

Step9: We can also create Radar chart to understand level of all attributes in all four stores on a scale as shown below:

 

The radar chart is a chart and plot that consists of a sequence of equi-angular spokes, called radii, with each spoke representing one of the variables. The data length of a spoke is proportional to the magnitude of the variable for the data point relative to the maximum magnitude of the variable across all data points. A line is drawn connecting the data values for each spoke. This gives the plot a star-like appearance and the origin of one of the popular names for this plot. Radar charts are a useful way to display observations with an arbitrary number of variables.