Visualization

Question 1

Categorical Variables

Answer 1

Categorical Variables are variables that cannot be classified as a numerical value
Categorical variables can be classified as either nominal or ordinal
Nominal
- No logical order
- Examples include eye color, dog breed, nationality, etc.
Ordinal
- Has an inherit order
- Examples include shirt size, education level, letter grade, etc

Question 2

Numerical Variables

Answer 2

Continuous
- Can take on any value within a range
- Includes decimal or fractional values
Discrete
- Only defined for whole numbers
- Does not make sense for fractional values

Question 3

Making a Bar chart in plotly

Answer 3

fig = px.bar( data, x=”Language”, y=”Users”, orientation=”v”, height=350, width=450)

You can make a horizontal Bar chart by making orientation=”h”

Question 4

Making a pie chart in plotly

Answer 4

fig = px.pie(data, names=”Race/Ethnicity”, values=”Population Percentage”, height=400, width=500)

Question 5

Common Categorical Graph Types

Answer 5

Vertical Bar Charts
Horizontal Bar Charts
Pie Charts

Question 6

Common Numerical Bar Charts

Answer 6

Line Graphs
Scatterplots
Histograms
Boxplots

Question 7

Making a scatterplot in plotly

Answer 7

fig = px.scatter(data, “Height”, “Weight”)

Question 8

Line Graph

Answer 8

Line graphs are similar to scatterplots, but have some key differences
While scatterplots often have multiple y-values for each x-value, line graphs have exactly one
Line graphs are most often used when the x-axis is a time period with a constant interval
While scatterplots often have multiple y-values for each x-value, line graphs have exactly one
Most importantly, line graphs represent trend.

Question 9

Histogram

Answer 9

Bar : distributions of quantitative variables
Bar width: Can be uneven
Bar order: contiguous
Frequency: By area of bars

Given a list of numerical values, a histogram displays the distribution of these values by grouping them in bins and showing the frequency of values within each bin.

Question 10

Relative Frequency Histogram

Answer 10

Display the bins along the x-axis, and the percentage of data (relative frequency) that is contained within that bin on the y-axis
Formulae for computing height and area of a relative frequency histogram bar:
Height = % of data per x axis unit
Area = % of data in the bin
Total area = 100%

Question 11

Binning

Answer 11

Binning is the process of grouping data into “bins” of a given size.