Bar and histogram plots in MATLAB - Step-by-Step Execution

Concept Flow - Bar and histogram plots

Prepare Data

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Choose Plot Type

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Bar Plot

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Call bar()

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Display Plot

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Analyze Visual Output

Start with data, pick bar or histogram plot, call the right function, then see the visual output.

Execution Sample

MATLAB

x = [5, 10, 15];
bar(x)

data = randn(1000,1);
histogram(data)

Create a bar plot for fixed values and a histogram for random data distribution.

Execution Table

Step	Action	Input Data	Function Called	Plot Type	Output Description
1	Prepare data for bar plot	[5, 10, 15]	None	None	Data array ready
2	Call bar()	[5, 10, 15]	bar(x)	Bar plot	Bars at heights 5, 10, 15 displayed
3	Prepare data for histogram	1000 random normal values	None	None	Random data generated
4	Call histogram()	random data	histogram(data)	Histogram plot	Histogram showing data distribution displayed
5	End of plotting	N/A	N/A	N/A	Plots shown on figure window

💡 All plotting commands executed, figures displayed.

Variable Tracker

Variable	Start	After Step 1	After Step 3	Final
x	undefined	[5, 10, 15]	[5, 10, 15]	[5, 10, 15]
data	undefined	undefined	1000 random values	1000 random values

Key Moments - 2 Insights

Why does bar(x) show bars at specific heights instead of a distribution?

Because bar() treats the input as heights of bars at positions 1, 2, 3, not as data to bin like histogram(). See execution_table step 2.

How does histogram(data) decide the number of bins?

Histogram uses default binning rules to group data into ranges. This is automatic unless specified. See execution_table step 4 where histogram() is called.

Visual Quiz - 3 Questions

Look at the execution table, what is the input data when bar() is called?

A [5, 10, 15]

B 1000 random values

C Empty array

D Single number 5

💡 Hint

Check execution_table row 2 under 'Input Data'

At which step does the histogram plot get displayed?

A Step 2

B Step 4

C Step 3

D Step 5

💡 Hint

Look at execution_table row 4 under 'Plot Type'

If you change x to [1,2,3,4], how does the bar plot output change?

A Bars at heights 1,2,3,4 displayed

B Histogram with 4 bins displayed

C No plot displayed

D Bars at heights 5,10,15 displayed

💡 Hint

Refer to variable_tracker for x values and execution_table step 2

Concept Snapshot

Bar and histogram plots in MATLAB:
- Use bar(x) to plot bars with heights from vector x.
- Use histogram(data) to plot data distribution.
- Bar plots show exact values; histograms group data into bins.
- Both display in figure windows automatically.
- Customize bins in histogram() if needed.

Full Transcript

This visual execution shows how to create bar and histogram plots in MATLAB. First, data is prepared: a vector x for bar plot and random data for histogram. Then bar(x) is called to display bars at heights 5, 10, and 15. Next, histogram(data) is called to show the distribution of 1000 random values. Variables x and data change as shown in the tracker. Key points include understanding bar plots show exact values as bars, while histograms group data into bins automatically. The quiz checks understanding of inputs and outputs at each step.