Row and column vectors in MATLAB - Step-by-Step Execution

Concept Flow - Row and column vectors

Start: Define vector

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Is vector horizontal?

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Row vector

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Use in math

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End

We start by defining a vector, then check if it is horizontal or vertical to classify it as a row or column vector, which affects how we use it in math.

Execution Sample

MATLAB

v_row = [1 2 3];
v_col = [1; 2; 3];
disp(v_row);
disp(v_col);

This code creates a row vector and a column vector, then displays both.

Execution Table

Step	Variable	Value	Action	Output
1	v_row	[1 2 3]	Create row vector
2	v_col	[1; 2; 3]	Create column vector
3	disp(v_row)		Display row vector	1 2 3
4	disp(v_col)		Display column vector	1 2 3
5			End of script

💡 All vectors created and displayed; script ends.

Variable Tracker

Variable	Start	After Step 1	After Step 2	Final
v_row	undefined	[1 2 3]	[1 2 3]	[1 2 3]
v_col	undefined	undefined	[1; 2; 3]	[1; 2; 3]

Key Moments - 2 Insights

Why does v_row use spaces and v_col use semicolons?

In MATLAB, spaces separate elements in a row vector (horizontal), while semicolons separate rows in a column vector (vertical), as shown in steps 1 and 2 of the execution_table.

Why does disp(v_col) show elements vertically?

Because v_col is a column vector, MATLAB displays each element on a new line, as seen in step 4 of the execution_table.

Visual Quiz - 3 Questions

Look at the execution_table at step 3, what is the output of disp(v_row)?

A 1 2 3

B [1; 2; 3]

C 1 2 3

D [1 2 3]

💡 Hint

Check the Output column in execution_table row with Step 3.

At which step is the column vector created?

A Step 2

B Step 1

C Step 3

D Step 4

💡 Hint

Look at the Action column in execution_table for vector creation.

If you replace semicolons with spaces in v_col, what changes in variable_tracker?

A v_row changes to a column vector

B v_col becomes a row vector with values [1 2 3]

C v_col remains a column vector

D No change in v_col

💡 Hint

Refer to how v_row and v_col are defined in variable_tracker and execution_table steps 1 and 2.

Concept Snapshot

Row vector: horizontal, elements separated by spaces, e.g. [1 2 3]
Column vector: vertical, elements separated by semicolons, e.g. [1; 2; 3]
Use disp() to display vectors
Row and column vectors differ in shape and display
Important for matrix operations and indexing

Full Transcript

This lesson shows how to create and display row and column vectors in MATLAB. A row vector is made by listing elements separated by spaces inside square brackets, like [1 2 3]. A column vector uses semicolons to separate elements vertically, like [1; 2; 3]. The code creates both vectors and uses disp() to show them. The row vector displays elements horizontally, while the column vector displays them vertically. Understanding this difference helps with matrix math and data organization in MATLAB.