Converting between types in MATLAB - Step-by-Step Execution

Concept Flow - Converting between types

Start with a value

↓

Choose target type

↓

Apply conversion function

↓

Get new value in target type

↓

Use or display converted value

↓

End

Start with a value, pick the type you want, convert it using a function, then use the new value.

Execution Sample

MATLAB

x = 5.7;
y = int32(x);
disp(y);

Convert a decimal number 5.7 to an integer type and display it.

Execution Table

Step	Variable	Value Before	Action	Value After	Output
1	x	undefined	Assign 5.7	5.7
2	y	undefined	Convert x to int32	5
3	y	5	Display y	5	5

💡 All steps completed, conversion done and value displayed.

Variable Tracker

Variable	Start	After Step 1	After Step 2	Final
x	undefined	5.7	5.7	5.7
y	undefined	undefined	5	5

Key Moments - 2 Insights

Why does converting 5.7 to int32 give 5 and not 6?

Because int32 conversion in MATLAB truncates the decimal part, it does not round. See execution_table step 2 where 5.7 becomes 5.

What happens if you convert a string '123' to a number?

You can use a function like str2double to convert strings to numbers. Direct type casting like int32('123') does not convert the string to the number 123; instead, it converts the character codes. Use str2double for numeric conversion from strings.

Visual Quiz - 3 Questions

Look at the execution table, what is the value of y after step 2?

A 5.7

B 6

C 5

D undefined

💡 Hint

Check the 'Value After' column for y at step 2 in the execution_table.

At which step is the value 5.7 assigned to variable x?

A Step 3

B Step 1

C Step 2

D No step assigns 5.7

💡 Hint

Look at the 'Action' column for x in the execution_table.

If you convert x = 5.7 using double(x) instead of int32(x), what would y be?

A 5.7

B 5

C 6

D Error

💡 Hint

double(x) keeps the decimal part, unlike int32(x).

Concept Snapshot

Converting between types in MATLAB:
- Use functions like int32(), double(), char(), str2double()
- Numeric conversions may truncate decimals (int32)
- String to number: str2double()
- Converted value replaces original type
- Use disp() to show results

Full Transcript

This example shows how to convert a number from one type to another in MATLAB. We start with x assigned 5.7, a decimal number. Then we convert x to an integer type int32 and store it in y. The conversion truncates the decimal part, so y becomes 5. Finally, we display y which outputs 5. This process uses conversion functions like int32() to change types. Remember, converting decimals to integers cuts off the decimal part without rounding. Also, use special functions like str2double to convert strings to numbers. This helps when you want to change how MATLAB treats your data for calculations or display.