Controlling Decimal Places in MATLAB

Introduction

• Default behavior of MATLAB when using %f as an insertion point is to display six decimal places.
• Decimal precision can be customized easily.

Customizing Decimal Precision

Specifying Decimal Places

• Syntax: Use %.nf where n is the number of decimal places desired.
  • Example: %.2f results in two decimal places.
• Usage: To display a value with specific precision:
  • Example: 7.00 is displayed as 7.00 by specifying %.2f.

Integer Display

• When integer display is preferable (e.g., whole number counts):
  • Example: 7 instead of 7.00 by using %.0f.

Numeric Formats: General (%g)

• %g Format: MATLAB chooses the best format automatically.
  • Displays integers as integers.
  • Uses scientific notation for very large/small numbers.

Working with Variables

• Example: Define mon_mass = 369.85;
• Usage in print statements:
  • Example: "The monster's mass is %.1f kilograms" results in "369.9", demonstrating rounding (not truncation).

Formatting Control

Minimum Number of Print Locations

• Syntax: %n.mf where n is the minimum number of print locations.
• Usage:
  • Example: %3.1f and %5.1f provide the same result if the number requires fewer places.
  • %9.1f ensures at least nine spaces are used.
• Purpose: Align numbers in a column for better readability across multiple lines.

Left Justification

• Syntax: %-n.mf uses a negative sign to left-justify.
  • Spaces appear to the right instead of the left.

Summary

• Understanding and controlling print format ensures values are displayed consistently.
• Useful for aligning data in tables or repeated outputs.

Next Steps

• Further exploration of fprintf functionality in subsequent presentations.