Disconnected Lines

Disconnected Lines

Source: disconnected_lines.f90

This example demonstrates how to create plots with disconnected line segments by using NaN (Not-a-Number) values as separators.

  • Disconnected line segments: Use NaN values to break lines into separate segments
  • Mixed plot types: Combine continuous lines with individual markers
  • Multiple line styles: Different markers and line styles in the same plot
  • Multi-format output: Generate PNG, PDF, and ASCII versions

The example generates three output files: - output/example/fortran/disconnected_lines/disconnected_lines.png - output/example/fortran/disconnected_lines/disconnected_lines.pdf - output/example/fortran/disconnected_lines/disconnected_lines.txt

The plot shows: 1. First segment: Sine wave from 0 to π (connected with lines and circles) 2. NaN separator: Creates a break in the line 3. Second segment: Cosine wave from π to 2π (connected separately) 4. NaN separator: Another break 5. Third segment: Single horizontal point at y=0.5 6. Independent point: Red square marker at (8, -0.5)

use, intrinsic :: ieee_arithmetic, only: ieee_value, ieee_quiet_nan real(8) :: nan nan = ieee_value(nan, ieee_quiet_nan)

! Add NaN to break the line x(5) = nan y(5) = nan

  • Plot multiple data series that shouldn't be connected
  • Create gaps in time series data
  • Highlight missing or invalid data points

  • Separate logical segments within the same dataset

  • NaN values are ignored during line drawing but preserved in data

  • Both X and Y coordinates should be set to NaN for clean breaks
  • Markers are still drawn at valid data points before/after NaN
  • Legend entries apply to entire data series including disconnected segments

Files

  • disconnected_lines.f90 - Source code
  • Generated media in output/example/fortran/disconnected_lines/

Running

make example ARGS="disconnected_lines"

Output

Disconnected Lines

disconnected_lines.png

ASCII output:

(Content embedded here)

Download ASCII

Download PDF