Dirk Krause


LaTeX::PGF::Diagram2D::Axis - Perl extension for drawing 2D diagrams (axis).


  use LaTeX::PGF::Diagram2D;
  my $Uq = 1.0;
  my $Ri = 4.0;
  sub I($)
    my $RL = shift;
    my $back = $Uq / ($Ri + $RL);
    return $back;
  # 10 centimeters wide, 6 centimeters high 
  my $d = LaTeX::PGF::Diagram2D->new(10.0, 6.0);
  # R (on the x axis) is in the range 0 ... 10
  $d->axis('b')->set_linear(0.0, 10.0)->set_grid_step(1.0)
  # I (on the y axis) is in the range 0 ... 0,3
  $d->axis('l')->set_linear(0.0,  0.3)->set_grid_step(0.05)
  my $p = $d->plot('b', 'l');


Each object of this class represents one axis of the diagram, either bottom, left, right or top axis. The object methods can be used to configure the axis:

Axis values

set_linear(min, max)

sets a linear scale and assigns the specified minimum and maximum to the axis.

set_logarithmic(min, max)

uses a logarithmic scale. Both minimum and maximum must be positive.

Grid and tics


chooses the step size for the grid. Negative values are used to disable the grid. A grid is only drawn for ``bottom'' and ``left'' axis. For linear axes the step is added to the minimum, and again... to find the values for grid positions. For logarithmic axes the step is used as a factor.


chooses the step size for showing scale values.

Labels and units


sets the axis label. Normally you should write this in LaTeX's math mode.


sets the text for the unit. Normally this is written upright.


decides whether or not to omit some scale values to free space to print the unit.

Note: You must not omit scale value 0.


sets the color for axis label and arrow. Choose a LaTeX color specification like ``blue'' or ``blue!50!black''.

Distances and borders

set_tic_offset(offset) setes the offset in cm between the canvas border and the right anchor of the scale value texts. For ``top'' and ``bottom'' axis this is the distance to the lower or upper text border.

If you use the right y axis you will have to correct this offset in most cases.


sets the offset between the canvas border and the center of the axis label.


sets the offset between canvas border and image border.


None by default.



Dirk Krause, <krause@localdomain>


Copyright (C) 2011 by Dirk Krause

This library is free software; you can redistribute it and/or modify it under the same terms as Perl itself, either Perl version 5.12.3 or, at your option, any later version of Perl 5 you may have available.