Dirk Krause
and 1 contributors

# NAME

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

# SYNOPSIS

``````  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);

\$d->set_font_size(12.0);

# 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)
->set_tic_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)
->set_tic_step(0.1);

my \$p = \$d->plot('b', 'l');
\$p->set_xy_fct(\&I);

\$d->write("test001a.pgf");``````

# DESCRIPTION

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

set_grid(step)

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.

set_tic_step(step)

chooses the step size for showing scale values.

## Labels and units

set_label(text)

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

set_unit(text)

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

set_omit(number)

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

Note: You must not omit scale value 0.

set_color(color)

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.

set_label_offset(offset)

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

set_border(offset)

sets the offset between canvas border and image border.

None by default.