# Pyxplot

## Examples - Cornu spiral

A parametric plot which uses Pyxplot's numerical integration function to draw a Cornu spiral

This is an example of a parametric plot. Rather than plotting some function f(x) against the vertical axis, as a function of x, two expressions are given for x(t) and y(t) as a function of some variable t, which is varied over the range specified in the set trange command.

In addition we use Pyxplot's built-in functions for numerical integration to evaluate a curve known as the Cornu spiral. A legend is displayed beneath the plot, and Pyxplot automatically generates neat algebraic representation of the expressions plotted, in this case converting evaluations of its numerical integration functions into integral signs.

### Script

set xlabel "$x$"
set ylabel "$y$"
set xrange [-pi*0.4:pi*0.4]
set yrange [-pi*0.4:pi*0.4]
set xformat r"%s$\pi$"%(x/pi)
set yformat r"%s$\pi$"%(y/pi)
set xtics 0.2*pi ; set mxtics 0.05*pi
set ytics 0.2*pi ; set mytics 0.05*pi
set trange [-5:5]
set samples 1000
set key below
set size square
set grid
set title 'The Cornu Spiral'
plot parametric (int_dq(sin(q**2),0,t)):(int_dq(cos(q**2),0,t))