---
language: sage
category: Extras / Interact
---
title: Introduction
descr: |
The decorator `@interact` is a powerful tool.
It allows you to add interactive UI elements to your worksheet,
such that a function is evaluate with different arguments.
Ref.: [@interact](http://doc.sagemath.org/html/en/reference/notebook/sagenb/notebook/interact.html#sagenb.notebook.interact.interact) --
but be aware, that this is **not** the same implementation as in Sage Worksheets.
The API is only similar, so expect some differences or missing details!
code: |
@interact
def func(k = slider(0, 10, .1)):
print("k: %s" % k)
s = (1 - sqrt(k))^2
print("s: %s" % s)
---
title: Symbolic Function
descr: |
This is a very simple example,
where the we first define a symbolic function $f(x)$,
and then substitute it with the variable `x` defined by the interact.
Both `x` variables aren't the same,
and therefore the evaluation of $f$ works as expected.
code: |
%var x
f(x) = 2*x + 1
@interact
def f_interact(x=(0, 100)):
print 'f({}) = {}'.format(x, f(x))
---
title: Multiple Sliders
descr: |
It's straight forward to add multiple sliders.
The `range_slider` retuns a tuple!
code: |
@interact
def func(k = slider(0, 10, .1), j = (-10, 10), l = range_slider(-5, 5)):
print("k: %s" % k)
print("j: %s" % j)
print("l: [%s, %s]" % l)
