## Section 2.1 - Four operators

Starting from
now, I will explain all functions available in picFX, as well as some words
about their use in picture manipulation

Note that there are functions, like log or sinh, where the exact meaning of the
function has no importance, just the form of the curve is interesting.

There are others, like atan where you may either be interested in the form of
the curve (I have used it once for making a spread where the colour changes in
quite a narrow place) or in the actual 'use' of that function.

And remember that you can use Implicit function to know
what a function's curve looks like.

The four basic operators are

a+b; a-b; a*b; a/b: I guess you know what they do :-)

Use (x-a) instead of x in a function to move the graph a pixel to the __right__.
(x+a) Does the same to the __left__..

Use (x/a) instead of x to __enlarge__ the graph **a** times. (x*a) __reduces__
by **a** times

The same are of course valid for y. Remember that they act in the inverse of
what they seem to do. For example, For t fixed, x/2 gets t when x is 2t. For t
fixed, x-1 gets t when x is t+1...

I will speak about this a little again in the linear transformation part of
section 4.3: linear and non-linear transformations

Index

#### Chapter one:
Introduction

1.1:
Introduction

1.2: What can't
be done with picFX

1.3: Simple
spreads

#### Chapter two:
Mathematical function summary

2.1: Four
operators

2.2:
Trigonometric functions

2.3: Min, Max,
Modulo, Abs

2.4: Other
functions