There will also be a toolbar at the top of the window which provides basic functions, and a status bar at the bottom which displays information.
You can right click on the Plotter window for a menu.
From left to right, the toolbar buttons are:
A Function Editor contains four items. From left to right these are:
To plot a function, type it into the Function Edit Box and then press enter
.
Plotter will then draw this function on the graph. For example type 2*x + 3
to draw a graph of the function y = 2x + 3
. Note that the times sign *
is required (see Syntax for Functions).
Plotter can draw graphs containing more than one function. To find out how, see Adding and Removing Functions.
Operator  What it does 

+ 
Addition 
 
Subtraction 
* 
Muliplication 
/ 
Division 
** 
Power 
When you type in a function, Plotter checks it for mistakes. If it finds any problems, it displays a message showing the error information. This should enable you to correct the error and continue. The two most common types of errors are SyntaxErrors (caused by problems with syntax, often brackets, commas etc) and NameErrors (caused by tyring to call a function or use a variable that doesn't exist). As mentioned above, in contrary to normal algebra you must always use multiplication signs when entering functions.
By default, functions are evaluated in a namespace into which the Python math
module has been imported. This means that the standard mathematical functions are available,
as well as the constants pi
and e
. The following mathematical
functions are available (reproduced from the Python documentation):
Function  Description 

acos (x)  Return the arc cosine of x. 
asin (x)  Return the arc sine of x. 
atan (x)  Return the arc tangent of x. 
atan2 (y, x)  Return atan(y / x). 
ceil (x)  Return the ceiling of x as a real. 
cos (x)  Return the cosine of x. 
cosh (x)  Return the hyperbolic cosine of x. 
exp (x)  Return e**x. 
fabs (x)  Return the absolute value of the real x. 
floor (x)  Return the floor of x as a real. 
fmod (x, y)  Return x % y. 
frexp (x)  Return the matissa and exponent for x. The mantissa is positive. 
hypot (x, y)  Return the Euclidean distance, sqrt(x*x + y*y). 
ldexp (x, i)  Return x * (2**i). 
log (x)  Return the natural logarithm of x. 
log10 (x)  Return the base10 logarithm of x. 
pow (x, y)  Return x**y. 
sin (x)  Return the sine of x. 
sinh (x)  Return the hyperbolic sine of x. 
sqrt (x)  Return the square root of x. 
tan (x)  Return the tangent of x. 
tanh (x)  Return the hyperbolic tangent of x. 
Plotter can easily be extended to add new functions if required (see Extending Plotter). For more information about the specifics of Python syntax, you should consult the Python documentation, which is available from the Python web site.
This table shows the three function types that Plotter supports:
Menu Option  Function Type  Comment 

y = 
Enter an expression in terms of x. y is calculated
for many values of x, and the points (x,y) are plotted.y = f(x) 

x, y = 
Enter two expressions in terms of t seperated by a comma.
x and y are calculated for many values of t
and the points (x,y) are plotted.x, y = f(t), g(t) 

r = 
Enter an expression in terms of t. r is calculated for many
values of t, and then the cartesian coordinates of those points are calculated
and plotted.
Only positive values of r are plotted.r = f(t) 
The default function type for new functions is Cartesian (y =
).
examples.plot
file in the Plotter examples
directory.
Algebraic Function  Function Type  Plotter Function  Comment 

y = 2x + 3  Cartesian (y =)  2*x + 3 
Straight line 
y = x^2  Cartesian (y =)  x**2 
Parabola 
y = sin x  Cartesian (y =)  sin(x) 
Sine wave where x is in radians 
r = t  Polar (r =)  t 
Spiral 
r = 5sin 5t  Polar (r =)  5*sin(5*t) 
Flower shape with five petals 
x = 4t, y = 4/t  Parametric (x, y =)  4*t, t/4 
Rectangular hyperbola 
x = 5cos t, y = 3 sin t  Parametric (x, y =)  5*cos(t), 3*sin(t) 
Ellipse with major radius 5 and minor radius 3 
You can change the range of colours available for graphing on the Colour tab in the Options dialog box.
To pan the graph, hold down the pan mouse button (by default the left mouse button), and drag the mouse. The new position of the axes is shown as you drag. When you release the mouse button, the graph is redrawn in the new position.
There are two different ways of zooming in Plotter. The first is used when you want to zoom in on a region. The second method is used for zooming in and out by a fixed amount; for information about this see Zooming In and Out.
To zoom to a region, place the mouse at one corner of the region, and hold down the zoom mouse button (by default this is the middle button). Drag the mouse towards the other corner of the region on which you wish to zoom in. You will notice that the zoom region is shown on the status bar. When you release the mouse button, the graph is zoomed and redrawn.