In 2D plots, the variable to use is x, in 3D plots, use x and y.
Multiplication is denoted by *, and division by /.
Exponents are denoted by**, and all multiplication must be
explicit. That is, 3x would generate and error, you would want
to use 3*x.
For example, the polynomial 3x^{4} + 4x - 2/3 would be
the following in Gnuplot:
Gnuplot also has a number of predefined functions. These are called by
putting the arguments in parenthesis, i.e., sin(x). These include the
following:
- The standard trig functions, sin, cos, and tan Note, to
use the constant pi can be referenced by just using pi.
- The inverse trig functions , asin, acos, and atan.
- The hyperbolic trig functions, sinh, cosh, and tanh.
- The exp and log function. exp raises e to the power of its
argument. For example, 4e^{2x} would be
4*exp(2*x) in Gnuplot. log returns the natural log (base
e) of it's argument. This corresponds to ln in normal
math notation.
- For information on other functions, type help functions
in Gnuplot.
The following are other examples of functions. Make sure you
understand what functions are being described.
- (x**2 - 4)/(x +2)
- x**2 + y**2 - (x*y)**(2/3)
- log(exp(x)) (Hint, this simplifies to x)
- sin(x*y)
- 3*x**2 + 6/(1*y**2)
Table of Contents - Previous - Starting and Quitting GnuPlot - Next - A Simple Example
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Last Modified: 10/29/96