This page describes how to plot y = f(x) by connecting the data points with a line.

Two-dimensional line and symbol plots are created with the
`plot` command. In its simplest form `plot` takes
two arguments
>> plot(xdata,ydata)

where `xdata` and `ydata` are vectors containing
the data. Note that `xdata` and `ydata` must be
the same length and both must be the same type, i.e., both must
be either row or column vectors. Additional arguments to the
plot command provide other options including the ability to plot
multiple data sets, and a choice of colors, symbols and line
types for the data.

Here are the MATLAB commands to create a simple plot of y =
sin(3*pi*x) from 0 to 2*pi. For your convenience these commands
are also stored in the sin3xPlot.m
script file. (Refer to
``help with downloading scripts''
for instructions on downloading this script to your computer.)
>> x = 0:pi/30:2*pi; % x vector, 0 <= x <= 2*pi, increments of pi/30
>> y = sin(3*x); % vector of y values
>> plot(x,y) % create the plot
>> xlabel('x (radians)'); % label the x-axis
>> ylabel('sine function'); % label the y-axis
>> title('sin(3*x)'); % put a title on the plot

The effect of the labeling commands, `xlabel`, `ylabel`,
and `title` are indicated by the text and red arrows in the
figure. **Don't skimp on the labels!**

Log-log and semi-log plots are created with commands that
act just like the `plot` command. These are summarized in
the table below

Command Name |
Plot type |

`loglog` |
log(y) versus log(x) |

`semilogx` |
y versus log(x) |

`semilogy` |
log(y) versus x |

**Commands for creating log-log and semilog plots**

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