To create a polar plot:
- Define a range variable for the range
of values over which to plot the expression, for example
θ := -2·π, -4.8 .. 2·π
- Choose Graph > Polar Plot from the Insert menu, or type
[Ctrl] 7, to create a polar plot operator.
- Fill in the bottom middle placeholder with
the angular range variable.
- Fill in the left placeholder with a radial expression to plot, for example, cos(θ).
- Click away from the plot or press [Enter]. One point is plotted for each
value of the range variable and, unless you specify
otherwise, they are connected with straight lines.
Polar plots are created by mapping r and θ onto x and y
using the standard transformations:
x = r·cos(θ) and y = r·sin(θ),
where r and θ can assume
positive or negative values. This means that negative radii are treated as a phase shift in angle, rather than extending the radial scale.
Notes:
- You can graph any expression against any other expression, as long as they share the
same independent variables. You can also graph more
than one curve on a graph.
- Complex or imaginary points are not plotted. To plot the real or complex part of a
point, use the Re and Im functions.
- If a plot does not appear as smooth as you would like, try using a smaller step size
in the range variable.
- When plotting expressions, if you do not define a range for the dependent variable
on the angular-axis, Mathcad uses −10 to 10 as a default. This is
a QuickPlot.
- Vectors are graphed much as they are in X-Y
plots, using range-variable subscripts.
- You can modify the appearance and settings
for a plot by double-clicking on it. You can also resize
the graph.