Any questions that apply to plotting in Maple will appear here.
Click on links below to obtain tips, tricks and FAQ about plotting for probability and statistics.
Here is a sheet that shows how to use surface to plot density functions.
It shows also how to use such plot for "Value at Risk" figures.
See Value at Risk definition at Wikipedia.
View 744_plot-fill.mw on MapleNet or Download 744_plot-fill.mw
View file details
A1: You forgot to specify a range on the independent variable.
> f:=2-x; > plot(f); WRONG Plotting error, empty plot > plot(f,x=-1..1); RIGHT
A2: You might be plotting a quantity that isn't defined.
For example, you might have defined Y but then asked Maple
to plot y. Maple is case-sensitive, and many strange
behaviors are the result of typing a variable name in the
wrong case.
Another way a plotted quantity can be undefined is if you
didn't use the assignment operator := to define it.
> y=sin(x); WRONG > plot(y,x=-1..1); Plotting error, empty plot
A3: There might be a scaling problem, as in this example.
> plot(exp(x^2),x=0..10);
Here the numbers get so big that all of the points Maple
calculates before the last one are negligible compared to the
last point in the plot, so they are all lost in the x-axis
and no curve appears.
A4: The quantity you are trying to plot might contain variables
other than the independent variable in the plot.
> g:=x^2-3*a;
2
g := x - 3 a
> plot(g,x=-1..1);
Plotting error, empty plot.
Here both a and x are variables in the definition of g. In order
to plot a function Maple needs to compute numerical values for it
at different values of x, and that's impossible until all of the
other quantities in the function have been given numerical values.
In this example, assigning a value to "a" fixes the problem.
> a:=1; > plot(g,x=-1..1); Now this command works.