4. Plotting Data - Arduinerd/PDS-MatLab GitHub Wiki
Native MatLab Plots
In order to plot with just built-in MatLab functionality, it is necessary to declare arrays with the domain and range.
Declare an array with n elements between start and end inclusively:
x=linspace(start,end,n)
It is possible to plot just the range but the view will not fit exactly
Plotting in 3D requires a 2x2 array to be declared:
[x y] = meshgrid(xDomain, yDomain)
After defining the range of z, you can plot by the surf(z) command
Plots from Toolboxes
Within the Symbolic Toolbox there are a set of functions which make plotting much easier than via the native MatLab way.
Plotting y=x:
>>ezplot('y=x')
The default range of ezplot is set to -2pi to 2pi
or
>>syms x
>>fplot(x)
The default range of fplot is set to -5 to 5
Plotting x^2+y^2 = 9:
>>ezplot('x^2+y^2 = 9')
or
>>syms x y
>>fimplicit(x^2+y^2==9)
Plotting Parametric Functions:
>>syms t
>>x = t*sin(5*t);
>>y = t*cos(5*t);
>>ezplot(x, y) or fplot(x,y)
- By adding a second argument to any of these functions, you can specify the domain in an array
- You can additionally declare a symbolic function through
syms f(x, y)orsyms f(x) - Setting a symbolic function to a given equation (without quotes) will allow you to use the function afterwards
Customizing Plots
Adding features requires you to set a plot equal to a variable or to edit the figure as a whole.
Start by creating a figure with >>figure and entering in >>hold on. This will cause the graphs to not reset upon adding a new function.
When adding a function to
fplot()each will have a different color. However, eachezplot()will be the same unless you change the color manually.
Set X Label
>>xlabel("labelX")
Set Y Label
>>ylabel("labelY")
Set Line Color
>>plot(x,y,'color','red')
or
>>ez = ezplot('y=x')
>>set(ez,'color','red')
Create Legend
>>legend("line1","line2", ...)
Set Title
>>title("title")
If you want to create these from a script, you can see the code by selecting "Generate Code" in the File menu of the figure window
