plotting functions in matlab

Plotting Functions in MATLAB

MATLAB has build in function that allow one to generate x-y polar, contour and three-dimensional plots and bar charts. MATLAB also allow one to give title to graph, label the x and y axis, and a grid to graph. In addition, there are commands for controlling the screen and scaling.

X-Y Plot and annotations:

The Plot command generates a linear-y plot. This command has three variations.

Plot(x) 

Plot(x,y)

Plot (x1,y1,x2,y2,x3,y3,....Xn,Yn,)

If x is a vector, the command PLOT(x) is used.

if x and y are vector of the same length, then the command plot(x,y) is used.

Plot(x1,y1,x2,y2,x3,y3,.....Xn,Yn) is used for multiple arguments.

To write text on a graphic screen beginning at a point (x,y) on the graphic screen, one can use command text(x,y, 'any text')

Example:

t=0:0.25:7;

y =sin(t);

plot(t,y)

 

Example: Response of an RC Circuit:

Solution:

MATLAB Script

T=0:0.5:4;

Y=6*ept(-2*t);

Plot(t,y);

Title('Response of an RC Circuit:')

Xlabel(' Time in seconds')

Ylabel('Voltage in volts')

Grid 

Voltage and current of an RL Circuit:

For an RL Circuit, the voltage v(t) and current i(t) are given as:

V(t)=10cos(377t)

I(t)=5cos(377t+60o)

Solution: 

MATLAB Script