MATLAB Data Analysis and Trigonometric Plotting

MATLAB Statistical Analysis of Student Weights

Analyze the weight of 30 students to find the minimum, maximum, average, standard deviation, and plot a histogram.

>> a=[ 71 82 65 75 77 91 59 84 89 81 73 91 82 75 96 85 69 76 81 92 84 79 77 95 81 79 84 85 76 82]

a = Columns 1 through 12
    71 82 65 75 77 91 59 84 89 81 73 91

Columns 13 through 24
    82 75 96 85 69 76 81 92 84 79 77 95

Columns 25 through 30
    81 79 84 85 76 82

>> max(a)
ans = 96

>> min(a)
ans = 59

>> mean(a)
ans = 80.5333

>> std(a)
ans = 8.4516

>> hist(a)

Plotting Trigonometric Functions in MATLAB

Follow these steps to plot trigonometric functions:

• Plot the value of the cosine within [0, 2π] with a step of π/20.
• Label the axes and add a title.
• Add the sine function to that graph using the hold command.
• Place legends to distinguish both graphics.

>> x=0:pi/20:2*pi

x = Columns 1 through 9
    0 0.1571 0.3142 0.4712 0.6283 0.7854 0.9425 1.0996 1.2566

Columns 10 through 18
    1.4137 1.5708 1.7279 1.8850 2.0420 2.1991 2.3562 2.5133 2.6704

Columns 19 through 27
    2.8274 2.9845 3.1416 3.2987 3.4558 3.6128 3.7699 3.9270 4.0841

Columns 28 through 36
    4.2412 4.3982 4.5553 4.7124 4.8695 5.0265 5.1836 5.3407 5.4978

Columns 37 through 41
    5.6549 5.8119 5.9690 6.1261 6.2832

>> y=cos(x)

y = Columns 1 through 9
    1.0000 0.9877 0.9511 0.8910 0.8090 0.7071 0.5878 0.4540 0.3090

Columns 10 through 18
    0.1564 0.0000 -0.1564 -0.3090 -0.4540 -0.5878 -0.7071 -0.8090 -0.8910

Columns 19 through 27
    -0.9511 -0.9877 -1.0000 -0.9877 -0.9511 -0.8910 -0.8090 -0.7071 -0.5878

Columns 28 through 36
    -0.4540 -0.3090 -0.1564 -0.0000 0.1564 0.3090 0.4540 0.5878 0.7071

Columns 37 through 41
    0.8090 0.8910 0.9511 0.9877 1.0000

>> plot(x,y)
>> xlabel('x')
>> ylabel('cos(x)')
>> ylabel('cos(x)')
>> plot(x,y)
>> title('cosine of x')
>> xlabel('x')
>> ylabel('cos(x)')
>> hold
Current plot held

>> z=sin(x)

z = Columns 1 through 9
    0 0.1564 0.3090 0.4540 0.5878 0.7071 0.8090 0.8910 0.9511

Columns 10 through 18
    0.9877 1.0000 0.9877 0.9511 0.8910 0.8090 0.7071 0.5878 0.4540

Columns 19 through 27
    0.3090 0.1564 0.0000 -0.1564 -0.3090 -0.4540 -0.5878 -0.7071 -0.8090

Columns 28 through 36
    -0.8910 -0.9511 -0.9877 -1.0000 -0.9877 -0.9511 -0.8910 -0.8090 -0.7071

Columns 37 through 41
    -0.5878 -0.4540 -0.3090 -0.1564 -0.0000

>> plot(x,z)
>> legend('cos(x)','sin(x)')
>> ylabel('y')