What does the >> n = 1:100; >> x = ( (-1).^(n+1) ) ./ (2*n - 1); >> y = sum(x) >>plot(x(1,1:4)) mean?

>> n = 1:100;

>> x = ( (-1).^(n+1) ) ./ (2*n - 1);

>> y = sum(x)

>>plot(x(1,1:4))

While executing this, what is the meaning and answer of plot line (Last command)?

[John D'Errico]

Why not try it?

Even better, why not take a basic MATLAB tutorial, and learn MATLAB? It will be time well spent. After all, is there a reason why we should be writing an entire tutorial in MATLAB for you here, when it already exists?

If not, then look at one line at a time. TRY IT! If you don't know what the first line does, then you definitely need to start reading the manual.

Answer 1

[Image Analyst]

x is a row vector so it doesn't need two indexes. y is assigned but not used. The plot() plots the first 4 values from the x array (row 1, columns 1-4):

n = 1:100;
x = ( (-1).^(n+1) ) ./ (2*n - 1)

x = 1×100

1.0000 -0.3333 0.2000 -0.1429 0.1111 -0.0909 0.0769 -0.0667 0.0588 -0.0526 0.0476 -0.0435 0.0400 -0.0370 0.0345 -0.0323 0.0303 -0.0286 0.0270 -0.0256 0.0244 -0.0233 0.0222 -0.0213 0.0204 -0.0196 0.0189 -0.0182 0.0175 -0.0169

y = sum(x)

y = 0.7829

plot(x(1, 1:4), 'b.-', 'LineWidth', 2, 'MarkerSize', 40)
grid on;
title('Plot of first 4 values of x in row 1')
ylabel('x');
xlabel('Index')

To learn other fundamental concepts, invest 2 hours of your time here:

MATLAB Academy - Free 2 hour training

[NN]

thank you .I was confused with plot function