Hello Eddy,
I understand that you are expecting a linear plot as the outcome of your graphing. The reason you don’t get a linear plot is because you are plotting a single data point which gets plotted on the graph. The graph is indeed not blank but plots a single data point. You can view this by making the marker visible:
plot(x, y, 'o');
Which gives the plot:
To plot a straight line, you need a range of x values which you can use to get the y values from the slope and intercept data that you have.
Hope this helps.
