plot a straight line that is 40 long in matlab

You can use the plot function to draw a straight line in Matlab. Here is an example code snippet that draws a line 40 units long:

main.m
x = [0 1];
y = [0 0];
plot(x, y, 'k', 'LineWidth', 2)
54 chars
4 lines

The x array defines the starting and ending points of the line in the x direction. In this case, the line starts at x = 0 and ends at x = 1. The y array defines the starting and ending points of the line in the y direction. In this case, the line starts and ends at y = 0.

The 'k' in the plot command specifies that the line color should be black. The 'LineWidth' parameter specifies the width of the line in pixels.

You can adjust the x and y coordinates to draw lines of different lengths and orientations.