For an exercise at school, I'm trying to plot a function where the variable is a matrix. The function is very simple: y=x^4 The matrix, x, is 0:0.01:20 so it has a range from 0 to 20, and there are 2000 between them. My problem is, the scale of the x-axis is 0-2000, and not 0-20 as i'd suppose it to be. According to the current graph: 1000^4=10000, while it should be: 10^4=10000. What am I doing wrong?