Why my code produce an incorrect graph in MATLAB?

Question

Does anyone know why my MATLAB code is give an incorrect graph?

I want to plot f(x)=exp(-x)-2*x.

The codes as follows.

clear all;
clc;
h=0.01;
x=-1:h:1;
f=exp(-x)-2*x;
plot(f,x,'color','r');
grid on;
xlabel('x');
ylabel('y');

This code give me a figure like this.

We know f(0)=1. But in the graph f(0) not equal to 1. Does anyone know why my code produce an incorrect graph?

Answer 1

The axis on your graph are inverted. The line that says

plot(f,x,'color','r');

should be:

plot(x,f,'color','r');

The plot function expects first the abscissa (x) and then the ordinate (f).