% Matlab script der_script_template
% Finds numerical derivative of y = x.*2
% Steve Martel
% Date 8_26_04

% Set the increment dx
dx = 0.01;
% Set the domain of x (let x range from 0 to 10)
x = 0:dx:10;
% Determine how many values of x there are
n = ;
% Break the set of x-values into two sets,
% one that has all values but the last,
% the other that has all values but the first
x_beg = ;
x_end = ;
% Find the x-midpoints 
x_mid = ;
% Calculate y at the values of x, x_beg, and x_end
y = ;
y_beg = ;
y_end = ;        
% Find the slope using the values for y_beg, y_end, and dx 
slope = ;

% Plot figures

% Open up a figure window called "figure 1"
figure(1)
% Clear the figure
clf
% Plot the curve y = x.^2 on figure 1
plot(x,y)
% Keep the figure window to plot another curve
hold on
% Plot a red stairstep approximation of the curve
stairs(x,y,'r')
% Add title and labels to axes
title('y=x^2')
xlabel('x')
ylabel('y')

% Open up a figure window called "figure 2"
figure(2)
% Clear the figure
clf
% Plot the analytical solution for the slope
plot(x,2*x)
% Keep the figure window to plot another curve
hold on
% Plot the approximate slope of the curve y = x.^2 on figure 2
plot(x_end,junk,'r');
% Add title and labels to axes
title('Slope for the curve y=x^2 and numerical approximation (red)')
xlabel('x')
ylabel('y')