n = 5000;
p = 2;

X = rand(n,p);
w = round((rand(p,1)-.5)*30)

yhat = X*w;

figure(1);clf;
scatter(X(:,1),X(:,2),40,yhat(:),'filled');
colorbar
set(gca,'FontSize',20)
xlabel('feature 1')
ylabel('feature 2')


%%
n = 50;
x = linspace(-1,1,n)';
X = [x.^3 x.^2 x ones(n,1)];
p = 4;
w = rand(p,1)-.5;
yhat = X*w;
figure(2);
plot(x,yhat,'linewidth',3);
set(gca,'fontsize',20);
xlabel('x')
ylabel('yhat')