plotData

Signed-off-by: Yi Zou <yi.zou.linux@gmail.com>
sigmoid

Signed-off-by: Yi Zou <yi.zou.linux@gmail.com>
cost func and gradient for log reg

Signed-off-by: Yi Zou <yi.zou.linux@gmail.com>
prediction fminunc

Signed-off-by: Yi Zou <yi.zou.linux@gmail.com>
ex2: regulaization

Signed-off-by: Yi Zou <yi.zou.linux@gmail.com>
ex3: original

Signed-off-by: Yi Zou <yi.zou.linux@gmail.com>
ex3: lrCostFunction

Signed-off-by: Yi Zou <yi.zou.linux@gmail.com>
ex3: One-vs-all classification

Signed-off-by: Yi Zou <yi.zou.linux@gmail.com>