Problem with Linear Regression and Gradient Descent
Gradient descent probably didn't converge. I'd sugest scaling your feature on a [-1,1] or [0,1] scales, try increasing your learning rate and maybe add some code which checks the gradient's slope and if there is perhaps sequence of &lt;0,>0,&lt;0 it means that the learning rate is locally too large and cost function can't converge. In that case, learning rate should be decreased.