 put forth in the paper.
"triangular":
A basic triangular cycle w/ no amplitude scaling.
"triangular2":
A basic triangular cycle that scales initial amplitude by half each cycle.
"exp_range":
A cycle that scales initial amplitude by gamma**(cycle iterations) at each
cycle iteration.
For more detail, please see paper.</p>
<h1 id="example">Example</h1>
<pre><code>```python
    clr = CyclicLR(base_lr=0.001, max_lr=0.006,
                        step_size=2000., mode='triangular')
    model.fit(X_train, Y_train