change sparse example from regression to classification (apache#165)

example/sparse/linear_regression.py → example/sparse/linear_classification.py

@@ -22,22 +22,22 @@
 import argparse
 import os
 
-parser = argparse.ArgumentParser(description="Run sparse linear regression " \
+parser = argparse.ArgumentParser(description="Run sparse linear classification " \
                                              "with distributed kvstore",
                                  formatter_class=argparse.ArgumentDefaultsHelpFormatter)
 parser.add_argument('--profiler', type=int, default=0,
                     help='whether to use profiler')
 parser.add_argument('--num-epoch', type=int, default=1,
                     help='number of epochs to train')
-parser.add_argument('--batch-size', type=int, default=512,
+parser.add_argument('--batch-size', type=int, default=8192,
                     help='number of examples per batch')
 parser.add_argument('--num-batch', type=int, default=99999999,
                     help='number of batches per epoch')
 parser.add_argument('--dummy-iter', type=int, default=0,
                     help='whether to use dummy iterator to exclude io cost')
 parser.add_argument('--kvstore', type=str, default='dist_sync',
                     help='what kvstore to use [local, dist_sync, etc]')
-parser.add_argument('--log-level', type=str, default='debug',
+parser.add_argument('--log-level', type=str, default='DEBUG',
                     help='logging level [debug, info, error]')
 parser.add_argument('--dataset', type=str, default='avazu',
                     help='what test dataset to use')
@@ -78,18 +78,18 @@ def next(self):
 
 datasets = { 'kdda' : kdda, 'avazu' : avazu }
 
-def regression_model(feature_dim):
-     initializer = mx.initializer.Normal()
+def linear_model(feature_dim):
      x = mx.symbol.Variable("data", stype='csr')
      norm_init = mx.initializer.Normal(sigma=0.01)
-     v = mx.symbol.Variable("v", shape=(feature_dim, 1), init=norm_init, stype='row_sparse')
-     embed = mx.symbol.dot(x, v)
+     weight = mx.symbol.Variable("weight", shape=(feature_dim, 1), init=norm_init, stype='row_sparse')
+     bias = mx.symbol.Variable("bias", shape=(1,), init=norm_init)
+     dot = mx.symbol.dot(x, weight)
+     pred = mx.symbol.broadcast_add(dot, bias)
      y = mx.symbol.Variable("softmax_label")
-     model = mx.symbol.LinearRegressionOutput(data=embed, label=y, name="out")
+     model = mx.symbol.SoftmaxOutput(data=pred, label=y, name="out")
      return model
 
 if __name__ == '__main__':
-
     # arg parser
     args = parser.parse_args()
     num_epoch = args.num_epoch
@@ -138,7 +138,7 @@ def regression_model(feature_dim):
         train_data = DummyIter(train_data)
 
     # model
-    model = regression_model(feature_dim)
+    model = linear_model(feature_dim)
 
     # module
     mod = mx.mod.Module(symbol=model, data_names=['data'], label_names=['softmax_label'])
@@ -148,11 +148,10 @@ def regression_model(feature_dim):
                            learning_rate=0.1, rescale_grad=1.0/batch_size/num_worker)
     mod.init_optimizer(optimizer=sgd, kvstore=kv)
     # use accuracy as the metric
-    metric = mx.metric.create('MSE')
+    metric = mx.metric.create('Accuracy')
 
     # start profiler
     if profiler:
-        import random
         name = 'profile_output_' + str(num_worker) + '.json'
         mx.profiler.profiler_set_config(mode='all', filename=name)
         mx.profiler.profiler_set_state('run')
@@ -162,31 +161,22 @@ def regression_model(feature_dim):
     data_iter = iter(train_data)
     for epoch in range(num_epoch):
         nbatch = 0
-        end_of_batch = False
         data_iter.reset()
         metric.reset()
-        next_batch = next(data_iter)
-        while not end_of_batch:
+        for batch in data_iter:
             nbatch += 1
-            batch = next_batch
-            # TODO(haibin) remove extra copy after Jun's change
-            row_ids = batch.data[0].indices.copyto(mx.cpu())
+            row_ids = batch.data[0].indices
             # pull sparse weight
-            index = mod._exec_group.param_names.index('v')
-            kv.row_sparse_pull('v', mod._exec_group.param_arrays[index],
+            index = mod._exec_group.param_names.index('weight')
+            kv.row_sparse_pull('weight', mod._exec_group.param_arrays[index],
                                priority=-index, row_ids=[row_ids])
             mod.forward_backward(batch)
             # update parameters
             mod.update()
-            try:
-                # pre fetch next batch
-                next_batch = next(data_iter)
-                if nbatch == num_batch:
-                    raise StopIteration
-            except StopIteration:
-                end_of_batch = True
             # accumulate prediction accuracy
             mod.update_metric(metric, batch.label)
+            if nbatch == num_batch:
+                break
         logging.info('epoch %d, %s' % (epoch, metric.get()))
     if profiler:
         mx.profiler.profiler_set_state('stop')