Update.
[mygptrnn.git] / mygpt.py
index 7c9991f..040845e 100755 (executable)
--- a/mygpt.py
+++ b/mygpt.py
@@ -126,7 +126,6 @@ class AddPositionalEncoding(nn.Module):
 
 import pscan
 
-
 # X is /.../xTxD   A is /.../xT   Y_init is /.../xD
 
 
@@ -147,6 +146,18 @@ def pscan_dim(A, X, Y_init, dim=-2):
     return Y
 
 
+def pscan_rgrad(grad_Y, A, X, Y_init, dim=-2, eps=1e-2):
+    with torch.no_grad():
+        s_A, s_X = 0, 0
+        for t in range(X.size(dim) - 1, 0, -1):
+            delta = (grad_Y[t] - s_A) / A[t].grad
+            s_A += A[t].grad * delta
+            A[t].grad = delta
+            delta = (grad_Y[t] - s_X) / X[t].grad
+            s_X += X[t].grad * delta
+            X[t].grad = delta
+
+
 def pscan_shape(A, X, Y_init):
     s = X.size()
     A = A.reshape(-1, s[-2])
@@ -191,7 +202,7 @@ class DumbRec(nn.Module):
         attention_dropout=0.0,
         len_max=1e5,
         logger=print,
-        **kwargs,
+        args=None,
     ):
         super().__init__()
 
@@ -322,7 +333,7 @@ class KVRec(nn.Module):
         attention_dropout=0.0,
         len_max=1e5,
         logger=print,
-        **kwargs,
+        args=None,
     ):
         super().__init__()
 
@@ -476,34 +487,30 @@ class Caterpillar(nn.Module):
         attention_dropout=0.0,
         len_max=1e5,
         logger=print,
-        **kwargs,
+        args=None,
     ):
         super().__init__()
 
         warnings.warn("Caterpillar", RuntimeWarning)
 
-        def randw(*d, amplitude=None):
-            if amplitude is None:
-                amplitude = 1 / math.sqrt(d[-1])
-            return nn.Parameter(amplitude * torch.randn(*d))
+        def randw(*d, factor=1):
+            return nn.Parameter(torch.randn(*d) * factor / math.sqrt(d[-1]))
 
         self.caterpillar_length = caterpillar_length
         self.caterpillar_height = caterpillar_height
         self.attention_dropout = attention_dropout
 
-        self.proba_gate_dropout = 0.0
+        self.gate_dropout_proba = args.gate_dropout_proba
+        self.gate_dropout_sync = args.gate_dropout_sync
+        self.gate_dropout_replace = args.gate_dropout_replace
 
-        default_b_G = kwargs.get("default_b_G")
-        if default_b_G is None:
-            default_b_G = -math.log(caterpillar_height - 1)
-
-        logger(f"default_b_G {default_b_G}")
+        ######################################################################
 
-        self.w_G = randw(nb_heads, caterpillar_height, dim_model)
-        self.b_G = nn.Parameter(torch.full((nb_heads, caterpillar_height), default_b_G))
+        self.w_G = randw(nb_heads, caterpillar_height, dim_model, factor=1.0)
+        self.b_G = nn.Parameter(torch.full((nb_heads, caterpillar_height), 0.0))
 
         self.w_K = randw(nb_heads, dim_qk, dim_model)
-        self.w_V = randw(nb_heads, dim_v, dim_model)
+        self.w_V = randw(nb_heads, dim_v, dim_model, factor=1)
         self.w_Q = randw(nb_heads, dim_qk, dim_model)
         self.w_O = randw(dim_v * nb_heads, dim_model)
 
@@ -518,14 +525,14 @@ class Caterpillar(nn.Module):
             dim_v,
         )
 
-    def reset_inner_loss(self):
-        self.acc_attention = 0
-        self.acc_nb = 0
+    def reset_inner_loss(self):
+    # self.acc_attention = 0
+    # self.acc_nb = 0
 
-    def get_inner_loss(self):
-        # warnings.warn("l2 regularization", RuntimeWarning)
-        # return (self.acc_attention / self.acc_nb).pow(2).sum()
-        return torch.tensor([0], device=self.w_Q.device)
+    def get_inner_loss(self):
+    # warnings.warn("l2 regularization", RuntimeWarning)
+    # return (self.acc_attention / self.acc_nb).pow(2).sum()
+    # return torch.tensor([0], device=self.w_Q.device)
 
     def forward(self, bs):
         # Dimensions to make the source a bit clearer, that's needed
@@ -552,8 +559,8 @@ class Caterpillar(nn.Module):
             self.rec_K = X.new_zeros(N, R, T, DK)
             # We start the recurrent sequences with optimizable
             # initial values. No idea if it helps.
-            self.rec_V[:, :, t0 - L : t0] = self.init_V_rec[None, :, :, :]
-            self.rec_K[:, :, t0 - L : t0] = self.init_K_rec[None, :, :, :]
+            self.rec_V[:, :, t0 - L : t0, :] = self.init_V_rec[None, :, :, :]
+            self.rec_K[:, :, t0 - L : t0, :] = self.init_K_rec[None, :, :, :]
 
             self.cache_Y = X.new_zeros(N, T, DM)
 
@@ -576,95 +583,94 @@ class Caterpillar(nn.Module):
         # Clip the gating to avoid values greater than 1 when several
         # heads hit the same row
 
-        G = G / G.sum(1, keepdim=True).clamp(min=1)
-
-        ######################################################################
-        # Roll the gating indexes
-
-        # warnings.warn("rotating barrel", RuntimeWarning)
+        # G = G / G.sum(1, keepdim=True).clamp(min=1)
 
-        # r_barrel = torch.arange(R, device=G.device)[None, None, :, None]
-        # t_barrel = torch.arange(t1 - t0, device=G.device)[None, None, None, :]
-        # r_barrel = (r_barrel + (t_barrel + t0) // L) % R
-        # G = G.gather(dim=2, index=r_barrel.expand_as(G))
+        H = (1 - G).log().sum(1, keepdim=True).exp()
 
         ######################################################################
-        # The "flashbacks"
 
-        if self.training and self.proba_gate_dropout > 0.0:
-            # This is a better implementation of "flashbacks".
+        def recurrence(G, V, K):
+            # We prepare the arguments for the parallel scan
 
-            # G is NxHxExT where e is the caterpillar's row.
+            A = H
 
-            warnings.warn("gate dropout", RuntimeWarning)
-            epsilon = 0.5
+            gated_V = torch.einsum("nhrt,nhtd->nrtd", H * G / (1 - G), V)
+            gated_K = torch.einsum("nhrt,nhtd->nrtd", H * G / (1 - G), K)
 
-            dropout_head = (
-                (torch.rand(N, H, 1, t1 - t0, device=G.device).sort(dim=3).indices == 0)
-                .expand_as(G)
-                .float()
-            )
+            # We start from cached values, which matters in inference
 
-            dropout_tail = dropout_head.cumsum(dim=3) - dropout_head
+            init_rec_V = self.rec_V[:, :, t0 - L : t0]
+            init_rec_K = self.rec_K[:, :, t0 - L : t0]
 
-            dropout_active = (
-                torch.rand(N, 1, 1, 1, device=G.device) < self.proba_gate_dropout
-            ).long()
+            # Here there is a trick: Since the stack at position t is
+            # computed by updating that at position t-L, the parallel
+            # scan operates with a period of L. To do so we split the
+            # sequence indexing in two axes, the second of size L, and
+            # run the parallel scan using the first as the sequence index.
 
-            dropout_head *= dropout_active
-            dropout_tail *= dropout_active
+            A = A.unflatten(2, (-1, L))
+            gated_V = gated_V.unflatten(2, (-1, L))
+            gated_K = gated_K.unflatten(2, (-1, L))
 
-            G = (
-                G
-                + dropout_head * (1 - epsilon - G.detach())
-                - dropout_tail * G.detach()
-            )
+            next_V = pscan_dim(A, gated_V, init_rec_V, dim=2).flatten(2, 3)
+            next_K = pscan_dim(A, gated_K, init_rec_K, dim=2).flatten(2, 3)
 
-        ######################################################################
+            return next_V, next_K
 
-        # We prepare the arguments for the parallel scan
+        #################################################################
 
-        A = 1 - G.sum(1)
+        next_V, next_K = recurrence(G, V, K)
 
-        # warnings.warn("harmonic recurrence", RuntimeWarning)
-        # har = torch.arange(t0, t1, device = G.device).float() + 1
-        # A = har / (har + 1)
-        # G = G / har
+        if self.training and self.gate_dropout_proba > 0.0:
+            # G is NxHxRxT where r is the caterpillar's row.
 
-        gated_V = torch.einsum("nhrt,nhtd->nrtd", G, V)
-        gated_K = torch.einsum("nhrt,nhtd->nrtd", G, K)
+            warnings.warn("gate dropout", RuntimeWarning)
 
-        # We start from cached values, which matters in inference
+            if self.gate_dropout_sync:
+                shape_kill = (N, 1, 1)
+            else:
+                shape_kill = (N, H, R)
+
+            # Pick a point in each of the NxHxR timeline and set this
+            # entry and the following to 1
+            kill = (
+                torch.rand(*shape_kill, t1 - t0, device=G.device).sort(dim=3).indices
+                == 0
+            ).cumsum(dim=3)
+
+            # Keep these mask for only some of the NxHxR
+            kill = kill * (
+                torch.rand(*shape_kill, 1, device=G.device) <= self.gate_dropout_proba
+            )
 
-        init_rec_V = self.rec_V[:, :, t0 - L : t0]
-        init_rec_K = self.rec_K[:, :, t0 - L : t0]
+            # The coefficient to keep are the complementary
+            mask = 1 - kill
 
-        #################################################################
-        # Associative scan
+            masked_next_V, masked_next_K = recurrence(G * mask, V, K)
 
-        # Here there is a trick: Since the stack at position t is
-        # computed by updating that at position t-L, the parallel
-        # scan operates with a period of L. To do so we split the
-        # sequence indexing in two axes, the second of size L, and
-        # run the parallel scan using the first as the sequence index.
+            if self.gate_dropout_replace:
+                next_V = next_V.detach()
+                next_K = next_K.detach()
 
-        A = A.unflatten(2, (-1, L))
-        gated_V = gated_V.unflatten(2, (-1, L))
-        gated_K = gated_K.unflatten(2, (-1, L))
+            warnings.warn("the rescaling is probably a bad idea", RuntimeWarning)
 
-        next_V = pscan_dim(A, gated_V, init_rec_V, dim=2)
-        next_K = pscan_dim(A, gated_K, init_rec_K, dim=2)
+            next_V = next_V + (masked_next_V - masked_next_V.detach()) / (
+                1 - self.gate_dropout_proba
+            )
+            next_K = next_K + (masked_next_K - masked_next_K.detach()) / (
+                1 - self.gate_dropout_proba
+            )
 
-        self.rec_V[:, :, t0:t1] = next_V.flatten(2, 3)
-        self.rec_K[:, :, t0:t1] = next_K.flatten(2, 3)
+        self.rec_V[:, :, t0:t1] = next_V
+        self.rec_K[:, :, t0:t1] = next_K
 
         ######################################################################
         # compute the readout
 
         Q = torch.einsum("ntc,hdc->nhtd", X, self.w_Q)
 
-        # We build tensors NxHxTxFxL where N is the sample index, H
-        # the head, T the time, F the row in the caterpillar, and L
+        # We build tensors NxHxTxRxL where N is the sample index, H
+        # the head, T the time, R the row in the caterpillar, and L
         # the column in the caterpillar
 
         windowed_V = moving_window(
@@ -678,7 +684,7 @@ class Caterpillar(nn.Module):
         # We have an attention score for each of the RxL values
 
         ar = torch.einsum(
-            "nhtd,nftld->nhtfl",
+            "nhtd,nrtld->nhtrl",
             Q,
             windowed_K,
         ) / math.sqrt(DK)
@@ -718,7 +724,7 @@ class QKVAttention(nn.Module):
         causal=False,
         attention_dropout=0.0,
         logger=print,
-        **kwargs,
+        args=None,
     ):
         super().__init__()
 
@@ -809,9 +815,9 @@ class MyGPT(nn.Module):
         causal=False,
         dropout=0.0,
         len_max=1e5,
-        attention_layer="kvrec",
+        attention_layer="caterpillar",
         logger=print,
-        **kwargs,
+        args=None,
     ):
         super().__init__()
 
@@ -849,7 +855,7 @@ class MyGPT(nn.Module):
                     causal=causal,
                     attention_dropout=dropout,
                     logger=logger,
-                    **kwargs,
+                    args=args,
                 )
             elif attention_layer == "dumbrec":
                 return DumbRec(
@@ -860,7 +866,7 @@ class MyGPT(nn.Module):
                     nb_lines=nb_lines,
                     attention_dropout=dropout,
                     logger=logger,
-                    **kwargs,
+                    args=args,
                 )
             elif attention_layer == "kvrec":
                 return KVRec(
@@ -871,7 +877,7 @@ class MyGPT(nn.Module):
                     nb_lines=nb_lines,
                     attention_dropout=dropout,
                     logger=logger,
-                    **kwargs,
+                    args=args,
                 )
             elif attention_layer == "caterpillar":
                 return Caterpillar(
@@ -883,7 +889,7 @@ class MyGPT(nn.Module):
                     caterpillar_height=self.caterpillar_height,
                     attention_dropout=dropout,
                     logger=logger,
-                    **kwargs,
+                    args=args,
                 )
             else:
                 raise ValueError(f"Unknown attention type {attention_layer}.")
@@ -1014,7 +1020,111 @@ class MyGPT(nn.Module):
 ######################################################################
 
 if __name__ == "__main__":
-    print("Basic check.")
+    import argparse
+
+    import numpy as np
+    import matplotlib.pyplot as plt
+    import matplotlib.collections as mc
+
+    args = argparse.Namespace(
+        gate_dropout_proba=0.0, gate_dropout_sync=True, gate_dropout_replace=False
+    )
+
+    device = torch.device("cuda" if torch.cuda.is_available() else "cpu")
+
+    dim_model, dim_keys, nb_heads = 512, 64, 1
+    dropout = 0.1
+
+    caterpillar = Caterpillar(
+        dim_model=dim_model,
+        dim_qk=dim_keys,
+        dim_v=dim_model // nb_heads,
+        nb_heads=nb_heads,
+        caterpillar_length=16,
+        caterpillar_height=32,
+        attention_dropout=dropout,
+        args=args,
+    ).to(device)
+
+    qkv = QKVAttention(
+        dim_model=dim_model,
+        dim_qk=dim_keys,
+        dim_v=dim_model // nb_heads,
+        nb_heads=nb_heads,
+        causal=True,
+        attention_dropout=dropout,
+        args=args,
+    ).to(device)
+
+    linear = CacheWrapper(nn.Linear(512, 512)).to(device)
+
+    x = torch.randn(1, 256, dim_model)
+
+    x = x.to(device)
+    x.requires_grad_()
+
+    ######################################################################
+
+    fig = plt.figure()
+    fig.set_figheight(6)
+    fig.set_figwidth(8)
+
+    ax = fig.add_subplot(1, 1, 1)
+
+    # ax.set_xlim(-1.5, 1.5)
+    # ax.set_ylim(-1.5, 1.5)
+    # ax.set(aspect=1)
+    # ax.spines.right.set_visible(False)
+    # ax.spines.top.set_visible(False)
+
+    # dt = 0.01
+    # t = np.arange(dt, 20.0, dt)
+    # ax.semilogx(t, np.exp(-t / 5.0))
+    # ax.grid()
+
+    ######################################################################
+
+    for label, model in [
+        # ("nn.Linear", linear),
+        ("mygpy.QKVAttention", qkv),
+        ("mygpt.Caterpillar", caterpillar),
+    ]:
+        y = model(BracketedSequence(x, 32, x.size(1) - 32, init_cache=True)).x
+
+        data = []
+        for t in range(y.size(1)):
+            for d in torch.randperm(y.size(2))[:8]:
+                g = torch.autograd.grad(y[0, t, d], x, retain_graph=True)[0]
+                sg = g.pow(2).sum().item()
+                # sg = 0
+                # for p in model.parameters():
+                # g = torch.autograd.grad(y[0, t, d], p, retain_graph=True)[0]
+                # sg = sg + g.pow(2).sum().item()
+                data.append([t, sg])
+
+        data = torch.tensor(data)
+        ax.scatter(
+            data[:, 0], data[:, 1], s=1, label=label
+        )  # , color='gray', label='Input')
+
+    # ax.legend(frameon=False, loc="top right")
+
+    # Put a legend to the right of the current axis
+    box = ax.get_position()
+    ax.set_position([box.x0, box.y0, box.width * 0.8, box.height])
+    ax.legend(loc="center left", bbox_to_anchor=(1, 0.5))
+
+    filename = "plot.pdf"
+    print(f"saving {filename}")
+    fig.savefig(filename, bbox_inches="tight")
+
+    # if args.window and hasattr(plt.get_current_fig_manager(), 'window'):
+    # plt.get_current_fig_manager().window.setGeometry(2, 2, 1024, 768)
+    # plt.show()
+
+    exit(0)
+
+    ######################################################################
 
     m = Caterpillar(
         dim_model=4,
@@ -1036,8 +1146,6 @@ if __name__ == "__main__":
     print((y1 - torch.cat([y3a, y3b], dim=1)).abs().max())
     exit(0)
 
-    device = torch.device("cuda" if torch.cuda.is_available() else "cpu")
-
     vocabulary_size = 128
     x = torch.randint(vocabulary_size, (6, 1024))