public void InitData(IDataset ds, int nhidden, Intarray newc2i = null, Intarray newi2c = null)
{
CHECK_ARG(nhidden > 1 && nhidden < 1000000, "nhidden > 1 && nhidden < 1000000");
int ninput = ds.nFeatures();
int noutput = ds.nClasses();
w1.Resize(nhidden, ninput);
b1.Resize(nhidden);
w2.Resize(noutput, nhidden);
b2.Resize(noutput);
Intarray indexes = new Intarray();
NarrayUtil.RPermutation(indexes, ds.nSamples());
Floatarray v = new Floatarray();
for (int i = 0; i < w1.Dim(0); i++)
{
int row = indexes[i];
ds.Input1d(v, row);
float normv = (float)NarrayUtil.Norm2(v);
v /= normv * normv;
NarrayRowUtil.RowPut(w1, i, v);
}
ClassifierUtil.fill_random(b1, -1e-6f, 1e-6f);
ClassifierUtil.fill_random(w2, -1.0f / nhidden, 1.0f / nhidden);
ClassifierUtil.fill_random(b2, -1e-6f, 1e-6f);
if (newc2i != null)
{
c2i.Copy(newc2i);
}
if (newi2c != null)
{
i2c.Copy(newi2c);
}
}
public override float OutputsDense(Floatarray result, Floatarray x_raw)
{
CHECK_ARG(x_raw.Length() == w1.Dim(1), "x_raw.Length() == w1.Dim(1)");
Floatarray z = new Floatarray();
int sparse = PGeti("sparse");
Floatarray y = new Floatarray();
Floatarray x = new Floatarray();
x.Copy(x_raw);
mvmul0(y, w1, x);
y += b1;
for (int i = 0; i < y.Length(); i++)
{
y[i] = sigmoid(y[i]);
}
if (sparse > 0)
{
ClassifierUtil.Sparsify(y, sparse);
}
mvmul0(z, w2, y);
z += b2;
for (int i = 0; i < z.Length(); i++)
{
z[i] = sigmoid(z[i]);
}
result.Copy(z);
//int idx = NarrayUtil.ArgMax(result);
//float val = NarrayUtil.Max(result);
return(Convert.ToSingle(Math.Abs(NarrayUtil.Sum(z) - 1.0)));
}
/// <summary>
/// Train on a text line.
/// <remarks>Usage is: call addTrainingLine with training data, then call finishTraining
/// The state of the object is undefined between calling addTrainingLine and finishTraining, and it is
/// an error to call recognizeLine before finishTraining completes. This allows both batch
/// and incemental training.
/// NB: you might train on length 1 strings for single character training
/// and might train on words if line alignment is not working
/// (well, for some training data)</remarks>
/// </summary>
public void AddTrainingLine(Intarray cseg, string tr)
{
Bytearray gimage = new Bytearray();
ClassifierUtil.segmentation_as_bitmap(gimage, cseg);
AddTrainingLine(cseg, gimage, tr);
}
public override void TrainDense(IDataset ds)
{
//PSet("%nsamples", ds.nSamples());
float split = PGetf("cv_split");
int mlp_cv_max = PGeti("cv_max");
if (crossvalidate)
{
// perform a split for cross-validation, making sure
// that we don't have the same sample in both the
// test and the training set (even if the data set
// is the result of resampling)
Intarray test_ids = new Intarray();
Intarray ids = new Intarray();
for (int i = 0; i < ds.nSamples(); i++)
{
ids.Push(ds.Id(i));
}
NarrayUtil.Uniq(ids);
Global.Debugf("cvdetail", "reduced {0} ids to {1} ids", ds.nSamples(), ids.Length());
NarrayUtil.Shuffle(ids);
int nids = (int)((1.0 - split) * ids.Length());
nids = Math.Min(nids, mlp_cv_max);
for (int i = 0; i < nids; i++)
{
test_ids.Push(ids[i]);
}
NarrayUtil.Quicksort(test_ids);
Intarray training = new Intarray();
Intarray testing = new Intarray();
for (int i = 0; i < ds.nSamples(); i++)
{
int id = ds.Id(i);
if (ClassifierUtil.Bincontains(test_ids, id))
{
testing.Push(i);
}
else
{
training.Push(i);
}
}
Global.Debugf("cvdetail", "#training {0} #testing {1}",
training.Length(), testing.Length());
PSet("%ntraining", training.Length());
PSet("%ntesting", testing.Length());
Datasubset trs = new Datasubset(ds, training);
Datasubset tss = new Datasubset(ds, testing);
TrainBatch(trs, tss);
}
else
{
TrainBatch(ds, ds);
}
}
protected void InitRandom(int ninput, int nhidden, int noutput)
{
w1.Resize(nhidden, ninput);
b1.Resize(nhidden);
w2.Resize(noutput, nhidden);
b2.Resize(noutput);
float range = 1.0f / Math.Max(ninput, nhidden);
ClassifierUtil.fill_random(w1, -range, range);
ClassifierUtil.fill_random(b1, -range, range);
ClassifierUtil.fill_random(w2, -range, range);
ClassifierUtil.fill_random(b2, -range, range);
}
/// <summary>
/// do a single stochastic gradient descent step
/// </summary>
public void TrainOne(Floatarray z, Floatarray target, Floatarray x, float eta)
{
CHECK_ARG(target.Length() == w2.Dim(0), "target.Length() == w2.Dim(0)");
CHECK_ARG(x.Length() == w1.Dim(1), "x.Length() == w1.Dim(1)");
int sparse = PGeti("sparse");
int nhidden = this.nHidden();
int noutput = nClasses();
Floatarray delta1 = new Floatarray(nhidden);
Floatarray delta2 = new Floatarray(noutput);
Floatarray y = new Floatarray(nhidden);
mvmul0(y, w1, x);
y += b1;
for (int i = 0; i < nhidden; i++)
{
y[i] = sigmoid(y[i]);
}
if (sparse > 0)
{
ClassifierUtil.Sparsify(y, sparse);
}
mvmul0(z, w2, y);
z += b2;
for (int i = 0; i < noutput; i++)
{
z[i] = sigmoid(z[i]);
}
for (int i = 0; i < noutput; i++)
{
delta2[i] = (z[i] - target[i]) * dsigmoidy(z[i]);
}
vmmul0(delta1, delta2, w2);
for (int i = 0; i < nhidden; i++)
{
delta1[i] = delta1[i] * dsigmoidy(y[i]);
}
outer_add(w2, delta2, y, -eta);
for (int i = 0; i < noutput; i++)
{
b2[i] -= eta * delta2[i];
}
outer_add(w1, delta1, x, -eta);
for (int i = 0; i < nhidden; i++)
{
b1[i] -= eta * delta1[i];
}
}
public void ChangeHidden(int newn)
{
MlpClassifier temp = new MlpClassifier();
int ninput = w1.Dim(1);
int nhidden = w1.Dim(0);
int noutput = w2.Dim(0);
temp.InitRandom(ninput, newn, noutput);
for (int i = 0; i < newn; i++)
{
if (i >= nhidden)
{
for (int j = 0; j < ninput; j++)
{
temp.w1[i, j] = ClassifierUtil.rNormal(0.0f, 1.0f);
}
temp.b1[i] = ClassifierUtil.rNormal(0.0f, 1.0f);
}
else
{
for (int j = 0; j < ninput; j++)
{
temp.w1[i, j] = w1[i, j];
}
temp.b1[i] = b1[i];
}
}
for (int i = 0; i < noutput; i++)
{
for (int j = 0; j < newn; j++)
{
if (j >= nhidden)
{
temp.w2[i, j] = 1e-2f * ClassifierUtil.rNormal(0.0f, 1.0f);
}
else
{
temp.w2[i, j] = w2[i, j];
}
}
}
this.Copy(temp);
}
public virtual void TrainBatch(IDataset ds, IDataset ts)
{
Stopwatch sw = Stopwatch.StartNew();
bool parallel = PGetb("parallel");
float eta_init = PGetf("eta_init"); // 0.5
float eta_varlog = PGetf("eta_varlog"); // 1.5
float hidden_varlog = PGetf("hidden_varlog"); // 1.2
int hidden_lo = PGeti("hidden_lo");
int hidden_hi = PGeti("hidden_hi");
int rounds = PGeti("rounds");
int mlp_noopt = PGeti("noopt");
int hidden_min = PGeti("hidden_min");
int hidden_max = PGeti("hidden_max");
CHECK_ARG(hidden_min > 1 && hidden_max < 1000000, "hidden_min > 1 && hidden_max < 1000000");
CHECK_ARG(hidden_hi >= hidden_lo, "hidden_hi >= hidden_lo");
CHECK_ARG(hidden_max >= hidden_min, "hidden_max >= hidden_min");
CHECK_ARG(hidden_lo >= hidden_min && hidden_hi <= hidden_max, "hidden_lo >= hidden_min && hidden_hi <= hidden_max");
int nn = PGeti("nensemble");
ObjList <MlpClassifier> nets = new ObjList <MlpClassifier>();
nets.Resize(nn);
for (int i = 0; i < nn; i++)
{
nets[i] = new MlpClassifier(i);
}
Floatarray errs = new Floatarray(nn);
Floatarray etas = new Floatarray(nn);
Intarray index = new Intarray();
float best = 1e30f;
if (PExists("%error"))
{
best = PGetf("%error");
}
int nclasses = ds.nClasses();
/*Floatarray v = new Floatarray();
* for (int i = 0; i < ds.nSamples(); i++)
* {
* ds.Input1d(v, i);
* CHECK_ARG(NarrayUtil.Min(v) > -100 && NarrayUtil.Max(v) < 100, "min(v)>-100 && max(v)<100");
* }*/
CHECK_ARG(ds.nSamples() >= 10 && ds.nSamples() < 100000000, "ds.nSamples() >= 10 && ds.nSamples() < 100000000");
for (int i = 0; i < nn; i++)
{
// nets(i).init(data.dim(1),logspace(i,nn,hidden_lo,hidden_hi),nclasses);
if (w1.Length() > 0)
{
nets[i].Copy(this);
etas[i] = ClassifierUtil.rLogNormal(eta_init, eta_varlog);
}
else
{
nets[i].InitData(ds, (int)(logspace(i, nn, hidden_lo, hidden_hi)), c2i, i2c);
etas[i] = PGetf("eta");
}
}
etas[0] = PGetf("eta"); // zero position is identical to itself
Global.Debugf("info", "mlp training n {0} nc {1}", ds.nSamples(), nclasses);
for (int round = 0; round < rounds; round++)
{
Stopwatch swRound = Stopwatch.StartNew();
errs.Fill(-1);
if (parallel)
{
// For each network i
Parallel.For(0, nn, i =>
{
nets[i].PSet("eta", etas[i]);
nets[i].TrainDense(ds); // было XTrain
errs[i] = ClassifierUtil.estimate_errors(nets[i], ts);
});
}
else
{
for (int i = 0; i < nn; i++)
{
nets[i].PSet("eta", etas[i]);
nets[i].TrainDense(ds); // было XTrain
errs[i] = ClassifierUtil.estimate_errors(nets[i], ts);
//Global.Debugf("detail", "net({0}) {1} {2} {3}", i,
// errs[i], nets[i].Complexity(), etas[i]);
}
}
NarrayUtil.Quicksort(index, errs);
if (errs[index[0]] < best)
{
best = errs[index[0]];
cv_error = best;
this.Copy(nets[index[0]]);
this.PSet("eta", etas[index[0]]);
Global.Debugf("info", " best mlp[{0}] update errors={1} {2}", index[0], best, crossvalidate ? "cv" : "");
}
if (mlp_noopt == 0)
{
for (int i = 0; i < nn / 2; i++)
{
int j = i + nn / 2;
nets[index[j]].Copy(nets[index[i]]);
int n = nets[index[j]].nHidden();
int nm = Math.Min(Math.Max(hidden_min, (int)(ClassifierUtil.rLogNormal(n, hidden_varlog))), hidden_max);
nets[index[j]].ChangeHidden(nm);
etas[index[j]] = ClassifierUtil.rLogNormal(etas[index[i]], eta_varlog);
}
}
Global.Debugf("info", " end mlp round {0} err {1} nHidden {2}", round, best, nHidden());
swRound.Stop();
int totalTest = ts.nSamples();
int errCnt = Convert.ToInt32(best * totalTest);
OnTrainRound(this, new TrainEventArgs(
round, best, totalTest - errCnt, totalTest, best, swRound.Elapsed, TimeSpan.Zero
));
}
sw.Stop();
Global.Debugf("info", String.Format(" training time: {0} minutes, {1} seconds",
(int)sw.Elapsed.TotalMinutes, sw.Elapsed.Seconds));
PSet("%error", best);
int nsamples = ds.nSamples() * rounds;
if (PExists("%nsamples"))
{
nsamples += PGeti("%nsamples");
}
PSet("%nsamples", nsamples);
}