Merge pull request #112 from flucoma/feature/invert-pca

Feature/invert pca

Author: tedmoore

include/algorithms/public/PCA.hpp

@@ -58,6 +58,14 @@ class PCA
     out = _impl::asFluid(result);
   }
 
+  void inverseProcessFrame(RealVectorView in, RealVectorView out) const
+  {
+    using namespace Eigen;
+    using namespace _impl;
+    asEigen<Matrix>(out) = mMean + (asEigen<Matrix>(in).transpose() * mBases.transpose()).transpose();
+  }
+    
+    
   double process(const RealMatrixView in, RealMatrixView out, index k) const
   {
     using namespace Eigen;

include/clients/nrt/PCAClient.hpp

@@ -128,6 +128,28 @@ class PCAClient : public FluidBaseClient,
     outBuf.samps(0, k, 0) = dest;
     return OK();
   }
+  
+  MessageResult<void> inverseTransformPoint(BufferPtr in, BufferPtr out) const
+  {
+    if (!mAlgorithm.initialized()) return Error(NoDataFitted);
+    InOutBuffersCheck bufCheck(mAlgorithm.dims());
+    BufferAdaptor::Access inBuf(in.get());
+    BufferAdaptor::Access outBuf(out.get());
+    if(!inBuf.exists()) return Error("Input buffer not found");
+    if(!inBuf.valid()) return Error("Input buffer may be zero sized");
+    if(!outBuf.exists()) return Error("Output buffer not found");
+        
+    FluidTensor<double, 1> src(mAlgorithm.dims());
+    FluidTensor<double, 1> dst(mAlgorithm.dims());
+    index k = std::min(inBuf.numFrames(),mAlgorithm.dims());
+    
+    src(Slice(0,k)) = inBuf.samps(0,k,0);
+    Result resizeResult = outBuf.resize(mAlgorithm.dims(), 1, outBuf.sampleRate());
+    
+    mAlgorithm.inverseProcessFrame(src,dst);
+    outBuf.samps(0,mAlgorithm.dims(),0) = dst;
+    return OK();
+  }
 
   static auto getMessageDescriptors()
   {
@@ -136,6 +158,7 @@ class PCAClient : public FluidBaseClient,
         makeMessage("transform", &PCAClient::transform),
         makeMessage("fitTransform", &PCAClient::fitTransform),
         makeMessage("transformPoint", &PCAClient::transformPoint),
+        makeMessage("inverseTransformPoint", &PCAClient::inverseTransformPoint),
         makeMessage("cols", &PCAClient::dims),
         makeMessage("size", &PCAClient::size),
         makeMessage("clear", &PCAClient::clear),