diff --git a/src/PartialLeastSquaresRegressor.jl b/src/PartialLeastSquaresRegressor.jl
index fa1591a..9cf19e9 100644
--- a/src/PartialLeastSquaresRegressor.jl
+++ b/src/PartialLeastSquaresRegressor.jl
@@ -9,6 +9,7 @@ include("types.jl")
 include("pls1.jl")
 include("pls2.jl")
 include("kpls.jl")
+include("opls.jl")
 include("method.jl")
 include("mlj_interface.jl")
 
diff --git a/src/opls.jl b/src/opls.jl
new file mode 100644
index 0000000..59e62d6
--- /dev/null
+++ b/src/opls.jl
@@ -0,0 +1,53 @@
+# based on the code from https://github.com/BiRG/pyopls
+# reference:  Johan Trygg and Svante Wold. Orthogonal projections to latent structures (O-PLS). 
+#             J. Chemometrics 2002; 16: 119-128. DOI: 10.1002/cem.695
+
+
+
+##filtering and learning - Ortogonal PLS, one feature
+function fitting(model::OPLS1Model,
+    X::AbstractArray{T}, 
+    Y::Vector{T}) where T<:AbstractFloat
+    
+    w=X'*Y         # calculate weight vector
+    w=w/norm(w)    # normalization
+
+    for i in 1:model.n_ortho_components
+        t=X*w                     # calculate scores vector  nrows
+        p=X'*t/(t'*t)             # calculate loadings of X  ncols
+        wosc=p-(w'*p)/(w'*w)*w    # orthogonal weight        ncols
+        wosc=wosc/norm(wosc)      # normalization            ncols
+        tosc=X*wosc               # orthogonal components    nrows
+        posc=X'*tosc/(tosc'*tosc) # loadings                 ncols
+        
+        X=X-tosc*posc'             # remove orthogonal components
+
+        model.W_ortho[:,i]=wosc    # weights orthogonal to y
+        model.P_ortho[:,i]=posc    # loadings orthogonal to y
+        model.T_ortho[:,i]=tosc    # scores orthogonal to y
+    end
+
+    # X is now with orthogonal signal components removed
+    return X, model.T_ortho
+end
+
+# remove orthogonal components from Xt
+# return filtered Xt and weightings of orthogonal components
+function filter!(model::OPLS1Model,
+    X::AbstractArray{T}) where T<:AbstractFloat
+    nrow = size(X,1)
+    # ortogonal weights
+    ortho = zeros(T, nrow, model.n_ortho_components)
+
+    for i in 1:model.n_ortho_components
+        R = X * model.W_ortho[:,i]
+        X = X - R * model.P_ortho[:,i]'
+        ortho[:,i] = R
+    end
+
+    return X, ortho
+end
+
+function component(model::OPLS1Model{T},i) where T<:AbstractFloat
+    return model.W_ortho[:,i]
+end
\ No newline at end of file
diff --git a/src/pls1.jl b/src/pls1.jl
index d92f1dc..a08f0dc 100644
--- a/src/pls1.jl
+++ b/src/pls1.jl
@@ -40,3 +40,23 @@ function predictor(model::PLS1Model{T},
 
     return Y
 end
+
+function filter!(model::PLS1Model{T},
+    X::AbstractArray{T}) where T<:AbstractFloat
+
+    nrows  = size(X,1)
+    X_proj = zeros(T, nrows, model.nfactors)
+    Y_pred = zeros(size(X,1))
+
+    for i = 1:model.nfactors
+        X_proj[:,i] = X*model.W[:,i]
+        X           = X - X_proj[:,i]*model.P[:,i]'
+        Y_pred      = Y_pred + X_proj[:,i]*model.b[i] # building prediction
+    end
+
+    return X, X_proj, Y_pred
+end
+
+function component(model::PLS1Model{T},i) where T<:AbstractFloat
+    return model.W[:,i]
+end
\ No newline at end of file
diff --git a/src/pls2.jl b/src/pls2.jl
index df9be5f..0609178 100644
--- a/src/pls2.jl
+++ b/src/pls2.jl
@@ -61,3 +61,27 @@ function predictor(model::PLS2Model{T},
     return Y
 end
 
+function filter!(model::PLS2Model{T},
+    X::AbstractArray{T}) where T<:AbstractFloat
+
+    nrows  = size(X,1)
+    X_proj = zeros(T, nrows, model.nfactors)
+
+    W,Q,P      = model.W,model.Q,model.P
+    nfactors   = model.nfactors
+    Y          = zeros(T,size(X,1),model.ntargetcols)
+    #println("nfactors: ",nfactors)
+    for i = 1:nfactors
+        #R      = X*W[:,i]
+        X_proj[:,i] = X*model.W[:,i]
+        X      = X - X_proj[:,i] * P[:,i]'
+        Y      = Y + X_proj[:,i] * Q[:,i]'
+    end
+
+    return X,X_proj,Y
+end
+
+
+function component(model::PLS2Model{T},i) where T<:AbstractFloat
+    return model.W[:,i]
+end
\ No newline at end of file
diff --git a/src/types.jl b/src/types.jl
index 60d1909..f525013 100644
--- a/src/types.jl
+++ b/src/types.jl
@@ -93,3 +93,30 @@ function PLSModel(X::Matrix{T},
             kernel,
             width)
 end
+
+
+################################################################################
+#### OPLS1 type
+mutable struct OPLS1Model{T<:AbstractFloat} <:PLSModel{T}
+    W_ortho::Matrix{T} # : weights orthogonal to y
+    P_ortho::Matrix{T} # : loadings orthogonal to y
+    T_ortho::Matrix{T} # : scores orthogonal to y
+
+    n_ortho_components::Int  #  
+end
+
+## OPLS1: constructor
+function OPLS1Model(X::Matrix{T},
+    Y::Vector{T},
+    n_components::Int) where T<:AbstractFloat
+
+    (nrows,ncols) = size(X)
+
+    ## Allocation
+    return OPLS1Model(
+        zeros(T, ncols, n_components), ## W_ortho
+        zeros(T, ncols, n_components), ## P_ortho
+        zeros(T, nrows, n_components), ## T_ortho
+        n_components                   ## n_components
+        )
+end
\ No newline at end of file
diff --git a/test/Project.toml b/test/Project.toml
new file mode 100644
index 0000000..4524baa
--- /dev/null
+++ b/test/Project.toml
@@ -0,0 +1,8 @@
+[deps]
+MLJBase = "a7f614a8-145f-11e9-1d2a-a57a1082229d"
+MLJModelInterface = "e80e1ace-859a-464e-9ed9-23947d8ae3ea"
+Random = "9a3f8284-a2c9-5f02-9a11-845980a1fd5c"
+ScientificTypes = "321657f4-b219-11e9-178b-2701a2544e81"
+ScientificTypesBase = "30f210dd-8aff-4c5f-94ba-8e64358c1161"
+Statistics = "10745b16-79ce-11e8-11f9-7d13ad32a3b2"
+Test = "8dfed614-e22c-5e08-85e1-65c5234f0b40"