Fig. 9From: Predictive modeling of Persian walnut (Juglans regia L.) in vitro proliferation media using machine learning approaches: a comparative study of ANN, KNN and GEP modelsObserved vs. predicted values of vitrification (Vit) related to A multiple linear regression (MLR); B multi-layer perceptron neural network (MLPNN); C k-nearest neighbors (KNN); D gene expression programming (GEP) developed models (n = 224) for walnut cv. RayenBack to article page