• Laser & Optoelectronics Progress
  • Vol. 56, Issue 13, 131102 (2019)
Xiu Jin, Xianzhi Zhu, Shaowen Li*, Wencai Wang, and Haijun Qi
Author Affiliations
  • School of Information & Computer, Anhui Agricultural University, Hefei, Anhui 230036, China
  • show less
    DOI: 10.3788/LOP56.131102 Cite this Article Set citation alerts
    Xiu Jin, Xianzhi Zhu, Shaowen Li, Wencai Wang, Haijun Qi. Predicting Soil Available Phosphorus by Hyperspectral Regression Method Based on Gradient Boosting Decision Tree[J]. Laser & Optoelectronics Progress, 2019, 56(13): 131102 Copy Citation Text show less
    Stacking method
    Fig. 1. Stacking method
    Indoor hyperspectral acquisition system
    Fig. 2. Indoor hyperspectral acquisition system
    Hyperspectral reflectance of soil. (a) Original spectra; (b) smoothing spectra
    Fig. 3. Hyperspectral reflectance of soil. (a) Original spectra; (b) smoothing spectra
    fRMSE values of different LV numbers in linear and nonlinear PLS
    Fig. 4. fRMSE values of different LV numbers in linear and nonlinear PLS
    Parameter optimization of GBDT model. (a) Rloss=Fls, Rn_estimators=100; (b) Rloss=Fhuber, Rn_estimators=200; (c) Rloss=Fquantile, Rn_estimators=200; (d) Rloss=Flad, Rn_estimators=310
    Fig. 5. Parameter optimization of GBDT model. (a) Rloss=Fls, Rn_estimators=100; (b) Rloss=Fhuber, Rn_estimators=200; (c) Rloss=Fquantile, Rn_estimators=200; (d) Rloss=Flad, Rn_estimators=310
    Results of different model integration algorithms. (a) Results of random forest based on modeling set; (b) results of random forest based on testing set; (c) results of boosting tree based on modeling set; (d) results of boosting tree based on testing set; (e) results of GBDT based on modeling set; (f) results of GBDT based on testing set
    Fig. 6. Results of different model integration algorithms. (a) Results of random forest based on modeling set; (b) results of random forest based on testing set; (c) results of boosting tree based on modeling set; (d) results of boosting tree based on testing set; (e) results of GBDT based on modeling set; (f) results of GBDT based on testing set
    TypeSampleMax /(mg·kg-1)Min /(mg·kg-1)Average /(mg·kg-1)Standard deviation /(mg·kg-1)
    Total19334.960.0310.569.36
    Training14434.960.0310.949.49
    Testing4932.240.609.018.99
    Table 1. Statistical parameters of soil available phosphorus content
    Modeling methodTraining setTesting setPrediction level(testing set)Parameter
    fRPDR2fRPDR2
    PLS1.660.731.650.68BRLVs=11
    RBF-PLS1.580.711.790.73BRLVs=11, Rgamma =0.016
    Sigmoid-PLS1.550.701.750.73BRLVs =10, Rgamma=0.00085,Rcofe0cofe0=4.5
    SVR1.600.741.530.69BC=10000
    RBF-SVR1.700.761.660.72BC=2000000, Rgamma =0.0028
    Sigmoid-SVR1.590.731.550.70BC=1011, Rgamma =0.000001,Rcofe0=0
    Ridge1.600.741.500.69BRAlpha=0.001
    RBF-Ridge1.550.741.500.70BRAlpha=0.00006, Rgamma =0.01
    Sigmoid-Ridge1.520.721.500.69BRAlpha=4×10-7,Rgamma =0.0005, Rcofe0=0.9
    Table 2. Testing results of optimal single model
    Ensemble methodTraining setTesting setPrediction level(testing set)Parameter
    fRPDR2fRPDR2
    Random forest2.100.842.080.84ARn_estimators, Rmax_depth=5
    Boosting tree2.860.902.120.82ARn_estimators =300, Rlearning_rate=0.01,Rmax_depth=5, Rloss=Flinear
    GBDT2.560.882.550.86ARn_estimators =310, Rlearning_rate=0.29,Rmax_depth=4, Rloss=Flad
    Table 3. Results of multi-model combination
    Xiu Jin, Xianzhi Zhu, Shaowen Li, Wencai Wang, Haijun Qi. Predicting Soil Available Phosphorus by Hyperspectral Regression Method Based on Gradient Boosting Decision Tree[J]. Laser & Optoelectronics Progress, 2019, 56(13): 131102
    Download Citation