Fig. 1. Flow chart of fuzzy C-clustering method based on UMAP assisted

Fig. 2. Principle of the terahertz time-domain spectroscopy system

Fig. 3. Time domain diagram of four transgenic cotton seeds

Fig. 4. Frequency domain diagram of four transgenic cotton seeds

Fig. 5. The absorbance of four transgenic cotton seeds

Fig. 6. Clustering result of different dimensionality reduction methods (3D)
(a): Clustering result of PCA; (b): Clustering result of LLE; (c): Clustering result of LPP; (d): Clustering result of UMAP

Fig. 7. Selection of cluster centers

Fig. 8. Clustering result of FCM assisted by different dimensionality reduction methods (3D)
(a): Clustering result of PCA-assisted FCM; (b): Clustering result of LLE-assisted FCM; (c): Clustering result of LPP-assisted FCM; (d): Clustering result of UMAP-assisted FCM