2026-07-072026-07-07http://salesiana.dossiersoluciones.com/handle/123456789/176080We report on INTEGRAL observations performed during the 2004 outburst of the bright black hole transient GX 339-4. We analysed IBIS and JEM-X public data starting on 9th August and lasting about one month. During this period GX 339-4 showed spectral state transitions. In order to seek for variability patterns, a principal component analysis (PCA) has been used.5 pages, 6 figures, accepted for publication in the proceedings of VI Microquasar workshop: Microquasar and Beyond, 18-22 September 2006 in Como (Italy), eds: T. Belloni et al. (2006)AstrophysicsSpectral variability modes of GX 339-4 in a hard-to-soft state transitiontext