Table 5. Discretization of the gene expression change.

	Cond1	Cond2	Cond3	Cond4	Cond5	Cond6	Cond7
A	↑	↑	↑	↑	—	↓	↓
B	↑	↑	↑	↑	↓	↓	↓
C	↑	—	—	↑	↓	↓	↓

If the change of the level of expression reported in Table 4 is larger than a given threshold T ₀, we write an arrow pointing upwards (↑), whereas if the change of the level of expression is smaller than −T ₀ then we write an arrow pointing downwards (↓). The symbol (—) indicates that no significant change was detected. In this example we used a threshold T ₀ = 1.5 to discretize the numbers given in Table 4.