How And When To Harvest. Harvest looseleaf lettuce by 2 methods. The best way is to start picking the outer leaves of each plant when they get to be 2 to 3 inches long. Continue picking this way for 4 to 6 weeks until the plant goes to seed (the flower spike grows up out of the center--also called âbolting.â).
Blinders prevent you from seeing to the side and force you to focus on what's in front of you. A cofactor is the number you get when you remove the column and row of a designated element in a matrix, which is just a numerical grid in the form of a rectangle or a square. The cofactor is always preceded by a positive (+) or negative (-) sign, depending whether the element is in a + or - position.
In other words, covariance is a measure of the strength of the correlation between two random variables. In another perspective, it can be seen that correlation is just the normalized version of covariance, where the covariance is divided by the product of the standard deviations of the two random variables.