detrend1 This function removes the best fit of a polynomial of order P from the data X detrend1(X,P) X: Input vecor or matrix. P: The order of polnomial If X is a vector, 'detrend1(X, P)' removes the best fit of apolynomial of order P from the data X.If X is a matrix, 'detrend1(X, P)' does the same for each column in X. The second argument P is optional. If it is not specified, a value of 1 is assumed. This corresponds to removing a linear trend. The order of the polynomial can also be given as a string, in which case P must be either "constant" (corresponds to 'P=0') or "linear"(corresponds to 'P=1')