mean

mean(X)

Calculate the average of X.

• If X is a matrix, calculate the average of each column and return a vector.

• If X is a table, calculate the average of each column and return a table.

This function is equivalent to avg.

The calculation skips null values.

The DolphinDB mean function operates on vectors, matrices, and tables. For matrices and tables, it calculates the column mean by default. There is no concept of a "global mean"; if you need it, you need to flatten the data manually. NumPy's mean function is designed for multi-dimensional arrays. By default, it flattens the input into a one-dimensional array and computes the global mean. To compute along rows, columns, or multiple axes, you need to explicitly specify the axis parameter.

X is a scalar/vector/matrix/table.

• If X is a vector, returns a DOUBLE scalar.

• If X is a matrix, returns a DOUBLE vector.

• If X is a table, returns a table.

x=1 5 9;
mean(x);
// output: 5

x=1 5 9 NULL;
mean(x);
// output: 5

avg(x);
// output: 5

m=matrix(1 2 3, 4 5 6);
m;

mean(m);
// output: [2,5]

Related center data tendency functions: mode, med