sample

Arguments

n

positive integer (size of sample)

X

matrix. Samples will be extracted from this matrix.

orient

Optional parameter. Admissible values are {'*'}, 1, 2, 'r' or 'c'. The orientation to sample rows or columns. See Description below.

s

vector or matrix containing sample

Description

This function returns a vector or matrix. It contains a random sample of n extractions, with replacement, from the matrix X.

s = sample(n, X) (or s = sample(n, X, '*')) returns a vector s whose values are a random sample of n values, extracted with replacement, from X.

s = sample(n, X, 'r') (or, equivalently, s = sample(n, X, 1)) returns a matrix of size size(X,'r') * n. It contains a random sample of n rows, extracted with replacement, from the rows of X.

s = sample(n, X, 'c') (or, equivalently, s = sample(n, X, 2)) returns a matrix of size n * size(X, 'c'). It contains a random sample of n columns, extracted with replacement from the columns of X.

Random number generator

sample is based on grand for generating the random samples. Use grand("setsd", seed) to change the seed for samplef.

seed = getdate("s");
grand("setsd", seed); //sets the seed to current date

seed = 0;
grand("setsd", seed); //sets the seed to default value

Examples

X = ['a' 'dd' 'arreu'; 'ber' 'car' 'zon']
s = sample(25, X)
s = sample(25, X, 'r')
s = sample(25, X, 'c')

See also

• samplef — sample values with replacement from a population with given frequencies.
• samwr — Sampling without replacement
• grand — Random numbers