Student[Statistics]
Sample
generate random sample
Calling Sequence
Parameters
Description
Computation
Examples
References
Compatibility
Sample(X, n, numeric_option, output_option)
X
-
algebraic; random variable
n
positive integer; sample size
numeric_option
(optional) equation of the form numeric=value where value is true or false
output_option
(optional) equation of the form output=x where x is value, plot, or both
The Sample command generates a random sample drawn from the distribution given by X.
The first parameter, X, can be a random variable, or an algebraic expression involving random variables (see Student[Statistics][RandomVariable]).
The second parameter, n, is the sample size. The function will return a newly created Vector of length n, filled with the sample values.
If the option output is not included or is specified to be output=value, then the function will return the generated sample as a Vector. If output=plot is specified, then the function will return a density plot of the input random variable together with a histogram of the sample. If output=both is specified, then both the value and the plot will be returned.
If X is a continuous random variable, or an expression that contains a floating point value, or an expression that contains a continuous random variable, then the sample is returned as floating point values. Otherwise, the sample is returned as exact values.
By default, the data are generated according to the rule above. To always generate data numerically, specify the numeric or numeric=true option.
with⁡StudentStatistics:
Straightforward sampling of a random variable.
X≔NormalRandomVariable⁡0,1
X≔_R
A≔Sample⁡X,10
A≔
You can check how well the generated data fit the input model by specifying the output=plot option and comparing the their graphs.
Sample⁡X,105,output=plot
You can also sample an expression involving two random variables.
Y≔NormalRandomVariable⁡0,1
Y≔_R0
Sample⁡exp⁡X⁢Y,10
Consider a discrete random variable.
B≔PoissonRandomVariable⁡3
B≔_R1
Sample⁡Bπ,10
To always generate floating point value data, specify the numeric or numeric=true option.
Sample⁡Bπ,10,numeric
Use the output=both option to obtain both the value and plot of the generated data.
dataset,graph≔Sample⁡B,100,output=both
dataset,graph≔?,PLOT⁡...
dataset
graph
You can also compute the statistics of the generated data.
C≔Sample⁡X2,104
Mean⁡C
0.994862958212511
Median⁡C
0.455147477689335
Skewness⁡C
2.81421618454522
Kurtosis⁡C
14.8537269935385
Variance⁡C
1.96550597257815
StandardDeviation⁡C
1.40196503971324
Quantile⁡C,0.6
0.713125222514264
Stuart, Alan, and Ord, Keith. Kendall's Advanced Theory of Statistics. 6th ed. London: Edward Arnold, 1998. Vol. 1: Distribution Theory.
Walker, Alastair J. New Fast Method for Generating Discrete Random Numbers with Arbitrary Frequency Distributions, Electronic Letters, 10, 127-128.
Walker, Alastair J. An Efficient Method for Generating Discrete Random Variables with General Distributions, ACM Trans. Math. Software, 3, 253-256.
The Student[Statistics][Sample] command was introduced in Maple 18.
For more information on Maple 18 changes, see Updates in Maple 18.
See Also
Statistics[Sample]
Student
Student[Statistics][RandomVariable]
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