Weibull probability plot
h = wblplot(X)
wblplot(X) displays a Weibull probability plot of the
X is a matrix,
wblplot displays a plot for each column. Use a Weibull
probability plot to assess visually whether the sample data in
comes from a population with a Weibull distribution. If the sample data has a Weibull
distribution, then the data appears along the reference line. Distributions other than
Weibull can introduce curvature in the plot.
h = wblplot(X) returns handles
to the plotted lines.
Generate a vector
r containing 50 random numbers from a Weibull distribution with parameters
A = 1.2 and
B = 1.5.
rng default; % For reproducibility r = wblrnd(1.2,1.5,50,1);
Create a Weibull probability plot to visually determine if the data comes from a Weibull distribution.
The plot indicates that the data likely comes from a Weibull distribution.
wblplot matches the quantiles of sample data to the quantiles of
a Weibull distribution. The sample data is sorted, scaled logarithmically, and plotted
on the x-axis. The y-axis represents the quantiles of the Weibull distribution,
converted into probability values. Therefore, the y-axis scaling is not linear.
Where the x-axis value is the ith sorted value from a sample of
size N, the y-axis value is the midpoint between evaluation points of
the empirical cumulative distribution function of the data. In the case of uncensored
data, the midpoint is equal to . When the data includes censored observations, use
wblplot superimposes a reference line to assess the linearity of
the plot. The line goes through the first and third quartiles of the data.