Help creating xbar control chart

I have a column vector of data and I am trying to create an xbar control chart from it.

x = (0:1:50)';
y = controlchart(x,'charttype','xbar');

when I try to create the control chart I get the error:

Error using controlchart>getctypeinfo (line 452)

XBAR, S, and R charts required grouped data.

Error in controlchart (line 213)

[cctypes,distn] = getctypeinfo(charttype, grouped);

Error in ESE405_final_project (line 213)

y = controlchart(x,'charttype','xbar');

is there something special that needs to be done for an xbar control chart?

Answer 1

[Dave B]

You specified x as a vector, but controlchart doesn't accept x as a vector. controlchart is going to use means and limits, and it can't do this if x is a vector:

From the help:

controlchart(X) produces an xbar chart of the data in X. If X is a

matrix, its rows should be in time order and should contain replicate

observations taken at the same time. If X is a timeseries object,

the sample at each time should contain replicate observations. The

plot displays the means of each subgroup, or collection of replicate

observations, along with a center line (CL) and lower and upper control

limits (LCL and UCL) to determine if the process is in control. The

control limits are three-sigma limits, with sigma estimated from the

average of the subgroup standard deviations.