normspec

Normal density plot shading between specifications

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Syntax

p = normspec(specs)
p = normspec(specs,mu,sigma)
p = normspec(specs,mu,sigma,region)
p = normspec(ax,___)
[p,h] = normspec(___)

Description

p = normspec(specs) plots the standard normal density, shading the portion inside the specification limits given by the two-element vector specs, and returns the probability p of the shaded area. If spec has no lower limit, then set specs(1) to –Inf; if spec has no upper limit, then set specs(2) to Inf.

example

p = normspec(specs,mu,sigma) uses a normal density with parameters mu and sigma.

p = normspec(specs,mu,sigma,region) specifies the shading region as either 'inside' or 'outside' the specification limits. The default is 'inside'.

example

p = normspec(ax,___) plots into the axes specified by ax instead of the current axes (gca) using any of the input argument combinations in the previous syntaxes. (since R2024a)

[p,h] = normspec(___) also returns a column vector of chart line objects h. Use h to modify properties of a specific chart line after you create the chart. For a list of properties, see Line Properties.

Examples

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Open Live Script

Create a standard normal density plot, shading the portion inside the specification limits [-1,1].

p = normspec([-1,1])

Figure contains an axes object. The axes object with title Probability Between Limits is 0.68269, xlabel Critical Value, ylabel Density contains 5 objects of type patch, line. This object represents Normal.

p = 
0.6827
Open Live Script

Create a normal density plot, shading the portion outside the specification limits.

For example, consider a production process that fills cans of paint. The average amount of paint in any can is 1 gallon, but variability in the process produces a standard deviation of 2 ounces (2/128 gallons). Create a normal density plot, shading the portion corresponding to the probability that the cans will be filled under specification by 3 or more ounces.

p = normspec([1-3/128,Inf],1,2/128,'outside')

Figure contains an axes object. The axes object with title Probability Less than Lower Bound is 0.066807, xlabel Critical Value, ylabel Density contains 4 objects of type patch, line. This object represents Normal.

p = 
0.0668

Input Arguments

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Specification limits, specified as a two-element numeric vector. Set specs(1) to –Inf if there is no lower limit; set specs(2) to Inf if there is no upper limit.

Data Types: single | double

Mean of the normal distribution, specified as a scalar value.

Data Types: single | double

Standard deviation of the normal distribution, specified as a positive scalar value.

Data Types: single | double

Shading region, specified as either 'inside' or 'outside'. The function normspec shades the region either 'inside' or 'outside' the specification limits.

Since R2024a

Target axes, specified as an Axes object. If you do not specify the axes, then normspec uses the current axes (gca).

Output Arguments

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Probability of the shaded area, returned as a nonnegative scalar value.

One or more chart line objects, returned as a scalar or vector. These objects are unique identifiers that you use to query and modify properties of a specific chart line. For a list of properties, see Line Properties.

Version History

Introduced before R2006a

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See Also

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