Overlay histogram with density curve

problem ：

I am trying to make a histogram of density values and overlay that with the curve of a density function (not the density estimate). I am trying to make a histogram of the density value and compare it with the curve of the density function （ Not density estimates ） superposition .

Using a simple standard normal example, here is some data: Use a simple standard normal example , Here are some data ：

x <- rnorm(1000)

I can do: I can ：

q <- qplot( x, geom="histogram")q + stat_function( fun = dnorm )

but this gives the scale of the histogram in frequencies and not densities. But this gives the frequency of the histogram, not the proportion of the density .with ..density.. I can get the proper scale on the histogram: And ..density.. I can get the appropriate scale on the histogram ：

q <- qplot( x,..density.., geom="histogram")q

But now this gives an error: But now this gives an error ：

q + stat_function( fun = dnorm )

Is there something I am not seeing? Is there anything I haven't seen ？

Another question, is there a way to plot the curve of a function, like curve() , but then not as layer? Another question , Is there any way to plot the curve of a function , such as curve() , But not as a layer ？

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Solution ：

Reference resources ： https://stackoom.com/en/question/NrjG