show_plot() bars not aligned w/ values below.

[sfd99]

Hi Alastair,

the inspectdf PKG is really USEFUL!.

But a show_plot() quirk...

try:

unique(mtcars$carb) 
[1] 4 1 2 3 6 8
 inspect_num(mtcars) %>% show_plot()

See?.
The vertical bars in the CARB plot
are not "aligned" with the unique value markers below,
(in the x-axis).

The bars are all slightly "displaced" to the right...
(not "on top" of the unique CARB values: 4 1 2 3 6 8 ).
Even Zoomming the size of the Rstudio [Plots] Panel
doesn't help.

Same problem with columns for:
AM, GEAR , VS and CYL ...etc

Hope you can help.
Thanks Alastair!

sfd99
San Francisco
latest Rstudio/R/Ubuntu Linux
inspectdf 0.0.11

[alastairrushworth]

Hey @sfd99 thanks for raising the issue! and sorry for the long delay in responding. Although it looks a bit strange once visualised, I think this is the expected behaviour - the histogram binning is carried out by base R's hist() function, and those bins won't necessarily center over the values when there are only a small number of unique values. For example, hist(mtcars$carb, breaks = 20) and hist(mtcars$cyl, breaks = 20) both generate images that are consistent with inspectdf.

However, I do see the problem, and I think there should be a feature to make it obvious that the histogram doesn't make much sense. I'll have a think and get back if there is an update. thanks again :)

[sfd99]

Hi Alastair,

Thanks for the response.

Yes,
pls do let us know
if you find a solution to this weird hist quirk.
Looking forward to it!.

Great PKG...

Best,
sfd99
San Francisco
latest Rstudio/R/Ubuntu Linux
inspectdf 0.0.11

[sfd99]

I found a starting point
to this misalignment hist problem:

https://stackoverflow.com/questions/41486027/how-to-align-the-bars-of-a-histogram-with-the-x-axis

Take a look!...

Did this Dr, Google query:
how to align histogram bars with the corresponding values in R

One of the quoted solutions there,
when x-values are int:

This will center the hist bar
directly on top of the x-axis value:

data <- data.frame(number = c(5, 10, 11 ,12,12,12,13,15,15))
ggplot(data,aes(x = number)) + geom_histogram(binwidth = 0.5)

But there must be better R ways...
SFd99

[sfd99]

And finally,
one last, good possible sol:

ggplot(mtcars, aes(x = factor(cyl))) +
geom_bar()

VIA:
https://www.guru99.com/r-bar-chart-histogram.html

[alastairrushworth]

thanks! I think a general solution to this is more complex than it sounds. It's not uncommon to have int columns that have very many unique values, where it wouldn't make sense to treat them as categories. Perhaps there could be a simple rule eg. fewer than 10 unique values and int --> count frequencies rather than using buckets. I'm not sure.

[sfd99]

Hi Alastair,

Yes, I agree.

That rule (your comment above),
could be a possible solution
to the hist alignment quirk...

If it works in a generic way,
the inspectdf PKG:: show_plot() would be the first
to solve it. :-)

thanks!
SFd99