Bug 299403

Summary:	R images have a white vertical line to the right
Product:	[Applications] cantor	Reporter:	Christopher Yeleighton <giecrilj>
Component:	r-backend	Assignee:	Alexander Rieder <alexanderrieder>
Status:	RESOLVED UPSTREAM
Severity:	normal	CC:	alexanderrieder, filipe, warquark
Priority:	NOR
Version First Reported In:	0.3
Target Milestone:	---
Platform:	openSUSE
OS:	Linux
Latest Commit:		Version Fixed/Implemented In:
Sentry Crash Report:
Attachments:	the image saved from Cantor

Description Christopher Yeleighton 2012-05-04 20:06:00 UTC

R images displayed in Cantor have a thin white vertical line to the right.

Reproducible: Always

Steps to Reproduce:
  1. Tell Cantor to create a new R sheet.
  2. Tell R to execute:
x <- seq(-pi, pi, len=50)
y <- x
image (x, y, outer (x, y, function (x, y) x + y))


Actual Results:  
  2. The image has a vertical white line between 2 and 3.

Expected Results:  
  3. A color image of (x + y).

This anomaly does not occur in command-line R.

Workaround: 

image (x, y, outer (x, y, function (x, y) x + y), useRaster=TRUE)

Comment 1 Christopher Yeleighton 2012-05-04 20:18:58 UTC

Created attachment 70863 [details]
the image saved from Cantor

Comment 2 Nikita Sirgienko 2018-06-10 15:41:24 UTC

Hello Christopher.

I don't think, that is Cantor bug, because I was able to reproduced white line in command-line R with this code by manipulating size of image window.

Also, according documentation (https://stat.ethz.ch/R-manual/R-devel/library/graphics/html/image.html)
"...Images for large z on a regular grid are rendered more efficiently with useRaster = TRUE and can prevent rare anti-aliasing artifacts..."
So, I think you notice one of this "rare anti-aliasing artifacts", because for example for "x <- seq(-pi, pi, len=49)" or "x <- seq(-pi, pi, len=51)" we have image without white lines.

So, as I see, it's documented behavior of R, so I close it as upstream bug.