Use the zlim argument to image: m <- matrix(1:18,3,6)
par(mfrow = c(2,1)) image(1:6, 1:3, t(m), col = rainbow(20), zlim=c(0,30)) image(1:6, 1:3, t(m+9), col = rainbow(20), zlim=c(0,30)) hope this helps, -- Gregory (Greg) L. Snow Ph.D. Statistical Data Center Intermountain Healthcare greg.s...@imail.org 801.408.8111 > -----Original Message----- > From: r-help-boun...@r-project.org [mailto:r-help-boun...@r- > project.org] On Behalf Of Jorge Hernandez > Sent: Friday, March 26, 2010 4:21 AM > To: r-help@r-project.org > Subject: [R] image() function > > Hello. > > I would like to know how to set the image() function so that it assigns > colors > relative to an absolute scale, as opposed to relative to the values > present > in a particular call to image(). > > For example: > > m <- matrix(1:18,3,6) > > par(mfrow = c(2,1)) > image(1:6, 1:3, t(m), col = rainbow(20)) > image(1:6, 1:3, t(m+9), col = rainbow(20)) > > Then the two images are identical. But the right half of the first > matrix > > coincides (numerically) with the left half of the second. (i.e. > compare > 'm' and 'm+9'.) > > So the question is: how can image() (or some other function) assign the > same color to every incidence of any given value across repeated calls > to image()? > > Thanks in advance. > > JH > > > > *********************************************************************** > *************************************** > > PRIVATE & CONFIDENTIAL: This email and any files transmitted with it > are confidential. Any unauthorized use of the information contained in > t > his email or its attachments is prohibited. If this email is received > in error, please contact the sender and delete the material from your > computer systems. Do not use, copy, or disclose the contents of this > email or any attachments. > > Abu Dhabi Investment Authority (ADIA) does not enter into contracts or > provide undertakings by email. ADIA accepts no responsibility for the > content of this mail to the extent that it is unrelated to its > activities or the same consists of statements or opinions which are > the send > er's own and not made on behalf of ADIA. ADIA does not accept any > liability for any errors or omissions in the content of this email > caused > by electronic and technical failures. Although ADIA has taken > reasonable precautions to ensure that no viruses are present in this > email, ADI > A accepts no responsibility for any loss or damage arising from the use > of this email or its attachments. > > *********************************************************************** > *************************************** > > [[alternative HTML version deleted]] > > ______________________________________________ > R-help@r-project.org mailing list > https://stat.ethz.ch/mailman/listinfo/r-help > PLEASE do read the posting guide http://www.R-project.org/posting- > guide.html > and provide commented, minimal, self-contained, reproducible code. ______________________________________________ R-help@r-project.org mailing list https://stat.ethz.ch/mailman/listinfo/r-help PLEASE do read the posting guide http://www.R-project.org/posting-guide.html and provide commented, minimal, self-contained, reproducible code.
