How to show the color bar legend in R?

Thank you for your email Zack. When I run the code that you provided, it gives me this error:
Error in if (axes) { : argument is not interpretable as logicalIn addition: Warning message:In if (axes) { :? the condition has length > 1 and only the first element will be used
It seems there is a problem with my R !

? ? ? On Monday, January 26, 2015 11:02 AM, Zack Holden <zaholdenfs at gmail.com> wrote:


? Hi Ferra,Without reproducible code, it's difficult to help. You might have a look at image.plot() in the fields library, and image()
I'm not sure if this is exactly what you're looking for, but here is a quick example of one way to control the image and legend in a plot, using the layout command. You can create a small panel below your main plot and then add your legend there with more control.
I hope this is helpful.
############################################ example code for image plot of volcano datarequire(fields)require(raster)
dat <- raster(volcano)

zc <- as.matrix(seq(minValue(dat), maxValue(dat), length.out=100))
mycolor1 <- two.colors(n=100, start="darkblue", end="red", middle="yellow1", alpha=.9)
layout(matrix(c(1,2), 2, 1, byrow = TRUE), heights=c(4,1), widths=c(4) )layout.show(2)image(dat, axes=F, col=mycolor1, xlab="", ylab="")
par(mar=c(2,4,.1,2))image(zc, col=mycolor1, axes=F, xlab="", ylab="" )
axis(1, at=seq(0,1, length.out=5),? labels=round(seq(minValue(dat), maxValue(dat),length.out=5), digits=0), las=1,? tcl=-.15, padj=-1, cex=1.5) # every .1 corr# end code#############################################


On Mon, Jan 26, 2015 at 10:36 AM, Ferra Xu via R-sig-Geo <r-sig-geo at r-project.org> wrote:

I am still struggling with this question. I appreciate any help from you!


? ? ? On Friday, January 23, 2015 11:00 AM, Ferra Xu <ferra.xu at yahoo.com> wrote:


? Based on the dataset, I computed a 3D kernel (longitude, latitude, depth) and displayed the magnitude with the sphere radius and time with color as follows. I am wondering how I can show the color bar legend.

Also I have problem with the scale of the graph. I need to see if the balls touch or overlap each other from the graph but since the scales are not real I cannot recognize it. How can I correct it?

library(ks)
x <- read.csv("HK1.csv")
y <- x[,1:3]
fhat1 <- kde(x=y)
n <- nrow(x)
col <- grey((n:1)/n)
plot(fhat1, xlim=c(0,500), ylim=c(0,250), zlim=c(0, 4.4))
spheres3d(y, radius=15*(x$magnitude), alpha=1, col= col)

I tried this code (which didn't work):

legend_image <- as.raster(matrix(grey((n:1)/n), ncol=1))
plot(c(0,2),c(0,200),type = 'n', axes = F, xlab = '', ylab = '', main =? 'time scale')
text(x=1.5, y = seq(0,200,l=5), labels = seq(0,200,l=5))
rasterImage(legend_image, 0, 0, 1, 1)

And this one in "plotrix" package:

testcol<- col
col.labels<- seq(0,200, l=5)
color.legend(600, 0, 601,200,col.labels,testcol,gradient="y")

But it gives me this error:

Error in rect(xleft, ybottoms, xright, ytops, col = col, lty = 0) :
plot.new has not been called yet

Also I used legend() in Graphics library:

legend("right", legend=seq(0,200,l=20), fill= colfunc(20), title="Time Scale")

But it gives me the legend in a separate window. Here is my data:

? longitude? ? ? ? latitude? ? ? ? depth? ? ? ? ? ? time? ? ? ? ? magnitude

422.697323? 164.19886? 2.457419? ? 8.083796636? 0.83367586
423.008236? 163.32434? 0.5551326? 37.58477455? 0.893893903
204.733908? 218.36365? 1.9397874? 37.88324312? 0.912809449
203.963056? 218.4808? ? 0.3723791? 43.21775903? 0.926406005
100.727581? 46.60876? ? 1.4022341? 49.41510519? 0.782807523
453.335182? 244.25521? 1.6292517? 51.73779175? 0.903910803
134.909462? 210.96333? 2.2389119? 53.13433521? 0.896529401
135.300562? 212.02055? 0.6739541? 67.55073745? 0.748783521
258.237117? 134.29735? 2.1205291? 76.34032587? 0.735699304
341.305271? 149.26953? 3.718958? ? 94.33975483? 0.849509216
307.138925? 59.60571? ? 0.6311074? 106.9636715? 0.987923188
307.76875? 58.91453? ? 2.6496741? 113.8515307? 0.802115718
415.025535? 217.17398? 1.7155688? 115.7464603? 0.875580325




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