[R] colors, lines, characters .... documentation

[Henrik Bengtsson]

Oops, I forgot to check that plotSymbols(TRUE) worked with R --vanilla
and it didn't as some of you already noticed; intToHex() and
intToOct() were not defined (they're in my R.classes bundle at
http://www.braju.com/R/). Below is a self-contained version that
should work.

Cheers

Henrik Bengtsson

----------------------------------------------------
BEGIN code
----------------------------------------------------
plotSymbols <- function(interactive=FALSE) {
  ASCII <- c("\000", sapply(1:255, function(i)
parse(text=paste("\"\\",
                    structure(i,class="octmode"), "\"",
sep=""))[[1]]));
  intToChar <- function(i) {
    ASCII[i %% 256 + 1];
  }

  as.character.hexmode <- function(x) {
    hexDigit <- c(0:9, "A", "B", "C", "D", "E", "F")
    isna <- is.na(x)
    y <- x[!isna]
    ans0 <- character(length(y))
    z <- NULL
    while (any(y > 0) | is.null(z)) {
      z <- y%%16
      y <- floor(y/16)
      ans0 <- paste(hexDigit[z + 1], ans0, sep = "")
    }
    ans <- rep(NA, length(x))
    ans[!isna] <- ans0
    ans
  }
  
  intToHex <- function(x) {
    y <- as.integer(x);
    class(y) <- "hexmode";
    y <- as.character(y);
    dim(y) <- dim(x);
    y;
  }

  as.character.octmode <- function(x, ...) {
    isna <- is.na(x)
    y <- x[!isna]
    ans0 <- character(length(y))
    z <- NULL
    while (any(y > 0) | is.null(z)) {
      z <- y%%8
      y <- floor(y/8)
      ans0 <- paste(z, ans0, sep="")
    }
    ans <- rep(as.character(NA), length(x))
    ans[!isna] <- ans0
    ans
  }
  
  intToOct <- function(x) {
    y <- as.integer(x);
    class(y) <- "octmode";
    y <- as.character(y);
    dim(y) <- dim(x);
    y;
  }
    
  interactive <- interactive && interactive();

  i <- 0:255;
  ncol <-16;
  
  top <- 3 + 2*interactive;
  opar <- par(cex.axis=0.7, mar=c(3,3,top,3)+0.1)
  on.exit(par(opar))

  plot(i%%ncol,1+i%/%ncol, pch=i, xlim=c(0,ncol-1), xlab="", ylab="", 
 
axes=FALSE);
  axis(1, at=0:15)
  axis(2, at=1:16, labels=0:15*16, las=2)
  axis(3, at=0:15)
  axis(4, at=1:16, labels=0:15*16+15, las=2)
  if (interactive) {
    title(main="Click on a symbol to add it to the data frame. Click
in margin to quit!", cex.main=0.8, line=3.5);
    df <- list();
    usr <- par("usr");
    ready <- FALSE;
    while (!ready) {
      click <- locator(n=1);
      print(click)
      x <- click$x;
      y <- click$y - 1;
      ready <- !(x > -0.5 && x < 15.5 && y > -0.5 && y < 15.5);
      if (!ready) {
        x <- round(x);
        y <- round(y);
        z <- 16*y + x;
        ch  <- intToChar(z);
        dec <- as.character(z); 
        hex <- intToHex(z);
        oct <- intToOct(z);
        spc <- paste(rep("0", 2-nchar(hex)), collapse="");
        hex <- paste(spc, hex, sep="");
        spc <- paste(rep("0", 3-nchar(oct)), collapse="");
        oct <- paste(spc, oct, sep="");
        df$ch  <- c(df$ch , ch );
        df$dec <- c(df$dec, dec);
        df$hex <- c(df$hex, hex);
        df$oct <- c(df$oct, oct);

        if (nchar(ch) == 0) ch <- " ";
        spc <- paste(rep(" ", 3-nchar(dec)), collapse="");
        dec <- paste(spc, dec, sep="");
        cat("Selected ASCII character '", ch, "' ", dec, " 0x", hex, 
                                                 " \\", oct, "\n",
sep="");
      }
    }
    return(df);
  }

  invisible();
} # plotSymbols()
----------------------------------------------------
END code
----------------------------------------------------

> -----Original Message-----
> From: r-help-bounces at stat.math.ethz.ch 
> [mailto:r-help-bounces at stat.math.ethz.ch] On Behalf Of Henrik 
> Bengtsson
> Sent: den 24 mars 2004 16:31
> To: 'Monica Palaseanu-Lovejoy'; r-help at stat.math.ethz.ch
> Subject: RE: [R] colors, lines, characters .... documentation
> 
> 
> Hi, many questions at once there, but here some help 
> regarding *symbols*. 
> 
> I've pasted a function plotSymbols() that shows all symbols 
> available. Note that the the symbols pch >= 128 are system 
> dependent so you should not expect them to look the same on 
> Windows, Mac and Unix. Try also plotSymbols(TRUE). To turn of 
> the click-bell do 'options(locatorBell=FALSE)' (see ?locator).
> 
> Cheers
> 
> Henrik
>

[snip old code]

>
> > -----Original Message-----
> > From: r-help-bounces at stat.math.ethz.ch
> > [mailto:r-help-bounces at stat.math.ethz.ch] On Behalf Of Monica 
> > Palaseanu-Lovejoy
> > Sent: den 24 mars 2004 16:06
> > To: r-help at stat.math.ethz.ch
> > Subject: [R] colors, lines, characters .... documentation
> > 
> > 
> > Hi,
> > 
> > Very so often when i am plotting something, doing a histogram, or
> > whatever i am struggling to find out which are the numbers for 
> > different colors, palette names, types of lines, symbols, etc. Is 
> > there any documentation on line with all these numbers / names 
> > and the associated symbol / color???
> > 
> > For example if i am using the command image it uses a palette
> > from red to yellow, with red the lowest value, and yellow the
> highest 
> > value. What if i want a reverse palette, with green the lowest
value
> 
> > and yellow middle values and red highest value??? Or much more
> > simple, just yellow lowest value and red highest value???
> > 
> > Thank you for assistance,
> > 
> > Monica
> > 
> > ______________________________________________
> > R-help at stat.math.ethz.ch mailing list
> > https://www.stat.math.ethz.ch/mailma> n/listinfo/r-help
> > PLEASE 
> > do read the posting guide! 
> > http://www.R-project.org/posting-guide.html
> > 
> >
> 
> ______________________________________________
> R-help at stat.math.ethz.ch mailing list 
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> PLEASE 
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> 
>